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in category surgery

103 results found. For more information, click each entry to expand.

21: Impact of Systemic Arterial Pressure, Collateral Vascular Resistance and Degree of Carotid Stenosis on Cerebral Blood Flow, Reserve Blood Flow, Critical Carotid Stenosis, Cerebral Ischemia and Carotid Hemodynamics
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Posted 26 Feb 2021

Impact of Systemic Arterial Pressure, Collateral Vascular Resistance and Degree of Carotid Stenosis on Cerebral Blood Flow, Reserve Blood Flow, Critical Carotid Stenosis, Cerebral Ischemia and Carotid Hemodynamics
74 downloads medRxiv surgery

Joseph P Archie

IntroductionCarotid artery stenosis related stroke is a major health care concern. Current risk management strategies for patients with asymptomatic carotid stenosis include ultrasound surveillance and occasionally an estimate of cerebral blood flow reserve. Other patient specific hemodynamic variables may be predictive of ischemic stroke risk. This study, based on a cerebral blood flow hemodynamic model, aims to investigate the impact of systemic arterial pressure, collateral vascular resistance and degree of carotid stenosis on cerebral ischemic risk, cerebrovascular blood flow reserve, critical carotid artery stenosis, carotid artery blood flow and carotid stenosis hemodynamics. MethodsThis study uses a three-component (carotid, collateral, brain) energy conservation cerebrovascular fluid mechanics model in combination with the Lassen cerebral blood flow autoregulation model that predicts cerebral blood flow in patients with carotid stenosis. It is a two-phase model, zone A when regional cerebral blood flow is autoregulated at normal values and zone B when cerebral blood flow is below normal and dependent on collateral perfusion pressure. The model solution with carotid artery occlusion defines collateral vascular resistance, with patient specific values calculated from clinical pressure measurements. In addition to cerebral blood flow the model predicts critical stenosis values and carotid and collateral blood flows as a function of systemic arterial pressure and percent diameter stenosis. Carotid stenosis blood flow velocities and energy dissipation are predicted from carotid blood flow solutions. ResultsThe model defines patient specific collateral vascular resistance, cerebral vascular resistance and critical carotid stenosis. It predicts carotid vascular resistance to be non-linearly proportional to area carotid stenosis. Solutions include reserve cerebral blood flow, the carotid and collateral components of cerebral blood flow, criteria for cerebral ischemia and carotid stenosis hemodynamics. Critical carotid stenosis is determined by mean systemic arterial pressure and the Lassen autoregulation threshold cerebral perfusion pressure. Critical stenosis values range from 61% to 76% diameter stenosis when mean systemic arterial pressures are 80mmHg to 120mmHg and the cerebral autoregulation pressure threshold is 50mmHg. When carotid stenosis is less than critical, cerebral blood flow is maintained normal and the ratios of carotid blood flow to collateral blood flow are inversely proportional to the carotid to collateral vascular resistance ratios. At stenosis greater than the critical, carotid blood flow is not adequate to maintain normal cerebral blood flow, cerebral blood flow is primarily collateral flow, all reserve blood flow is collateral and prevention of cerebral ischemia requires adequate collateral flow. Patient specific collateral vascular resistance values less than 1.0 predict normal cerebral blood flow at moderate to severe stenosis. Values greater than 1.0 predicts cerebral ischemia to be dependent on the magnitude of collateral vascular resistance. Systemic arterial pressure is a major determinant of carotid stenosis hemodynamics. Carotid blood flow velocities increase with carotid stenosis and have progressively higher variance depending on collateral blood flow as predicted by collateral vascular resistance. Turbulent flow energy dissipation intensity is similarly inversely proportional to collateral vascular resistance at severe carotid stenosis. ConclusionsCerebral, collateral and carotid blood flow solutions are determined by systemic arterial pressure, collateral vascular resistance and degree of stenosis. Critical carotid stenosis, systemic arterial pressure and collateral vascular resistance are primary determinants of cerebral ischemic risk in patients with significant carotid stenosis.

22: Timing and Dose of Pharmacological Thromboprophylaxis in Adult Trauma Patients: Perceptions, Barriers, and Experience of Saudi Arabia Practicing Physicians
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Posted 29 Jan 2021

Timing and Dose of Pharmacological Thromboprophylaxis in Adult Trauma Patients: Perceptions, Barriers, and Experience of Saudi Arabia Practicing Physicians
71 downloads medRxiv surgery

Marwa R Amer, Mohammed Bawazeer, Khalid Maghrabi, Rashid Amin, Edward De Vol, Mohammed Hijazi

