A DNA methylation atlas of normal human cell types.

DNA methylation is a fundamental epigenetic mark that governs gene expression and chromatin organization, thus providing a window into cellular identity and developmental processes1. Current datasets typically include only a fraction of methylation sites and are often based either on cell lines that underwent massive changes in culture or on tissues containing unspecified mixtures of cells2-5. Here we describe a human methylome atlas, based on deep whole-genome bisulfite sequencing, allowing fragment-level analysis across thousands of unique markers for 39 cell types sorted from 205 healthy tissue samples. Replicates of the same cell type are more than 99.5% identical, demonstrating the robustness of cell identity programmes to environmental perturbation. Unsupervised clustering of the atlas recapitulates key elements of tissue ontogeny and identifies methylation patterns retained since embryonic development. Loci uniquely unmethylated in an individual cell type often reside in transcriptional enhancers and contain DNA binding sites for tissue-specific transcriptional regulators. Uniquely hypermethylated loci are rare and are enriched for CpG islands, Polycomb targets and CTCF binding sites, suggesting a new role in shaping cell-type-specific chromatin looping. The atlas provides an essential resource for study of gene regulation and disease-associated genetic variants, and a wealth of potential tissue-specific biomarkers for use in liquid biopsies.

Exploring the Efficacy of the Paula Method of Muscle Exercises in Managing Low Anterior Resection Syndrome Using an Integrative Approach: A Preliminary Study.

Background: Low anterior resection syndrome (LARS) is a post-proctectomy consequence characterized by variable and unpredictable bowel function, including clustering, urgency, and incontinence, which significantly impacts the quality of life. Currently, there is no established gold-standard therapy for LARS. Primary Study Objective: This study aimed to evaluate the effectiveness of the Paula method of exercise as part of an integrative treatment approach for patients with LARS. Design: This preliminary study utilized a single-arm pretest-posttest design. Setting: The study was conducted at a tertiary care medical center. Participants: Five patients diagnosed with LARS completed the study. Intervention: Participants underwent twelve weeks of individualized Paula method exercise sessions. Two questionnaires were employed to assess the severity of LARS and quality of life. Primary Outcome Measures: (1) Low Anterior Resection Syndrome (LARS) Score; (2) Memorial Sloan Kettering Cancer Bowel Function Instrument (MSK-BFI); (3) Global Quality-of-Life (QOLS) Score . Results: All participants completing the 12-week Paula exercise regimen reported no difficulty in engaging with the exercises. Statistically significant improvements were observed in both the LARS score and MSK-BFI (P = .039 and P = .043, respectively, Wilcoxon Rank Sum test). While there were improvements in the global quality-of-life score and functional scales of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, these improvements did not reach statistical significance. Conclusions: This preliminary study suggests that patients with LARS can successfully complete a 12-week exercise program using the Paula method, resulting in improved LARS scores. However, further investigation through larger, multicenter, randomized controlled trials is necessary to establish the efficacy of these exercises as a treatment for LARS.

Existing Scores Fail to Predict Bowel Ischemia in Patients With Adhesive Small Bowel Obstruction.

INTRODUCTION: Early recognition of bowel ischemia is critical in patients suffering from acute adhesive small bowel obstruction (ASBO). Recent studies attempted to propose a score combining clinical and radiological factors to predict the risk of bowel ischemia in patients with ASBO. This study aimed to compare and validate the existing clinical scores with a cohort of surgical patients. METHODS: We conducted a retrospective study including all ASBO cases admitted to our institution between January 1, 2005 and December 31, 2019. Based on three existing clinical scores, we calculated the risk of bowel ischemia for each patient. We then divided the cohort into groups based on the risk for bowel ischemia. For each risk-based category, the proportion of patients who underwent surgical resection and were found to have evidence of ischemic bowel was calculated. RESULTS: A total of 160 patients presenting with 217 episodes of acute ASBO were included. One hundred seventy-one (78.8%) cases were managed nonoperatively while 46 cases (21.2%) required surgery. Sixteen patients (7.3%) were eventually found to have ischemic bowel while 13 required small bowel resection (5.9%). All three clinical scores showed correlation between the calculated risk of ischemia and the intraoperative finding of ischemia. However, all three scores overestimated ischemia rates in the high-risk groups, yielding a PPV of 8.3%-28.5% and a NPV of 93.3%-94.7%. CONCLUSIONS: Current clinical scores for predicting bowel ischemia in patients with ASBO are of high value in ruling out ischemia, yet are of extremely low sensitivity, warranting an overly aggressive and unnecessary surgical approach.

