Machine learning improves prediction of postoperative outcomes after gastrointestinal surgery: a systematic review and meta-analysis.

BACKGROUND: Machine learning (ML) approaches have become increasingly popular in predicting surgical outcomes. However, it is unknown whether they are superior to traditional statistical methods such as logistic regression (LR). This study aimed to perform a systematic review and meta-analysis to compare the performance of ML vs LR models in predicting postoperative outcomes for patients undergoing gastrointestinal (GI) surgery. METHODS: A systematic search of Embase, MEDLINE, Cochrane, Web of Science, and Google Scholar was performed through December 2022. The primary outcome was the discriminatory performance of ML vs LR models as measured by the area under the receiver operating characteristic curve (AUC). A meta-analysis was then performed using a random effects model. RESULTS: A total of 62 LR models and 143 ML models were included across 38 studies. On average, the best-performing ML models had a significantly higher AUC than the LR models (ΔAUC, 0.07; 95% CI, 0.04-0.09; P < .001). Similarly, on average, the best-performing ML models had a significantly higher logit (AUC) than the LR models (Δlogit [AUC], 0.41; 95% CI, 0.23-0.58; P < .001). Approximately half of studies (44%) were found to have a low risk of bias. Upon a subset analysis of only low-risk studies, the difference in logit (AUC) remained significant (ML vs LR, Δlogit [AUC], 0.40; 95% CI, 0.14-0.66; P = .009). CONCLUSION: We found a significant improvement in discriminatory ability when using ML over LR algorithms in predicting postoperative outcomes for patients undergoing GI surgery. Subsequent efforts should establish standardized protocols for both developing and reporting studies using ML models and explore the practical implementation of these models.

Development and Validation of Prediction Models and Risk Calculators for Posthepatectomy Liver Failure and Postoperative Complications Using a Diverse International Cohort of Major Hepatectomies.

OBJECTIVE: The study aim was to develop and validate models to predict clinically significant posthepatectomy liver failure (PHLF) and serious complications [a Comprehensive Complication Index (CCI)>40] using preoperative and intraoperative variables. BACKGROUND: PHLF is a serious complication after major hepatectomy but does not comprehensively capture a patient's postoperative course. Adding the CCI as an additional metric can account for complications unrelated to liver function. METHODS: The cohort included adult patients who underwent major hepatectomies at 12 international centers (2010-2020). After splitting the data into training and validation sets (70:30), models for PHLF and a CCI>40 were fit using logistic regression with a lasso penalty on the training cohort. The models were then evaluated on the validation data set. RESULTS: Among 2192 patients, 185 (8.4%) had clinically significant PHLF and 160 (7.3%) had a CCI>40. The PHLF model had an area under the curve (AUC) of 0.80, calibration slope of 0.95, and calibration-in-the-large of -0.09, while the CCI model had an AUC of 0.76, calibration slope of 0.88, and calibration-in-the-large of 0.02. When the models were provided only preoperative variables to predict PHLF and a CCI>40, this resulted in similar AUCs of 0.78 and 0.71, respectively. Both models were used to build 2 risk calculators with the option to include or exclude intraoperative variables ( PHLF Risk Calculator; CCI>40 Risk Calculator ). CONCLUSIONS: Using an international cohort of major hepatectomy patients, we used preoperative and intraoperative variables to develop and internally validate multivariable models to predict clinically significant PHLF and a CCI>40 with good discrimination and calibration.

Role of preoperative 3D rendering for minimally invasive parenchyma sparing liver resections.