Background: Pharmacological venous thromboembolism prophylaxis (PVTE-Px) in trauma care is challenging and frequently delayed until post injury bleeding risk is perceived to be sufficiently low; yet data for optimal initiation time is lacking. This study assessed practice pattern of PVTE-Px initiation time and dose in traumatic brain injury (TBI), spinal cord injury (SCI), and non-operative (NOR) solid organ injuries. Methods: Multicenter, cross sectional, observational, survey-based study involving intensivists, trauma surgeons, general surgeons, spine orthopedics, and neurosurgeons practicing in trauma centers. The data of demographics, PVTE-Px timing and dose, and five clinical case scenarios were obtained. Analyses were stratified by early initiators vs. late initiators and logistic regression models were used to identify factors associated with early initiation of PVTE-Px. Results: Of 102 physicians (29 % response rate), most respondents were intensivists (63.7%) and surgeons (who are general and trauma surgeons) (22.5%); majority were consultants (58%), practicing at level 1 trauma centers (40.6%) or academic teaching hospitals (45.1%). A third of respondents (34.2%) indicated that decision to initiate PVTE-Px in TBI and SCI was made by a consensus between surgical, critical care, and neurosurgical services. For patients with NOR solid organ injuries, 34.2% of respondents indicated trauma surgeons initiated the decision on PVTE-Px timing. About 53.7% of the respondents considered their PVTE-Px practice as appropriate, half used combined mechanical and PVTE-Px (57.1%), 52% preferred enoxaparin (40 mg once daily), and only 6.5% used anti-Xa level to guide enoxaparin prophylactic dose. Responses to clinical cases varied. For TBI and TBI with intracranial pressure monitor , 40.3% and 45.6% of the respondents were early initiators with stable repeated head computed tomography [CT], respectively. For SCI, most respondents were early initiators without repeated CT spine (36.8%). With regards to NOR solid organ injuries [gunshot wound to the liver and grade IV splenic injuries], 49.1% and 36.4% of respondents were early initiators without a repeat CT abdomen. Conclusions: Variations were observed in PVTE-Px initiation time influenced by trauma type. Our findings suggested enoxaparin is preferred in a standard prophylactic dose. More robust data from randomized trials are needed and the use of clinicians judgment is recommended.

23: A comparative analysis of the health, financial, equity, and cost-effectiveness impacts of maxillofacial surgery in Guinea
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Posted 26 Mar 2021

A comparative analysis of the health, financial, equity, and cost-effectiveness impacts of maxillofacial surgery in Guinea
69 downloads medRxiv surgery

Mirjam Hamer, Dennis Alcorn, Ibrahima Diallo, Fatoumata B Y Bah, Alhassane Conde, Lancine Traore, Etienne Faya Millimouno, Chelsea Peacock, Chris Glasgo, Peter E Linz, Mark G Shrime, Omar Raphiou Diallo

Background: Non-governmental organizations (NGOs) play a substantive role in the delivery of surgical services in in low- and middle-income countries (LMICs). Assessment of their outcomes, especially as they relate to outcomes of surgery done in country, remains limited. Methods: A prospective analysis of maxillofacial surgery in Guinea. Outcomes of interest were changes in patient health, subjective well-being, and financial status; hardship financing and catastrophic expenditure; equitable distribution of surgical access; and cost-effectiveness. Results: We followed 569 patients requiring maxillofacial surgery in Conakry, Guinea, 114 of whom got care at local university hospitals, and 455 of whom got their care with Mercy Ships, a surgical NGO. Patients were followed for between three months (local) and one year (NGO). All patients reported significant improvement in objective and subjective measures of health and in financial status. Approximately half had to borrow and sell to get care, with NGO patients borrowing less, on average. However, NGO patients faced more risk of catastrophic expenditure (41.2% vs. 28.1%, p < 0.001). NGO patients were significantly poorer, whether financial status was measured by asset wealth (p = 0.014) or monthly income (p < 0.001). Finally, surgical care by the NGO was cost effective. Conclusions: In a prospective analysis of surgical patients in an LMIC, we find that surgery improves health and financial well-being. NGOs may be able to reach patients who would not be able to get care through their local system; however, this comes at a cost of increased initial financial risk. Finally, NGO-based surgical care is cost-effective.

24: Impact of Asian and black donor and recipient ethnicity on the outcomes after deceased donor kidney transplantation in the United Kingdom
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Posted 07 May 2021

Impact of Asian and black donor and recipient ethnicity on the outcomes after deceased donor kidney transplantation in the United Kingdom
68 downloads medRxiv surgery

Abdul Rahman Hakeem, Sonal Asthana, Rachel Johnson, Chloe Brown, Niaz Ahmad

Background: Patients of Asian and black ethnicity face disadvantage on the renal transplant waiting list in the United Kingdom, because of lack of HLA and blood group matched donors from an overwhelmingly white deceased donor pool. This study evaluates outcomes of renal allografts arising from Asian and black donors. Methods: The UK Transplant Registry was analysed for adult deceased donor kidney only transplants performed during January 2001 to December 2015. Results: Asian and black ethnicity patients constituted 12.4% and 6.7% of all deceased donor recipients but only 1.6% and 1.2% of all deceased donors, respectively. Across all recipients, and unsurprisingly given the predominantly white recipient pool, HLA matching was superior for grafts from white donors than from Asian and black donors (p less than 0.0001). Unadjusted survival analysis demonstrated significantly inferior long-term allograft outcomes associated with Asian and black donors, compared to white donors (7 year graft survival 71.9%, 74.0% and 80.5%; log rank p 0.0007, respectively). On Cox regression analysis, Asian donor (HR 1.37 for Asian donors vs. white donors as baseline) and black recipient (HR 1.21 for black recipients vs. white recipient as baseline) ethnicities were associated with poorer outcomes than white counterparts, and on ethnicity matching, compared with the white donor to white recipient baseline group and adjusting for other donor and recipient factors, 5 year graft outcomes were significantly poorer for black donor to black (HR 1.92 (1.11 to 3.32), p 0.02), Asian donor to white recipient (HR 1.56 (1.09 to 2.24), p 0.016) and white donor-black recipient (HR 1.22 (1.05 to 1.42), p 0.011) combinations in decreasing order of worse unadjusted 5 year graft survival. Conclusions: Increased deceased donation among ethnic minority communities would benefit the entire recipient pool by increasing the numbers of available organs and may specifically benefit the Asian and black recipients by increasing the numbers of blood group and HLA compatible grafts for allocation but may not improve allograft outcomes.