Higher Rates of Complicated Appendicitis During the COVID-19 Pandemic: A Year-to-Year Analysis.

INTRODUCTION: The COVID-19 pandemic impacted presentation, management strategies, and patient outcomes of numerous medical conditions. The aim of this study is to perform a year-to-year comparison of clinical outcomes of patients with acute appendicitis (AA) before and during the pandemic. METHODS: Patients treated for AA during the initial 12-mo period of the pandemic at our institute were compared to those treated for AA during the 12-mo period before. Clinical and laboratory parameters, treatment strategies, intraoperative findings, pathology reports, and postoperative outcomes were compared. RESULTS: During the study period, 541 patients presented with AA. The median (interquartile range) age was 28 (21-40) y and 292 (54%) were males. 262 (48%) patients presented during the pre-COVID-19 period, while 279 patients (52%) presented during the COVID 19 pandemic. The groups were comparable for baseline clinical data and imaging results upon index admission. There was no significant difference in rate of nonoperative treatment between the Pre-COVID-19 and During-COVID-19 eras (51% versus 53%, P = 0.6) as well as the success rate of such treatment (95.4% versus 96.4%, P = 0.3). Significantly more patients presented with a periappendicular abscess during COVID-19 (4.6% versus 1.1%, P = 0.01) and median (interquartile range) operative time was significantly longer (78 (61-90) versus 32.5 (27-45) min, P < 0.001). Pathology reports revealed a higher rate of perforated appendicitis during COVID-19 (27.4% versus 10.2%, P < 0.001). CONCLUSIONS: Patients with AA present with higher rates of perforated and complicated appendicitis during the COVID-19 pandemic. The success rates of nonoperative management in selected patients with noncomplicated AA did not change during the pandemic and is a safe, feasible, option.

A patient tailored approach to the surgical treatment of hemorrhoids leads to equal satisfaction following hemorrhoidectomy, stapled hemorrhoidopexy or a combination of both.

PURPOSE: Up to 20% of patients suffering from symptomatic hemorrhoids will require surgery. Excisional hemorrhoidectomy (EH) and stapled hemorrhoidopexy (SH) are both standard and safe procedures. While SH has a short-term advantage of faster recovery and lower postoperative pain, its long-term efficacy is debatable. This study aims to compare the outcomes of EH, SH, and a combined procedure of both. METHODS: A retrospective study compared the outcomes of patients treated surgically for hemorrhoids over a 5-year period. Eligible patients were asked by phone to complete a questionnaire evaluating recurrent symptoms, fecal incontinence, satisfaction, and self-assessed improvement in quality of life (QOL). RESULTS: This study included 362 patients, of whom 215 underwent SH, 99 underwent EH, and 48 underwent a combined procedure. No statistically significant differences were found between groups regarding complications, symptoms recurrence, or fecal incontinence. Combined procedure patients had significantly higher self-assessed improvement in QOL (P=0.04). CONCLUSION: In patients with symptomatic hemorrhoids, a tailored approach to symptomatic hemorrhoids is associated with high satisfaction rates and self-assessed improvement in QOL.

Minimally Invasive Parathyroidectomy: Can Intraoperative Parathyroid Hormone Monitoring be Omitted?