BACKGROUND: 3D rendering (3DR) represents a promising approach to plan surgical strategies. The study aimed to compare the results of minimally invasive liver resections (MILS) in patients with 3DR versus conventional 2D CT-scan. METHODS: We performed 118 3DR for various indications; the patients underwent a preoperative tri-phasic CT-scan and rendered with Synapse3D® Software. Fifty-six patients undergoing MILS with pre-operative 3DR were compared to a similar cohort of 127 patients undergoing conventional pre-operative 2D CT-scan using the propensity score matching (PSM) analysis. RESULTS: The 3DR mandated pre-operative surgical plan variations in 33.9% cases, contraindicated surgery in 12.7%, providing a new surgical indication in 5.9% previously excluded cases. PSM identified 39 patients in both groups with comparable results in terms of conversion rates, blood loss, blood transfusions, parenchymal R1-margins, grade ≥3 Clavien-Dindo complications, 90-days mortality, and hospital stay respectively in 3DR and conventional 2D. Operative time was significantly increased in the 3DR group (402 vs. 347 min, p = 0.020). Vascular R1 resections were 25.6% vs 7.7% (p = 0.068), while the conversion rate was 0% vs 10.2% (p = 0.058), respectively, for 3DR group vs conventional 2D. CONCLUSION: 3DR may help in surgical planning increasing resectability rate while reducing conversion rates, allowing the precise identification of anatomical landmarks in minimally invasive parenchyma-preserving liver resections.

Using the Comprehensive Complication Index to Rethink the ISGLS Criteria for Post-hepatectomy Liver Failure in an International Cohort of Major Hepatectomies.

OBJECTIVE: To compare different criteria for post-hepatectomy liver failure (PHLF) and evaluate the association between International Study Group of Liver Surgery (ISGLS) PHLF and the Comprehensive Complication Index (CCI)" and 90-day mortality. SUMMARY OF BACKGROUND DATA: PHLF is a serious complication following hepatic resection. Multiple criteria have been developed to characterize PHLF. METHODS: Adults who underwent major hepatectomies at twelve international centers (2010-2020) were included. We identified patients who met criteria for PHLF based on three definitions: 1) ISGLS, 2) Balzan (INR > 1.7 and bilirubin > 2.92mg/dL) or 3) Mullen (peak bilirubin >7mg/dL). We compared the 90-day mortality and major morbidity predicted by each definition. We then used logistic regression to determine the odds of CCI>40 and 90-day mortality associated with ISGLS grades. RESULTS: Among 1646 included patients, 19 (1.1%) met Balzan, 68 (4.1%) met Mullen, and 444 (27.0%) met ISGLS criteria for PHLF. Of the three definitions, the ISGLS criteria best predicted 90-day mortality (AUC = 0.72; sensitivity 69.4%). Patients with ISGLS grades B&C were at increased odds of CCI > 40 (grade B OR 4.0; 95% CI: 2.2-7.2; grade C OR 137.0; 95% CI: 59.2-317.4). Patients with ISGLS grade C were at increased odds of 90-day mortality (OR 113.6; 95% CI: 55.6-232.1). Grade A was not associated with CCI> 40 or 90-day mortality. CONCLUSIONS: In this diverse international cohort of major hepatectomies, ISGLS grade A was not associated with 90-day mortality or high CCI, calling into question the current classification of patients in this group as having clinically significant PHLF.

Postgraduate Surgical Education in East, Central, and Southern Africa: A Needs Assessment Survey.

BACKGROUND: The Lancet Commission on Global Surgery has identified workforce development as an important component of National Surgical Plans to advance the treatment of surgical disease in low- and middle-income countries. The goal of our study is to identify priorities of surgeon educators in the region so that collaboration and intervention may be appropriately targeted. STUDY DESIGN: The American College of Surgeons Operation Giving Back, in collaboration with leaders of the College of Surgeons of Eastern, Central and Southern Africa (COSECSA), developed a survey to assess the needs and limitations of surgical educators working under their organizational purview. COSECSA members were invited to complete an online survey to identify and prioritize factors within 5 domains: (1) Curriculum Development, (2) Faculty Development, (3) Structured Educational Content, (4) Skills and Simulation Training, and (5) Trainee Assessment and Feedback. RESULTS: One-hundred sixty-six responses were received after 3 calls for participation, representing all countries in which COSECSA operates. The majority of respondents (78%) work in tertiary referral centers. Areas of greatest perceived need were identified in the Faculty Development and Skills and Simulation domains. Although responses differed between domains, clinical responsibilities, cost, and technical support were commonly cited as barriers to development. CONCLUSIONS: This needs assessment identified educational needs and priorities of COSECSA surgeons. Our study will serve as a foundation for interventions aimed at further improving graduate surgical education and ultimately patient care in the region.