25: Unplanned Hospital Visits after Ambulatory Surgical Care
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Posted 12 Mar 2021

Unplanned Hospital Visits after Ambulatory Surgical Care
67 downloads medRxiv surgery

Tasce Bongiovanni, Craig Parzynski, Isuru Ranasinghe, Michael A. Steinman, Joseph S. Ross

Objectives: We sought to assess the rate of unplanned hospital visits among patients undergoing ambulatory surgery. Summary Background Data: The majority of surgeries performed in the United States now take place in outpatient settings. Post-discharge hospital visit rates have been shown to vary widely, suggesting variation in surgical or discharge care quality. Complicating efforts to address quality, most facilities and surgeons are unaware of their patients' hospital visits after surgery since patients may present to a different hospital. Methods: We used state-level, administrative data from the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project from California to assess unplanned hospital visits after ambulatory surgery. To compare rates across centers, we determined the age, sex, and procedure-adjusted rates of hospital visits for each facility using 2-level, hierarchical, generalized linear models using methods similar to existing Centers for Medicare and Medicaid Services measures. Results: Among a total of 1,260,619 ambulatory same-day surgeries from 440 surgical facilities, the risk adjusted 30-day rate of unplanned hospital visits was 4.8%, with emergency department visits of 3.1% and hospital admissions of 1.7%. Several patient characteristics were associated with increased risk of unplanned hospitals visits, including increased age, increased number of comorbidities (using the Elixhauser score), and type of procedure (p<0.001). Conclusions: The overall rate unplanned hospital visits within 30 days after same-day surgery is low but variable, suggesting a difference in the quality of care provided. Further, these rates are higher among specific patient populations and procedure types, suggesting areas for targeted improvement.

26: Perforated appendicitis: can it be a bedside diagnosis?
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Posted 01 May 2020

Perforated appendicitis: can it be a bedside diagnosis?
66 downloads medRxiv surgery

Maham Taraiq, Sara Malik, Eesha Yaqoob, Mehwish changez, Saad Javed, Ramlah Ghazanfor, Ghulam Khadija, Javaria Malik, Bilal Ahmad, Khawaja Rafay Ghazanfor

ABSTRACT INTRODUCTION: Appendicitis remains one of the most common causes of acute abdomen worldwide. It presents as a spectrum of disease ranging from an acutely inflamed appendix to a perforated one. where acutely inflamed can be managed conservatively, a perforated appendix always needs surgery to prevent complications like pelvic abscesses. Bedside diagnosis remains relevant in our setup. AIMS AND OBJECTIVES: To determine whether history, clinical examination, and basic laboratory investigations can help in confident bedside diagnosis of perforated appendicitis especially in the absence of sophisticated diagnostic modalities. MATERIALS AND METHODS: A retrospective case-control study was conducted. Hospital records of patients who underwent open appendectomy in the year 2016 were reviewed. Two groups of 100 patients each were made based on per operative findings. Appendices having macroscopic holes in the base or tip were labeled as perforated. Group A had acutely inflamed appendix and group b had perforated appendix. The patient's demographic details were taken from hospital admission tickets. Findings of history and examination were retrieved from treating resident and operating surgeon's notes. Data were analyzed through SPSS. RESULTS: Out of 200 patients the total number of males was 102 (51%) and females were 98 (49%). Mean age was 24.13+9.73 in males and 18.7+ 6.4 in females of group A and 26.0+10.1 in males and 20.56+7.53 in females of Group B. Group B showed a significant delay in presentation to emergency after the onset of pain (P = 0.022). Upon history and clinical examination, the presence of anorexia, malaise, generalized abdominal pain, guarding, mass in right iliac fossa were significantly associated with perforation. Whereas gender, fever, vomiting, and dysuria showed no association with perforation. CONCLUSION: Bedside conventional methods of history taking and examination remain a useful tool in anticipating perforated appendicitis. This helps surgeons in planning incisions and prioritizing patients on heavy operating lists. This remains especially relevant in resource-constrained setups where sophisticated modalities like CT scans are largely unavailable. KEYWORDS: Perforated appendicitis, Acute appendicitis

27: Soft robotic steerable micro-catheter for the endovascular treatment of cerebral disorders
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Posted 01 Jul 2021

Soft robotic steerable micro-catheter for the endovascular treatment of cerebral disorders
66 downloads medRxiv surgery

Gopesh Tilvawala, Jessica H Wen, David Santiago-Dieppa, Bernard Yan, J. Scott Pannell, Alexander Khalessi, Alexander Norbash, James Friend

Catheters used for endovascular navigation in interventional procedures lack dexterity at the distal tip. Neurointerventionists, in particular, encounter challenges in up to 25% of aneurysm cases largely due to the inability to steer and navigate the tip of the micro-catheters through tortuous vasculature to access aneurysms. We overcome this problem with sub-millimeter diameter, hydraulically-actuated hyperelastic polymer devices at the distal tip of micro-catheters to enable active steerability. Controlled by hand, the devices offer complete 3D orientation of the tip. Using pressures up to 400 kPa (4 atm) we demonstrate guidewire-free navigation, access, and coil deployment in vivo, offering safety, ease of use, and design flexibility absent in other approaches to endovascular intervention. We demonstrate the ability of our device to navigate through vessels and to deliver embolization coils to the cerebral vessels in a live porcine model. This indicates the potential for microhydraulic soft robotics to solve difficult access and treatment problems in endovascular intervention.