BACKGROUND: Intraoperative PTH (ioPTH) monitoring has become widely accepted in the era of minimally invasive parathyroidectomy (MIP). The purpose of this study was to evaluate the need for ioPTH during parathyroidectomy in patients with positive preoperative imaging. METHODS: The charts of patients who underwent parathyroidectomy at three tertiary centers between the years 2012 and 2021 were retrospectively reviewed. Patients were defined as MIP candidates with either concordant preoperative imaging or a single positive imaging. Patients with negative or discordant imaging, concomitant thyroidectomy, or previous neck surgery were excluded. RESULTS: Of a total of 1013 patients who underwent parathyroidectomy, 535 (52.8%) were defined as MIP candidates and were included in the statistical analysis. Surgical success was achieved in all patients. A single adenoma that corresponded to the preoperative imaging was identified and resected in 517 (93.8%) patients. In only 18 (3.3%) patients, the ioPTH correctly changed the operative management where additional pathologic glands were identified and excised. Patients with additional lesions were significantly more likely to have decreased index adenoma size as indicated either by preoperative imaging or by intraoperative findings (15.5 ± 6.6 vs. 8.3 ± 2.5 mm, p < 0.001). None of the patients with an adenoma size greater than 13 mm had an additional pathologic gland. CONCLUSIONS: Our findings suggest that the routine use of ioPTH in MIP candidates may be omitted in patients with an index adenoma greater than 13 mm, even with only a single positive preoperative imaging study, without compromising surgical success.

Composite Criteria for Non-Operative Management of Acute Non-Complicated Appendicitis Result in Low Failure Rates.

BACKGROUND: The aim of this study is to investigate the outcomes of conservative management of non-complicated acute appendicitis (AA) using our unique institutional protocol, and to compare between these and the outcomes of operative management. METHODS: Patients admitted to our institution between March 2016 and October 2019 with non-complicated AA were grouped according to their initial management: non-operative versus surgical. Our unique protocol for non-operative management includes: pain < 3 days; afebrile upon admission; non-gravid; WBC <15,000 (× 109/L); CRP < 5 mg/dl; appendix diameter < 1 cm; no appendicolith on imaging; no prior episode of AA; no history of Inflammatory Bowel Disease; no evidence of peritonitis on physical examination. The primary outcome measured was failure of non-surgical management during the index admission. Secondary outcomes included recurrence rate, readmissions, complications, length of antibiotic treatment and length of stay (LOS). RESULTS: A total of 695 patients were included, 436 in the operative group and 259 in the non-surgical treatment group. The mean follow-up time was 1004.9 ± 205.7 days. Patients initially treated conservatively rarely required surgery during their index admission (6.9%). Recurrence rate was 19.1% after a mean follow up of 33.4 months. The overall failure rate of conservative management was documented in 20.8% of the patients. The complication rate was higher in those treated with upfront surgery (1.6% vs. 0.4%, p < 0.001). The overall LOS was not statistically different between the groups. CONCLUSIONS: Our composite protocol for non-surgical management of non-complicated AA results in a low failure rate. A well calculated patient treatment allocation in non-complicated AA can advocate for wide-spread use of the conservative approach.

Ultrasonographic features can predict outcome of conservative management of acute appendicitis in children.