Effectiveness of an immersive virtual reality environment on curricular training for complex cognitive skills in liver surgery: a multicentric crossover randomized trial.

BACKGROUND: Virtual reality (VR) is increasingly used in surgical education, but evidence of its benefits in complex cognitive training compared to conventional 3-dimensional (3D) visualization methods is lacking. The objective of this study is to assess the impact of 3D liver models rendered visible by VR or desktop interfaces (DIs) on residents' performance in clinical decision-making. METHOD: From September 2020 to April 2021, a single-blinded, crossover randomized educational intervention trial was conducted at two university hospitals in Belgium and Italy. A proficiency-based stepwise curriculum for preoperative liver surgery planning was developed for general surgery residents. After completing the training, residents were randomized in one of two assessment sequences to evaluate ten real clinical scenarios. RESULTS: Among the 50 participants, 46 (23 juniors/23 seniors) completed the training and were randomized. Forty residents (86.96%) achieved proficiency in decision-making. The accuracy of virtual surgical planning using VR was higher than that using DI in both groups A (8.43 ± 1.03 vs 6.86 ± 1.79, p < 0.001) and B (8.08 ± 0.9 vs 6.52 ± 1.37, p < 0.001). CONCLUSION: Proficiency-based curricular training for liver surgery planning successfully resulted in the acquisition of complex cognitive skills. VR was superior to DI visualization of 3D models in decision-making. GOV ID: NCT04959630.

Evidence-based Guidelines on the Use of Virtual Surgical Education Pertaining to the Domains of Cognition and Curriculum, Psychomotor Skills Training, and Faculty Development and Mentorship.

OBJECTIVE: To identify, categorize, and evaluate the quality of literature, and to provide evidence-based guidelines on virtual surgical education within the cognitive and curricula, psychomotor, and faculty development and mentorship domains. SUMMARY OF BACKGROUND DATA: During the coronavirus disease 2019 pandemic, utilizing virtual learning modalities is expanding rapidly. Although the innovative methods must be considered to bridge the surgical education gap, a framework is needed to avoid expansion of virtual education without proper supporting evidence in some areas. METHODS: The Association for Surgical Education formed an ad-hoc research group to evaluate the quality and methodology of the current literature on virtual education and to build evidence-based guidelines by utilizing the SiGN methodology. We identified patient/problem-intervention-comparison-outcome-style questions, conducted systematic literature reviews using PubMed, EMBASE, and Education Resources information Center databases. Then we formulated evidence-based recommendations, assessed the quality of evidence using Grading of Recommendations, Assessment, Development, and Evaluation, Newcastle-Ottawa Scale for Education, and Kirkpatrick ratings, and conducted Delphi consensus to validate the recommendations. RESULTS: Eleven patient/problem-intervention-comparison-outcome-style questions were designed by the expert committees. After screening 4723 articles by the review committee, 241 articles met inclusion criteria for full article reviews, and 166 studies were included and categorized into 3 domains: cognition and curricula (n = 92), psychomotor, (n = 119), and faculty development and mentorship (n = 119). Sixteen evidence-based recommendations were formulated and validated by an external expert panel. CONCLUSION: The evidence-based guidelines developed using SiGN methodology, provide a set of recommendations for surgical training societies, training programs, and educators on utilizing virtual surgical education and highlights the area of needs for further investigation.

Unifying the Hepatopancreatobiliary Surgery Fellowship Curriculum via Delphi Consensus.