28: Portuguese Inguinal Hernia Cohort (PINE) study
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Posted 22 Dec 2020

Portuguese Inguinal Hernia Cohort (PINE) study
60 downloads medRxiv surgery

PT Surg – Portuguese Surgical Research Collaborative, J Simões, AA João, JM Azevedo, M Peyroteo, M Cunha, B Vieira, N Gonçalves, J Costa, AS Soares, JS Pimenta, M Romano, AM Cinza, I Miguel, AR Martins, G Fialho, M Reia, FC Borges, CF Monteiro, AC Soares, P Sousa, S Frade, L Matos, JM Carvas, SF Martins, X Sousa, C. Rodrigues, JR Carvalho, IC Gil, L Castro, N Rombo, AC Quintela, HM Ribeiro, R Parreira, P Santos, F Caires, A Torre, S.C. Rodrigues, AH Guimarães, MF Carvalho, MA Pimentel, DC Santos, CF Ramos, C Cunha, C. Azevedo

PurposeRecent comprehensive guidelines have been published on the management of inguinal hernia. Contrary to other European countries, no Portuguese hernia registry exists. This represents an opportunity to assess outcomes of hernia surgery in the Portuguese population. The primary aim is to define the prevalence of chronic pain after elective inguinal hernia repair. The secondary aims are to identify risk factors for chronic pain after elective inguinal hernia repair, to characterise the management of elective inguinal hernia in public Portuguese hospitals. MethodsProspective national cohort study of patients submitted to elective inguinal hernia repair. The primary outcome is the prevalence of chronic postoperative inguinal pain, according to the EuraHS QoL questionnaire at 3 months postoperatively. The study will be delivered in all Portuguese regions through a collaborative research network. Four 2-week inclusion periods will be open for recruitment. A site-specific questionnaire will capture procedure volume and logistical facilities for hernia surgery. ConclusionThis protocol describes the methodology of a prospective cohort study on the elective management of inguinal hernia. It discusses key challenges and describes how the results will impact future investigation. The study will be conducted across a nationwide collaborative research network, with prospective quality assurance and data validation strategies. It will provide the basis for a more accurate prediction of chronic postoperative inguinal pain and the research on adequate patient selection strategies for surgery and therapeutic strategies for postoperative pain.

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Posted 22 Jun 2021

59 downloads medRxiv surgery

Luiz F Frascino, Jonas D.C. Severi, Fernanda R.F. Lorenzzato, Hamilton L.X. Funes

Background: The association of prosthetic meshes in the abdominal wall repair , reducing the recurrence rates in an impactful way, has become an almost mandatory routine for the success of these surgeries. After decades using non-biological synthetic implants, from the 90s onwards biological acellular membranes of animal or human origin were introduced , beginning a new era in abdominal wall defects correction . Methods: Thirty patients underwent repair for different abdominal wall deformities, with acellular matrices of bovine pericardium, in a total of 40 anatomically individualized implants. The median follow-up was 22 months, with patients evaluated clinically and radiologically. In three cases, biopsies of the implanted areas were performed, allowing histological analysis of the material. Results: There was no recurrence of hernias in any of the cases, both clinically and radiologically. There was also no record of hematomas, infections or any phenomenon of a local or systemic reaction nature. Radiologically, it was not possible to visualize the matrices at the implantation site in any of the analysed postoperative periods. Biopsies showed important tissue neoformation replacing the implanted membranes, with important deposition of collagen, normal-looking cellularized tissue, and absence of foreign body reactions. Conclusions: The analysed matrices showed similarity to other biological membranes described in the international literature. Representing an important update and conceptual evolution, biological matrices must be incorporated into the therapeutic arsenal in abdominal wall repairs. Key Words: Biological prosthetic mesh; Biological acellular matrix; Acellular bovine pericardium matrix; Abdominal hernia; Ventral hernia repair;

30: An effect of the COVID-19 pandemic: significantly more complicated appendicitis due to delayed presentation of patients!
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Posted 25 Jan 2021

An effect of the COVID-19 pandemic: significantly more complicated appendicitis due to delayed presentation of patients!
59 downloads medRxiv surgery

Marie Burgard, Floryn Cherbanyk, Konstantinos Nassiopoulos, Sonaz Malekzadeh, Francois Pugin, Bernhard Egger

AIMS OF THE STUDY: The novel coronavirus pandemic has affected emergency department consultations for surgical pathologies. The aim of our study was to compare the number of acute appendicitis cases and the proportion of complicated appendicitis before and during the COVID 19 pandemic. METHODS: We retrospectively analyzed all data collected from a multicenter database of patients presenting to the emergency department for acute appendicitis during the COVID-19 pandemic from March 12 to June 6, 2020, and compared these data with those from the same periods in 2017, 2018, and 2019. The number of acute appendicitis cases, proportion of complicated appendicitis, and pre and postoperative patient characteristics were evaluated. RESULTS: A total of 306 patients were included in this evaluation. Sixtyfive patients presented during the 2020 COVID-19 pandemic lockdown (group A), and 241 patients in previous years (group B: 2017 to 2019). The number of consultations for acute appendicitis decreased by almost 20 percent during the pandemic compared with previous periods, with a significant increase in complicated appendicitis (52% in group A versus 20% in group B, p < 0,001.). Comparing the two groups, significant differences were also noted in the duration of symptoms ( symptoms > 48h in 61% and 26% , p < 0,001), the intervention time ( 77 vs 61 minutes, p = 0,002), length of hospital stay ( hospitalization of > 2 days in 63% and 32%, p < 0.001) and duration of antibiotic treatment ( antibiotics > 3 days in 36% and 24% p = 0.001). CONCLUSIONS: The COVID 19 pandemic resulted in a decreased number of consultations for acute appendicitis, with a higher proportion of complicated appendicitis, most likely due to patient delay in consulting the emergency department at symptom onset. Patients and general practitioners should be aware of this problem to avoid a time delay from initial symptoms to consultation.