PURPOSE: To determine whether specific ultrasonographic features can predict failure of conservative treatment of acute appendicitis. METHODS: A 2-year retrospective study was conducted on children admitted with acute appendicitis. Those with uncomplicated appendicitis diagnosed solely by ultrasound, and treated conservatively, were followed 18-24 m to assess treatment outcome. Management was considered successful if recurrent acute appendicitis was not observed during follow-up. Appendix diameter, wall thickness, presence of mucosal ulceration, hyperechogenic fat, free fluid, and lymph nodes were evaluated as potential discriminatory ultrasonographic predictors. T-tests, chi-square, sensitivity, specificity, and odds ratios were calculated. RESULTS: Out of 556 consecutive patients that were admitted with acute appendicitis, 180 (32%) managed conservatively. One hundred eleven (62%) imaged by US only. Ninety-two out of 111 (83%) were followed 18-24 m to assess treatment outcome, and 19/111 (17%) were lost to follow-up. Conservative management was successful in 72/92 (78.2%), with treatment failure in 20/92 (21.8%) (5/92 (5.4%) with recurrent acute appendicitis and 15/92 (16.3%) underwent appendectomy). Of the ultrasonographic features studied, mucosal ulceration demonstrated statistically significant predictive value. Fifteen out of 20 (75%) treatment failures had mucosal ulceration, compared to 21/72 (29.2%) of the patients with successful treatment (p < 0.001). This yielded a positive odds ratio of 7.3 (2.3-22.6, 95% CI), 70.8% (58.9-80.9, 95% CI) specificity, and 75% (50.9-91.3, 95% CI) sensitivity. Positive predictive value was 41.6% (31.5-52.5, 95% CI) while intact mucosa had negative predictive value of 91% (82.4-95.6, 95% CI) for conservative management success. CONCLUSION: The presence or absence of appendiceal mucosal ulceration at ultrasound can predict conservative management outcome in the setting of acute appendicitis, potentially improving pediatric patient selection for conservative management.

Elective minimally invasive surgery for sigmoid diverticulitis: operative outcomes of patients with complicated versus uncomplicated disease.

AIM: The aim of this work was to compare the results of elective minimally invasive surgery between patients with complicated sigmoid diverticulitis and those with uncomplicated disease. METHOD: An institutional review board-approved database was searched for all consecutive patients who underwent elective minimally invasive surgery, including laparoscopic, hand-assisted and robotic sigmoidectomy, for diverticulitis between 2010 and 2017; they were classified according to the modified Hinchey classification as having complicated (abscess, fistula, stricture, obstruction, bleeding or previous perforation) versus uncomplicated disease. Data recorded included baseline demographics, indications for surgery, operative details and complications. RESULTS: Three hundred and twenty-five patients underwent elective sigmoidectomy for complicated (n = 105) and uncomplicated (n = 220) diverticulitis. Surgical indications for complicated disease were abscess (n = 74), stricture (n = 14), fistula (n = 28) and bleeding (n = 7). The two groups were statistically comparable for age, gender, body mass index and American Society of Anesthesiologists score. Patients with complicated disease had higher rates of concomitant loop ileostomy creation (9.5% vs. 0.9%, p < 0.001) and synchronous resections (9.5% vs. 2.7%, p = 0.01), higher volumes of blood loss (177 ± 140 vs. 125 ± 92 ml, p < 0.001), longer length of stay (5.6 ± 3 vs. 4.8 ± 2 days, p = 0.04) and longer operating time (218.2 ± 59 vs. 185.8 ± 63 min, p < 0.001). There were no significant differences in anastomotic leakage (3% vs. 1%, p = 0.3), conversion to laparotomy (4.8% vs. 2.3%, p = 0.3) or overall complications (36% vs. 25.9%, p = 0.06) for complicated versus uncomplicated disease, respectively. CONCLUSION: Minimally invasive surgery for complicated diverticulitis resulted in higher rates of construction of proximal ileostomy and synchronous resections and longer operating times and length of hospital stay. Otherwise, it has outcomes that are not significantly different from the results recorded in patients with uncomplicated disease.

How accurate is preoperative colonoscopic localization of colonic neoplasia?