BACKGROUND: Hepatopancreatobiliary (HPB) Fellowship training in the Americas consists of 3 distinctive routes with variable curricula: Surgical Oncology Fellowship via the Society of Surgical Oncology (SSO), Abdominal Transplant Surgery Fellowship via the American Society of Transplant Surgeons (ASTS), and HPB Fellowship via the Americas Hepato-Pancreato-Biliary Association (AHPBA). Our objective was to establish a pan-American consensus among HPB surgeons, surgical oncologists, abdominal transplant surgeons, and general surgery residency program directors (GSPDs) on a core knowledge curriculum for HPB fellowship, and to identify topics appropriate for general surgery residency and subspecialty beyond HPB fellowship. STUDY DESIGN: A 3-round modified Delphi process was used. Baseline statements were developed by the Education and Training Committee of the AHPBA, in collaboration with representatives of the SSO, ASTS, and GSPDs. The expert panel, consisting of members of the 3 societies together with GSPDs, rated the statements on a 5-point Likert scale and suggested editing or adding new statements. A statement was included in the final curriculum when Cronbach's alpha value was ≥ 0.8 and ≥ 80% of the panel agreed on inclusion. RESULTS: The response rate was 100% for the first round, and 98% for the second and third rounds. Eighty-nine of 138 proposed statements were included in the final HPB fellowship curriculum. Curricula for general surgery residency and subspecialty beyond HPB fellowship included 50 and 29 statements, respectively. CONCLUSIONS: A multinational consensus on core knowledge for an HPB fellowship curriculum was achieved via the modified Delphi method. This core curriculum may be used to standardize HPB fellowship training across different pathways in the Americas.

Cancers Metastatic to the Liver.

The liver is a common site of metastatic cancer spread, and metastatic lesions are the most common malignant liver tumors. Diagnosis of liver metastases often is established based on clinical assessment, laboratory tests, and appropriate imaging. Surgical resection is the treatment of choice for resectable colorectal and neuroendocrine liver metastases. Long-term survival outcome data after treatment of hepatic metastases of noncolorectal non-neuroendocrine tumors are less robust. The treatment strategy for patients with liver metastases should be determined case by case in a multidisciplinary setting.

Post-operative morbidity following pancreatic duct occlusion without anastomosis after pancreaticoduodenectomy: a systematic review and meta-analysis.

BACKGROUND: Pancreatic duct occlusion (PDO) without anastomosis is a technique proposed to mitigate the clinical consequences of postoperative pancreatic fistulas (POPF) after pancreaticoduodenectomy. The aim of this study was to appraise the morbidity following PDO through a systematic review and meta-analysis. METHODS: A systematic search of MEDLINE, Embase, and Web Of Science identified studies reporting outcomes of PDO following pancreaticoduodenectomy. Pooled prevalence rates of postoperative complications and mortality were computed using random-effect modeling. Meta-regression analyses were performed to examine the impact of moderators on the overall estimates. RESULTS: Sixteen studies involving 1000 patients were included. Pooled postoperative mortality was 2.7%. A POPF was reported in 29.7% of the patients. Clinically relevant POPFs occurred in 13.5% of the patients, while intra-abdominal abscess and haemorrhages occurred in 6.7% and 5.5% of the patients, respectively. Re-operation was necessary in 7.6% of the patients. Postoperatively new onset diabetes occurred in 15.8% of patients, more frequently after the use of chemical substances for PDO (p = 0.003). CONCLUSIONS: PDO is associated with significant morbidity including new onset of post-operative diabetes. The risk of new onset post-operative diabetes is associated with the use of chemical substance for PDO. Further evidence is needed to evaluate the potential benefits of PDO in patients at high risk of POPF.

Surgical education interventions in liver surgery: a systematic review.