31: Surgery & COVID-19: A rapid scoping review of the impact of COVID-19 on surgical services during public health emergencies
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Posted 04 Dec 2020

Surgery & COVID-19: A rapid scoping review of the impact of COVID-19 on surgical services during public health emergencies
52 downloads medRxiv surgery

Connor O'Rielly, Joshua Ng Kamstra, Ania Kania-Richmond, Joseph C Dort, Jonathan White, Jill Robert, Mary Brindle, Khara M Sauro

Background: Healthcare systems globally have been challenged by the COVID-19 pandemic, necessitating the reorganization of surgical services to free capacity within healthcare systems. Objectives: To understand how surgical services have been reorganized during and following public health emergencies, and the consequences of these changes for patients, healthcare providers and healthcare systems. Methods: This rapid scoping review searched academic databases and grey literature sources to identify studies examining surgical service delivery during public health emergencies including COVID-19, and the impact on patients, providers and healthcare systems. Recommendations and guidelines were excluded. Screening was completed in partial (title, abstract) or complete (full text) duplicate following pilot reviews of 50 articles to ensure reliable application of eligibility criteria. Results: One hundred and thirty-two studies were included in this review; 111 described reorganization of surgical services, 55 described the consequences of reorganizing surgical services and six reported actions taken to rebuild surgical capacity in public health emergencies. Reorganizations of surgical services were grouped under six domains: case selection/triage, PPE regulations and practice, workforce composition and deployment, outpatient and inpatient patient care, resident and fellow education, and the hospital or clinical environment. Service reorganizations led to large reductions in non-urgent surgical volumes, increases in surgical wait times, and impacted medical training (i.e., reduced case involvement) and patient outcomes (e.g., increases in pain). Strategies for rebuilding surgical capacity were scarce, but focused on the availability of staff, PPE, and patient readiness for surgery as key factors to consider before resuming services. Conclusions: Reorganization of surgical services in response to public health emergencies appears to be context-dependent and has far-reaching consequences that must be better understood in order to optimize future health system responses to public health emergencies.

32: Direct Molecular Analysis of In Vivo and Freshly Excised Tissues in Human Surgeries with the MasSpec Pen Technology
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Posted 16 Dec 2020

Direct Molecular Analysis of In Vivo and Freshly Excised Tissues in Human Surgeries with the MasSpec Pen Technology
51 downloads medRxiv surgery

Jialing Zhang, Marta Sans, Rachel J. DeHoog, Kyana Y. Garza, Mary E. King, Clara L. Feider, Alena Bensussan, Michael F. Keating, John Q. Lin, Sydney Povilaitis, Nitesh Katta, Thomas E. Milner, Wendong Yu, Chandandeep Nagi, Sadhna Dhingra, Christopher Pirko, Kirtan A. Brahmbhatt, George Van Buren, Stacey Carter, William E. Fisher, Alastair Thompson, Raymon H. Grogan, James Suliburk, Livia S Eberlin

Intraoperative tissue analysis is critical to guide surgical procedures and improve patient outcomes. Here, we describe the clinical translation and intraoperative use of the MasSpec Pen technology for direct molecular analysis of in vivo and freshly excised tissues in the operating room. In this study, the MasSpec Pen was used by surgeons and surgical staff during 100 surgeries over a 12-month period, allowing rapid detection of rich mass spectral profiles from 715 in vivo and ex vivo analyses performed on thyroid, parathyroid, lymph node, breast, pancreatic, and bile duct tissues during parathyroidectomies, thyroidectomies, breast, and pancreatic neoplasia surgeries. The MasSpec Pen enabled gentle extraction and sensitive detection of various molecular species including small metabolites and lipids using a droplet of sterile water without causing apparent tissue damage. Notably, effective molecular analysis was achieved while no limitations to sequential histologic tissue analysis were identified and no device-related complications were reported for any of the patients. Collectively, this study shows that the MasSpec Pen system can be successfully incorporated into the operating room, allowing direct detection of rich molecular profiles from tissues with a seconds-long turnaround time that could be inform surgical and clinical decisions without disrupting tissue analysis workflows.

33: The validation of the original and modified Caprini score in COVID-19 patients
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Posted 23 Jun 2020

The validation of the original and modified Caprini score in COVID-19 patients
49 downloads medRxiv surgery

Sergey Tsaplin, Ilya Schastlivtsev, Kirill Lobastov, Sergey Zhuravlev, Victor Barinov, Joseph Caprini