INTRODUCTION: Preoperative colonoscopic localization for resection of colonic neoplasia, with or without tattooing for guidance, has been extensively used with variable accuracy. Difficulty in intraoperative identification of the lesion may lead to resection of an incorrect segment or to a more extensive resection than originally planned. The aim of this study was to evaluate the accuracy of preoperative colonoscopy in determining the site of the lesion. METHODS: A prospectively collected IRB-approved institutional database was retrospectively queried for all consecutive patients who underwent an elective colon resection for neoplasia between 2013 and 2016. Excluded were patients without preoperative colonoscopy reports available for comparison or who underwent emergency surgery. Surgical plan based on preoperative colonoscopic localization with or without tattooing was compared to the final surgery and pathology reports. RESULTS: 203 patients were included [mean age 68 (35-92) years; 102 males (50.2%)]. Preoperative colonoscopy was inaccurate in 16.7% (34 patients) leading to a change in the surgical plan. Patients with transverse or distal lesions were more likely to have a change in final surgical management compared to proximal sided lesions (29.7% vs. 3.9%, respectively; p < 0.001). Only 3.8% of the tattooed lesions could not be identified during surgery. Additional intraoperative colonoscopy was needed in 11 patients (5.5%) to verify exact lesion location. Average length of the resected segment was longer in patients who required a change in surgical plan (26.44 cm vs. 22.47 cm; p = 0.02). CONCLUSION: Inaccurate preoperative colonoscopic localization led to a change in surgical management in 16.7% of cases, especially in transverse or left sided lesions. Surgeons should consider these findings when planning colonic resections.

A comparison between one- and two-stage revisional gastric bypass.

BACKGROUND: The safety of performing a one-stage revision from laparoscopic adjustable gastric banding (LAGB) to laparoscopic Roux-en-Y gastric bypass (LRYGB) has been questioned. The objective of this study was to compare safety and outcomes of one-stage versus two-stage revisional LRYGB performed after failed LAGB. METHODS: A retrospective analysis of all patients undergoing revisional LRYGB after failed LAGB between January 2007 and March 2017 was performed. Patients undergoing one- and two-stage revisions were compared. The primary outcome assessed was the early complication rate, while secondary outcomes included late complications, weight loss, and improvement of comorbidities. RESULTS: During the study period, 161 revisional LRYGB's were performed, including 121 one-stage and 40 two-stage procedures. Baseline demographic data, BMI and presence of comorbidities were similar between the groups. In patients undergoing a two-stage procedure, band slippage, port infection, and erosion were more commonly cited as indications for revision. Similar early complication rates were demonstrated between the groups. However, late complications were more common in the two-stage group (20.0% vs. 7.4%, P = 0.03), including higher rates of gastro-gastric fistula (5.0% vs. 0%, P = 0.01) and anemia (10.0% vs. 1.1%, P = 0.02). Three-fourths of the cohort had a follow-up of more than 6 months, and the two groups demonstrated similar weight loss results and improvement/resolution of comorbidities. CONCLUSION: The performance of one-stage revisional LRYGB after failed LAGB seems to be a safe procedure, with noninferior outcomes when compared to a two-stage revisional procedure. It is a valid option, except in cases of mechanical and infectious band complications.

Long-term outcomes of sigmoid diverticulitis: a single-center experience.

BACKGROUND: During the last decade, guidelines for the treatment of sigmoid diverticulitis have dramatically changed. The aim of this study is to report the long-term outcomes of patients treated for diverticulitis at a nonspecialized single center. MATERIALS AND METHODS: After obtaining institutional review board approval, medical records of all patients admitted to our institution with the diagnosis of sigmoid diverticulitis between 1998 and 2008 were reviewed. A follow-up of at least 5 years was required. RESULTS: During the study period, 266 patients were admitted to our hospital due to sigmoid diverticulitis with a mean follow-up period of 120 ± 2 months. Of the entire cohort, 249 patients (93.5%) were treated conservatively and 17 (6.5%) patients required emergent surgery on initial presentation. Patients treated conservatively (n = 249) encountered a median of two recurrent episodes (range 0-4). During follow-up, none of these patients required emergent surgery, and 27 patients (11%) underwent elective surgery for recurrent episodes (n = 24), chronic smoldering disease (n = 2), and fistula (n = 1). Minor and major complication rates after elective surgery were 18.5% and 30%, respectively. Specifically, four patients (15%) suffered an anastomotic leak (AL). Late complications after elective surgery occurred in 33% of patients including incisional hernias (11%), bowel obstruction (3.7%), anastomotic stenosis (3.7%), and recurrent diverticulitis (15%). CONCLUSIONS: Patients treated conservatively during their index admission for sigmoid diverticulitis do not require emergent surgery during long-term follow-up and the majority of patients (89%) do not require elective surgery. Elective sigmoidectomy at nonspecialized centers may result in high rates of recurrent diverticulitis (15%) and anastomotic leak (15%).