The objective of the study was to identify and to evaluate the impact of educational interventions to learn and train liver surgery outside the operating room. A systematic literature search was conducted using PubMed, Web of Science, Embase, and ERIC databases from inception to September 2019 according to the PRISMA guidelines. Studies describing and assessing outcomes of educational interventions in liver surgery, outside the operating room, were included. Neither language nor date of publication restriction was applied. Methodological quality was appraised using NOS-E (Newcastle-Ottawa Scale for Education), and the level of evidence was evaluated based on GRADE (Grades of Recommendation Assessment, Development, and Evaluation) standards. Of the 10,403 screened abstracts, 53 articles were eligible for inclusion, comprising 27 descriptive studies (50.9%), 14 case series assessing any relevant outcome (26.4%), 8 non-randomized controlled trials (15.1%), and 4 randomized controlled studies (7.5%). Almost half (26/53) of the studies did not include any participants, while the remainder of the publications (27/53) involved 1306 learners. The majority of the studies focused on cognitive knowledge (31/53) and/or psychomotor skills training (24/53). Only one publication assessed affective skills. The GRADE score was very low or low in most articles (46/53). Five studies were scored high (5-6) according to NOS-E. Two studies reported data regarding the reliability and validity of employed assessment tools. High-quality studies, particularly well-designed randomized controlled trials that evaluate the effectiveness of simulation-based training on learner behavior and patient outcomes in liver surgery, are still lacking. Forthcoming studies should use robust assessment tools supported by validity evidence.

Key components of a hepatobiliary surgery curriculum for general surgery residents: results of the FULCRUM International Delphi consensus.

BACKGROUND: In general surgery residency, hepatobiliary training varies significantly across the world. The aim of this study was to establish an international consensus among hepatobiliary surgeons on components of a hepatobiliary curriculum for general surgery residents. METHODS: A three-round modified Delphi technique was employed. Fifty-two hepatobiliary surgeons involved in general surgery training programs were invited. An initial questionnaire was developed by a group of experts in hepatobiliary and educational research after a systematic literature review. It comprised 90 statements about knowledge, technical skills, attitudes, and postoperative care. Panelists could add or alter items. The survey was delivered electronically and the panel was instructed to score the items based on 5-point Likert scale. Consensus was reached when at least 80% of panelists agreed on a statement with Cronbach's alpha value >0.8. RESULTS: Forty-one (79%) experts have participated. Sixteen panelists are based in Asia, 14 in Europe, and 11 in the Americas. Eighty percent of all proposed skills (81/101) were considered fundamental including knowledge (39/43), technical skills (16/32), attitude (15/15), and postoperative care (11/11). CONCLUSION: An international consensus was achieved on components of a hepatobiliary curriculum. Acquiring broad knowledge is fundamental during residency. Advanced liver resection techniques require specialized hepatobiliary training.

Laparoscopic Liver Surgery Training Course on Thiel-Embalmed Human Cadavers: Program Evaluation, Trainer's Long-Term Feedback and Steps Forward.

OBJECTIVES: The purpose of this study was to evaluate the feedback of participants upon laparoscopic liver surgery (LLS) course on Thiel-embalmed human bodies. METHODS: From 2010 to 2017, ten LLS masterclasses have been organized by the Department of Hepatobiliary Surgery at Ghent University Hospital. A 23-question anonymous survey was electronically sent to 119 participants between November 2017 and January 2018, exploring their characteristics and asking for evaluation of the course. The obstacles for implementing LLS in their centers have been assessed. RESULTS: Sixty-four surgeons (53.8%) responded to the survey; 42 (65.6%) were employed at a university hospital; and 39 (60.9%) were in the first decade of their practice as a consultant surgeon. Forty-three (67.2%) surgeons reported an increased percentage of LLS cases afterward. Training on Thiel cadavers was considered superior (49.2%) to other training options including proctoring in the operating room (34.9%), virtual reality (6.3%), video training (4.8%) and practicing on pigs (4.8%). Obstacles identified contained inadequate training, patient's referral pattern, financial issues, lack of dedicated surgical team and time constrains. CONCLUSIONS: This survey revealed that a structured short-time program incorporating interactive discussion, live operations and hands-on training on human bodies under proctorship may enhance efficient training in laparoscopic liver surgery. In a step forward for upcoming courses, the importance of team building has to be addressed.