Objective. The study aimed to validate the original Caprini score and its modifications considering coronavirus disease (COVID-19) as a severe prothrombotic condition in patients admitted to the hospital with confirmed infection. Methods. The relevant data were extracted from the electronic medical records with the implemented Caprini score and were evaluated retrospectively. The score was calculated twice: by the physician at the admission and by the investigator at discharge or after death. The second calculation at discharge, considered additional risk factors that occurred during inpatient treatment. Besides the original Caprini score (a version of 2005), the modified version added the elevation of D-dimer and specific scores for COVID-19 as follows: 2 points for asymptomatic, 3 points for symptomatic and 5 points for symptomatic infection with positive D-dimer, were evaluated in a retrospective manner. The primary endpoint was symptomatic venous thromboembolism (VTE) confirmed by appropriate imaging testing or dissection. The secondary endpoint included the unfavorable outcome as a combination of symptomatic VTE, admission to the intensive care unit, the requirement for invasive mechanical ventilation, and death. The association of eight different versions of the Caprini score with outcomes was evaluated. Results. Totally 168 patients (83 males and 85 females at the age of 58.3{+/-}12.7 years old) were admitted to the hospital between April 30 and May 29, 2020, and were discharged or died up to the time of data analysis. The original Caprini score varied between 2-12 (5.4{+/-}1.8) at the admission and between 2-15 (5.9{+/-}2.5) at discharge or death. The presence of the virus increased these scores and resulted in an increased score with the maximal value for those including COVID-19 points (10.0{+/-}3.0). Patients received prophylactic (2.4%), intermediate (76.8%), or therapeutic (20.8%) doses of enoxaparin. Despite this, the symptomatic VTE was detected in 11 (6.5%) and unfavorable outcomes in 31 (18.5%) patients. The Caprini score of all eight versions demonstrated a significant association with VTE with the highest predictability for the original scale when assessed at discharge. Supplementation of the original score by elevated D-dimer improved predictability only at the admission. Four versions of the Caprini score calculated at the admission had a significant correlation with the unfavorable outcome with the minor advantages of specific COVID-19 points. Conclusion. The study identified a significant correlation between the Caprini score and the risk of VTE or unfavorable outcomes in COVID-19 patients. All models, including specific COVID-19 scores, showed high predictability with minor differences.

34: Predicting thermal injury patient outcomes in a Tertiary-Care Burn Centre, Pakistan
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Posted 22 Jun 2021

Predicting thermal injury patient outcomes in a Tertiary-Care Burn Centre, Pakistan
49 downloads medRxiv surgery

Mohammad Suleman Bajwa, Muhammad Sohail, Hamza Ali, Umer Nazir, Muhammad Mustehsan Bashir

Objectives: To explore candidate parameters for their ability to predict survival and length of hospital stay (LOS) in thermal burns patients, to prepare multivariate predictive models for these two outcomes, and to compare performance of native models to other models. Methods: A retrospective cohort study was undertaken based on record review. Data was extracted from files of patients admitted to a tertiary-care burn centre in Lahore, Pakistan from January 1, 2020 to October 31, 2020. Univariate preselection was used to prepare multivariate logistic regression models for each outcome of interest (survival and LOS). Multivariate models were tested and compared to other models. Results: Increasing TBSA of burn was positively associated with reduced survival and prolonged length of stay. Advancing age and full-thickness burns independently predicted decreased survival. Burn etiology showed prognostic value: petrol-flame burns predicted decreased survival and prolonged LOS; scald was associated with improved survival-odds and shorter LOS. The Survival-model consisted of (1) Baux score, (2) TBSA>40% and (3) serum albumin <3.5g/dl (AUC=0.968, Nagelkerke R^2=0.797). The LOS-model consisted of (1) TBSA^2 and (2) serum albumin concentration (AUC= 0.832, Nagelkerke R^2 =0.408). In tests of discrimination and calibration, native models prepared for survival and LOS outcomes outperformed other models applicable to our dataset. Conclusion: Data from a South Asian burn center has been used to explore factors influencing prognosis for their utility in predictive models for survival and the duration of hospital stay. The significant prognostic roles of TBSA, age, inhalational injury, burn-depth, etiology of burn, anatomic site of burn, hypoalbuminemia and other biochemical parameters were observed. These tools hold significance in guiding healthcare policy and in communications with patients and their families.

35: Impact of neoadjuvant chemoradiotherapy on postoperative clinically significant pancreatic fistula. A systemic review and updated meta-analysis.
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Posted 16 Dec 2020

Impact of neoadjuvant chemoradiotherapy on postoperative clinically significant pancreatic fistula. A systemic review and updated meta-analysis.
47 downloads medRxiv surgery


Background: Pancreatic fistula is one of the main complications after pancreatic surgery and the leading cause of morbidity and mortality after pancreatic surgery. There are many pieces of evidence emerging out from retrospective studies and metanalysis that neoadjuvant chemoradiation decreases rates of clinically significant postoperative pancreatic fistula. Aims and objectives: The primary aim of our analysis was to do a systemic review and updated meta-analysis of literature published in the last 10 years and look for the association of neoadjuvant chemoradiation and risk of subsequent clinically significant pancreatic fistula. Methods: EMBASE, MEDLINE, and the Cochrane Database were searched for Studies comparing outcomes in patients receiving neoadjuvant chemoradiotherapy first with those patients who received surgery first in case of pancreatic cancer. A systemic review and Metanalysis were done according to MOOSE and PRISMA guidelines. Heterogeneity was measured using Q tests and I2, and p < 0.10 was determined as significant. The Odds ratios (OR) and Risk Ratios (RR) were calculated for dichotomous data as per the requirement, and weighted mean differences (WMD) were used for continuous variables. Nonrandomized trials were accessed for bias using the New Castle Ottawa scale. Publication bias was studied using funnel plots. The meta-analysis was conducted using Open Review Manager 5.4. Results: Twenty-six studies including 17021 patients finally included in the analysis. 339 patients out of a total of 3386 developed clinically significant pancreatic fistula in the neoadjuvant first group. 2342 patients out of 13335 patients developed clinically significant pancreatic fistula in the surgery first group. Neoadjuvant treatment significantly reduced the risk of subsequent clinically significant pancreatic fistula. (p= <0.0001). The number of patients with soft pancreas was significantly higher in the surgery first group. (p <0.0001). Pancreatic duct diameter mentioned in only two studies but there was no significant difference between both groups. [p=1].Blood loss was significantly more in the surgery first group.[ p <0.0001]. There was no difference in pancreaticoduodenectomy or distal pancreatectomy performed between both groups. (p=0.82). There was no difference in the number of borderline resectable pancreatic tumors between both groups. (p= 0.34). There was no difference in overall grade 3/grade 4 complications rate between both groups. (p= 0.39). Conclusion: Neoadjuvant treatments may be responsible for the lower rates of clinically significant pancreatic fistula after subsequent surgery.