Outcomes of interval appendectomy in comparison with appendectomy for acute appendicitis.

BACKGROUND: Traditionally, patients treated conservatively for periappendiceal abscess or phlegmon would subsequently undergo interval appendectomy (IA); however, recent evidence has shed doubt on the necessity of this procedure. This study aimed to assess the outcomes of patients who underwent IA, in comparison with those operated acutely for appendicitis. MATERIALS AND METHODS: A retrospective analysis identified patients who underwent IA between 2000 and 2016. Their course and outcomes were compared with those of our previously published cohort of patients who underwent appendectomy for acute appendicitis. RESULTS: During the study period, 106 patients underwent IA. Their mean age was 39.7 ± 16.2 y, and 60.4% were females. In their index admission, 75.5% presented with abscesses. IA was performed successfully in all patients, and no patient required colectomy. Pathology demonstrated neoplastic lesions in 6/106, but only one was malignant. IA patients were compared with a cohort of 1649 acute appendectomy patients. This group was significantly younger (33.7 ± 13.3 y). Operation time was comparable between the groups (46.0 ± 26.2 versus 42.7 ± 20.9 min, respectively, P = 0.33). In the IA group, significantly more laparoscopic operations were performed (100% versus 93.9%), but with a higher conversion rate to open (1.9% versus 0.13%, P < 0.001). Although the overall complication rate was comparable, more intraoperative complications (2.8% versus 0.3%, P < 0.001) and deep/organ-space surgical site infections (surgical site infection; 4.7% versus 1.2%, P = 0.003) were reported in the IA group. CONCLUSIONS: IA can be a challenging procedure and should not be performed on a routine basis. However, neoplasia must be actively ruled out, particularly in the older age group.

Delayed Laparoscopic Cholecystectomy for Acute Calculous Cholecystitis: Is it Time for a Change?

BACKGROUND: Our aim was to evaluate the advantages and limitations of delayed laparoscopic cholecystectomy (LC) in a tertiary center. MATERIALS AND METHODS: A retrospective analysis of all patients admitted to our institution with acute calculous cholecystitis (ACC) between January 2003 and December of 2012 was performed. Data collected included patient demographics and comorbidities, presenting symptoms, laboratory findings, imaging results, length of stay (LOS), time to surgery, and surgical complications. RESULTS: A total of 1078 patients were admitted with ACC. There were 593 females (55%), and the mean age was 57 ± 0.6 years. Mean LOS at initial admission, re-admission until surgery, and following surgery was 7.9 ± 0.2, 1.5 ± 0.1, and 3.4 ± 0.2 days, respectively. Percutaneous cholecystostomy (PC) tube was inserted in 24% of the patients. Only 640 (59%) patients eventually underwent LC. Mean time to surgery was 97 ± 9.8 days, and 16.4% of patients were readmitted in this time period resulting in a mean total LOS of 10.6 ± 0.2 days. Conversion rate to open surgery was 5.8% and bile duct injury occurred in 1.1%. Postoperative complications occurred in 9.8% of the patients, and 30-day mortality was 0.6%. Patients with more severe inflammation according to Tokyo Criteria grade were more likely to undergo PC, were more likely to be readmitted while waiting for LC, and also had more postoperative complications. CONCLUSIONS: Delayed LC is associated with significant loss of follow-up, long LOS, and higher than expected use of PC. Conversion rates are lower than in the literature while rates of bile duct injury and mortality are comparable. We believe these data as well as the available literature are sufficient to change our hospital policy regarding the surgical treatment of ACC from delayed to early same admission surgery in appropriate cases.