Rectal lymphoma: report of a rare case and review of literature.

Colorectal lymphoma is an extremely rare disease, representing less than 0.5% of all primary colorectal neoplasms. The disease is usually diagnosed in the advanced stages because of its primary non-specific symptoms. The most common involved site is cecum followed by rectum and ascending colon. Diffuse large B-cell lymphoma is a more frequent subtype. Although surgical resection is often technically feasible, optimal therapy for a colorectal lymphoma, especially rectal lymphoma, has not yet been identified. The authors describe a patient with the primary rectal lymphoma, high-grade features and complete response to chemotherapy.

Delayed colonic perforation following stent placement for colorectal obstruction: a description of two cases with stent palliation.

Bowel stent insertion has a variety of complications one major of which is colonic perforation. The purpose of this article is to reveal two cases with delayed colonic perforation after stent placement to relieve bowel obstruction caused by rectal cancer. The first patient was a 55 year-old man who was a candidate for stent placement to avoid palliative surgery and relieve his bowel obstruction. Although the procedure resulted in complete relief of patient symptoms, but he returned with signs of peritonitis 10 days after the stent placement. A perforation was found at rectosigmoid junction on laparotomy. The second patient was a 60 year-old man who underwent a successful stent placement and returned 3 months later with a complaint of abdominal pain that showed up to be due to a rectal perforation on investigations. In conclusion, bowel perforation following stent placement can be a major complication, so close follow-up is necessary to detect it as soon as possible and prevent it from becoming an irreparable complication.

Management of treadmill hand injuries using soft tissue distraction.

BACKGROUND: In the modern day cities, home treadmill usage is increasing. Toddlers are prone to a special injury by the treadmill, during workout the toddler tries to get on the belt and the roller action pulls the fingers under the belt and get caught between the belt and a metal rod under the machine and the belt scrapes the fingers. If untreated some of these injuries will lead to flexion contracture. The usual treatment is release of contracture and skin grafting, however, graft discoloration and recurrence of contracture are the complications of this method and the patients usually seek treatment for the brown discoloration of the grafts at a later age. OBJECTIVES: In this study we assess the results of Z-plasty in combination with soft tissue distraction without skin grafting with long term usage of splint as an alternative treatment for these patients. MATERIALS AND METHODS: In this retrograde descriptive cross-sectional study, we evaluated the patients presented with treadmill hand injuries between the years 2006 and 2011. Demographic data including age and sex in addition to other information including location of trauma, severity of trauma, time elapsed between the trauma and treatment, type of treatment including wound care and surgical method and treatment outcomes were assessed. RESULTS: A total of 8 patients (3 girls and 5 boys) following finger treadmill injury were assessed. 15 fingers in 7 patients had volar injury. The middle finger was the most commonly injured finger. In all patients a minimum of 2 fingers were injured and in just 1 patient 3 fingers were injured. In long-term follow-up all the patients had acceptable volar skin and complete ROM of the fingers. CONCLUSIONS: Due to discoloration of the skin graft and recurrence of contracture following skin graft as the sole treatment for the injury, application of Z-plasty with soft tissue distraction and long term splints seems to be a proper alternative treatment for these patients.

Necrotizing fasciitis of the upper extremity, case report and review of the literature.

ABSTRACT: Necrotizing fasciitis is a rare, life-threatening infection most commonly seen in patients with diabetes mellitus, intravenous drug abuse, and immunocompromised conditions. The extremities are the primary sites of involvement in as many as two thirds of the cases. In a significant proportion of patients, the extremities are involved as a result of trauma, needle puncture or extravasation of drugs. The infection is usually polymicrobial. Treatment involves broad-spectrum antibiotics and multiple surgical debridements or amputation. We present a patient with necrotizing fasciitis of the upper limb and present our experience with this often lethal condition.