36: Post operative acute kidney injury in abdominal Surgeries. A retrospective analysis of single center in western India.
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Posted 06 Jan 2021

Post operative acute kidney injury in abdominal Surgeries. A retrospective analysis of single center in western India.
47 downloads medRxiv surgery


AIMThe aim of our study was to evaluate the incidence and causative factors for acute kidney injury in abdominal surgeries. Material and MethodsAll the abdominal surgeries performed between April 2018 to December 2020, in our institution have been analyzed for acute kidney injury. Acute kidney injury defined according to acute kidney injury network classification. Categorical variables were evaluated by chi-square t-test or fishers t-test wherever appropriate and continuous variables by Mann Whitney U test for nonparametric data and student t-test for parametric test after skewness and kurtosis analysis. Statistical analysis was done using SPSS version 23. P< 0.05 was considered statistically significant. ResultsWe performed 402 gastrointestinal and hepatobiliary surgery from April 2018 to December 2020. After exclusion 372 patients were included in the study population. 20 patients (5.37%) were defined as having acute kidney injury according to acute kidney injury network classifications. On univariate analysis acute kidney injury was associated with open surgery (p= 0.003), Intraoperative hypotension (p<0.001), Colorectal surgeries (p<0.0001), Emergency surgery (p=0.028), CDC grade of surgery (p<0.001), increased used to blood products (p=0.001), higher ASA grade (p<0.0001), increased operative time(p<0.0001). On multivariate logistic regression analysis higher ASA grade (p<0.0001) and increased operative time (0.049) independently predicted acute kidney injury. Acute kidney injury was also significantly associated with 90 days mortality. (p= <0.0001). ConclusionPost-operative acute kidney injury was associated with significant mortality in abdominal surgery. Higher ASA grades and increased operative time predicted acute kidney injury.

37: Early changes in immune cell metabolism and function are a hallmark of sleeve gastrectomy: a prospective human study
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Posted 04 Aug 2020

Early changes in immune cell metabolism and function are a hallmark of sleeve gastrectomy: a prospective human study
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Tammy Lo, Eleanor J. M. Rudge, Robert P Chase, Renuka Subramaniam, Keyvan Heshmati, Elizabeth M. Lucey, Alison M. Weigl, Otatade J. Iyoha-Bello, Chelsea O. Ituah, Emily J. Benjamin, Seth W. McNutt, Leena Sathe, Leanna Farnam, Benjamin A. Raby, Ali Tavakkoli, Damien C. Croteau-Chonka, Eric G. Sheu

Objective To characterize longitudinal changes in blood biomarkers, leukocyte composition, and gene expression following laparoscopic sleeve gastrectomy (LSG). Background LSG is an effective treatment for obesity, leading to sustainable weight loss and improvements in obesity-related co-morbidities and inflammatory profiles. However, the effects of LSG on immune function and metabolism remain uncertain. Methods Prospective data was collected from 23 enrolled human subjects from a single institution. Parameters of weight, co-morbidities, and trends in blood biomarkers and leukocyte subsets were observed from pre-operative baseline to one year in three-month follow-up intervals. RNA-sequencing was performed on pairs of whole blood samples from the first six subjects of the study (baseline and three months post-surgery) to identify genome-wide gene expression changes associated with undergoing LSG. Results LSG led to a significant decrease in mean total body weight loss (18.1%) at three months and among diabetic subjects a reduction in HbA1c. Improvements in clinical inflammatory and hormonal biomarkers were demonstrated as early as three months after LSG. A reduction in neutrophil-lymphocyte ratio was observed, driven by a reduction in absolute neutrophil counts. Gene set enrichment analyses of differential whole blood gene expression demonstrated that after three months, LSG induced transcriptomic changes not only in inflammatory cytokine pathways but also in several key metabolic pathways related to energy metabolism. Conclusions LSG induces significant changes in the composition and metabolism of immune cells as early as three months post-operatively. Further evaluation is required of bariatric surgery's effects on immunometabolism and consequences for host defense and metabolic disease.