Prospective validation of a surgical complications grading system in a cohort of 2114 patients.

BACKGROUND: We recently reported a grading system for surgical complications. This system proved to have a high sensitivity for recording minor but meaningful complications prolonging hospital stay in patients after colorectal surgery. We aimed to prospectively validate the complication grading system in a general surgery department over 1 year. METHODS: All surgical procedures and related complications were prospectively recorded between January 1st and December 31st, 2009. Surgical complications were graded on a severity scale of 1-5. The system classifies short-term outcome by grade emphasizing intensity of therapy required for treatment of the defined complication. RESULTS: During the study period, 2114 patients underwent surgery. Elective and oncological surgeries were performed in 1606 (76%) and 465 (22%) patients, respectively. There were 422 surgical complications in 304 (14%) patients (Grade 1/2: 203 [67%]; Grade 3/4: 90 [29%]; Grade 5: 11 [4%]). Median length of stay correlated significantly with complication severity: 2.3 d for no complication, 6.2 and 11.8 d for Grades 1/2 and 3/4, respectively (P < 0.001). Older age (OR 2.75, P < 0.001), comorbidities (OR 1.44, P = 0.02), American Society of Anesthesiology score >2 (OR 2.07, P < 0.001), contamination Grade (OR 1.85, P = 0.001), oncological (OR 2.82, P < 0.001), open (OR 1.22, P = 0.03), prolonged >120 min (OR 2.08, P < 0.001), and emergency surgery (OR 1.42, P = 0.02) independently predicted postoperative complications. CONCLUSIONS: This system of grading surgical complications permits standardized reporting of surgical morbidity according to the severity of impact. Prospective validation of this system supports its use in a general surgery setting as a tool for surgical outcome assessment and quality assurance.

Similar Rates of Symptomatic Marginal Ulcers After One-Anastomosis-Gastric Bypass Compared to Roux-en-Y Gastric Bypass.

PURPOSE: One-anastomosis-gastric-bypass (OAGB) has become a common bariatric procedure worldwide. Marginal ulcers (MU) are a significant non-immediate complication of gastric bypass surgeries. There seems to be concern among surgeons that MU are more common after OAGB compared with Roux-en-Y gastric bypass (RYGB) due to the constant and extensive exposure of the anastomosis to bile. The aim of this study was to compare the incidence, presentation, and management of MU between the two surgeries. MATERIALS AND METHODS: A retrospective study of prospectively collected data was performed to include all consecutive patients between 2010 and 2020, who underwent elective OAGB or RYGB at our institution. Patients diagnosed with symptomatic MU were identified. Factors associated with this complication were assessed and compared between the two surgeries. RESULTS: Symptomatic MU were identified in 23/372 OAGB patients (6.2%) and 35/491 RYGB patients (7.1%) (p = 0.58). Time to ulcer diagnosis was shorter in OAGB patients (12 ± 11 vs. 22 ± 17 months, p < 0.01). Epigastric pain was the common symptom (78% OAGB vs. 88.5% RYGB, p = 0.7) and approximately 15% of ulcers presented with perforation upon admission (17% vs.11.4%, p = 0.7). Re-operation was required in 5/23 OAGB (21.7%) and 6/36 RYGB (17%) patients (p = 0.11) while the rest of the patients were managed non-operatively. CONCLUSIONS: The risk of developing a marginal ulcer is similar between patients who underwent OAGB and RYGB. Patients diagnosed with MU following OAGB tend to present earlier; however, the clinical presentation is similar to RYGB patients. The management of this serious complication seems to be associated with acceptable outcomes with comparable operative and non-operative approaches.

Incidence and Risk Factors for Low Anterior Resection Syndrome following Trans-Anal Total Mesorectal Excision.