38: Spinal Anesthesia is Safe and Cost-effective for Laparoscopic Appendectomy in Children: A Case-Control Study
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Posted 21 Oct 2020

Spinal Anesthesia is Safe and Cost-effective for Laparoscopic Appendectomy in Children: A Case-Control Study
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Md Jafrul Hannan, Kohinoor Parveen, Alak Nandy, Md Samiul Hasan

STRUCTURED ABSTRACTO_ST_ABSBackgroundC_ST_ABSOwing to the widespread use of general anesthesia, administration of spinal anesthesia in pediatrics is not widely practiced. Yet there is ample positive evidence demonstrating its safety, effectiveness and success. ObjectiveThe objective of this study is to demonstrate that laparoscopic appendectomies are successful under spinal anesthesia and elicit clear advantages over general anesthesia. MethodsThis was a retrospective analysis of 77 pediatric (5-8 year old) laparoscopic appendectomies that took place in a Hospital, Chittagong, Bangladesh in 2019. Approximately half of the patients underwent spinal anesthesia while the other half underwent general anesthesia. Variables such as surgery and operation theatre times, pain score, incidence of post-surgery vomiting, analgesic usage, discharge times and hospital costs were recorded. Statistical analysis was used to analyze the data as a function of form of anesthesia. ResultsThe probability of vomiting when using spinal compared to general anesthesia was much lower within the first 5 hours (P < .001) and after 6 hours (P = .008) of operation. Highly significant difference (P < .001) was observed in the total costs of the procedures. A significantly higher likelihood of patients being discharged the same day of the procedure was noted if spinal anesthesia was used (P = .008). ConclusionsSpinal anesthesia is superior to general anesthesia for pediatric laparoscopic appendectomies. Patient comfort is improved through a significant decrease in vomiting. This enables more rapid hospital discharges and a significant cost saving, without compromising the outcome of the procedure. MINI-ABSTRACTSpinal anesthesia is seldom used for laparoscopy in children. This retrospective case-controlled study compared spinal anesthesia with general anesthesia in children between 5 and 8 years of age. Spinal anesthesia proved to be safer and cost-effective for laparoscopy in children.

39: Nonresponse adjustment using clinical and perioperative patient characteristics is critical for understanding post-discharge opioid consumption
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Posted 07 Jul 2021

Nonresponse adjustment using clinical and perioperative patient characteristics is critical for understanding post-discharge opioid consumption
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Chris J. Kennedy, Jayson S. Marwaha, P. Nina Scalise, Kortney A. Robinson, Brandon Booth, Aaron Fleishman, Larry A Nathanson, Gabriel A. Brat

Background: Post-discharge opioid consumption is an important source of data in guiding appropriate opioid prescribing guidelines, but its collection is tedious and requires significant resources. Furthermore, the reliability of post-discharge opioid consumption surveys is unclear. Our group developed an automated short messaging service (SMS)-to-web survey for collecting this data from patients. In this study, we assessed its effectiveness in estimating opioid consumption by performing causal adjustment and comparison to a phone-based survey as reference. Methods: Patients who underwent surgical procedures at our institution from 2019-2020 were sent an SMS message with a link to a secure web survey to quantify opioids consumed after discharge. Several patient factors extracted from the EHR were tested for association with survey response. Following targeted learning (TL) nonresponse adjustment using these EHR-based factors, opioid consumption survey results were compared to a prior telephone-based survey at our institution as a reference. Results: 6,553 patients were included. Opioid consumption was measured in 2,883 (44%), including 1,342 (20.5%) through survey response. Characteristics associated with inability to measure opioid consumption included age, length of stay, race, tobacco use, and missing preoperative assessment. Among the top 10 procedures by volume, EHR-based TL nonresponse bias adjustment corrected the median opioid consumption reported by an average of 57%, and corrected the 75th percentile of reported consumption by an average of 11%. This brought median estimates for 6/10 procedures closer to telephone survey-based consumption estimates, and 75th percentile estimates for 3/10 procedures closer to telephone survey-based consumption estimates. Conclusion: We found that applying electronic health record (EHR)-based machine learning nonresponse bias adjustment is essential for debiased opioid consumption estimates from patient surveys. After adjustment, post-discharge surveys can generate reliable opioid consumption estimates. Clinical factors from the EHR combined with TL adjustment appropriately capture differences between responders and nonresponders and should be used prior to generalizing or applying opioid consumption estimates to patient care.

40: Colorectal Cancer Disparities: A Systematic Review and Meta-Analysis
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Posted 06 Jul 2021

Colorectal Cancer Disparities: A Systematic Review and Meta-Analysis
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Solomiya Syvyk, Chris Wirtalla, Rachel Rapaport Kelz, Sanford Roberts, Caitlin Finn

IMPORTANCE Colorectal Cancer (CRC) disparities continue to mostly impact vulnerable populations. Across the CRC continuum, most focus has been attributed to interventions in prevention, detection, and diagnosis. Varying surgical outcomes has emerged as an important contributing factor to CRC disparities. OBJECTIVE To evaluate the distribution of publications across the CRC care continuum, examine interventional studies related to CRC Surgery, and synthesize findings in studies evaluating CRC disparities in Surgery. DATA SOURCES We searched PubMed for prospective or retrospective studies reporting data on colorectal cancer disparities. STUDY SELECTION Studies were selected if: (1) articles used US-sourced data (2) articles were published in the English language (3) Subjects included humans only or data. MAIN OUTCOMES AND MEASURES Odds ratios for receipt of surgery for black vs. white patients were pooled from studies that performed multivariate analysis. Subgroup analysis was performed per procedure type. RESULTS No publications regarding interventions associated with improvements in colorectal cancer surgery were found. Of the 1600 articles identified, an analysis was conducted from 18 publications. It included 89,214 black patients and 646,990 white patients. Black patients were significantly less likely to receive surgical treatment for CRC than white patients. This was confirmed in the sensitivity analysis by cancer site (colon vs rectum). CONCLUSIONS AND RELEVANCE Based on the results, the majority of studies on CRC disparities have focused on access to prevention, diagnosis and screening. Considering the impact of varying surgical outcomes on vulnerable populations, it should be considered to shift research focus from process-oriented interventions to outcomes.

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