BACKGROUND: Trans-anal total mesorectal excision (Ta-TME) is a novel approach for the resection of rectal cancer. Low anterior resection syndrome (LARS) is a frequent functional disorder that might follow restorative proctectomy. Data regarding bowel function after Ta-TME are scarce. The aim of this study was to evaluate the incidence and risk factors for the development of LARS following Ta-TME. METHODS: A prospectively maintained database of all patients who underwent Ta-TME for rectal cancer at our institution was reviewed. All patients who were operated on from January 2018 to December 2021 were evaluated. The LARS score questionnaire was used via telephone interviews. Incidence, severity and risk factors for LARS were evaluated. RESULTS: Eighty-five patients underwent Ta-TME for rectal cancer between January 2018 and December 2021. Thirty-five patients were excluded due to ostomy status, death, local disease recurrence, ileal pouch or lack of compliance. Fifty patients were included in the analysis. LARS was diagnosed in 76% of patients. Anastomosis distance from dentate line was identified as a risk factor for LARS via multivariate analysis (p = 0.042). Neo-adjuvant therapy, hand sewn anastomosis and anastomotic leak did not increase the risk of LARS. CONCLUSION: LARS is a frequent condition following ta-TME, as it is used for other approaches to low anterior resection. Anastomosis distance from dentate line is an independent risk factor for LARS. In this study neo-adjuvant therapy, hand sewn anastomosis and anastomotic leak did not increase the risk of LARS. Further studies with longer follow-up times are required to better understand the functional outcomes following Ta-TME.

Comparison of pediatric appendectomy outcomes between pediatric surgeons and general surgery residents.

BACKGROUND: Appendectomy is the most common urgent procedure in children, and surgical outcomes may be affected by the surgeon's experience. This study's aim is to compare appendectomy outcomes performed by pediatric surgeons (PSs) and general surgery residents (GSRs). MATERIALS AND METHODS: A retrospective review of all patients younger than 16y treated for appendicitis at two different campuses of the same institution during the years 2008-2009 was performed. Appendectomies were performed by PS in one campus and GSR in the other. Primary end points included postoperative morbidity and hospital length of stay. RESULTS: During the study period, 246 (61%) patients were operated by senior GSR (postgraduate year 5-7) versus 157 (39%) patients by PS. There was no significant difference in patients' characteristics at presentation to the emergency room and the rate of appendeceal perforation (11% versus 15%, P=0.32), and noninfectious appendicitis (5% versus 5% P=0.78) also was similar. Laparoscopic surgery was performed more commonly by GSR (16% versus 9%, P=0.02) with shorter operating time (54±1.5 versus 60±2.1, P=0.01). Interestingly, the emergency room to operating room time was shorter for GSR group (419±14 versus 529±24min, P<0.001). The hospital length of stay was shorter for the GSR group (4.0±0.2 versus 4.5±0.2, P=0.03), and broad-spectrum antibiotics were used less commonly (20% versus 53%, P<0.0001) and so was home antibiotics continuation (13% versus 30%, P<0.0001). Nevertheless, postoperative complication rate was similar (5% versus 7%, P=0.29) and so was the rate of readmissions (2% versus 5%, P=0.52). CONCLUSIONS: The results of this study suggest that the presence of a PS does not affect the outcomes of appendectomies.

Differentiating benign from malignant thyroid nodules using micro ribonucleic acid amplification in residual cells obtained by fine needle aspiration biopsy.

BACKGROUND: Fine needle aspiration biopsy (FNAB) is the most commonly used diagnostic tool to differentiate benign from malignant thyroid nodules. Nevertheless, some FNAB cytology results are not definite. In such cases diagnostic thyroid lobectomy is performed with malignancy rate on final histopathology ranging at 15%-75%. The aim of this study was to improve on the accuracy of FNAB-based cytology by amplification of microRNAs (micro ribonucleic acids [miRs]) from the residual cells left in the FNAB needle after submission for cytology. METHODS: Residual cells were collected from the needle cup after FNAB cytology of 77 consecutive patients with thyroid nodules. miR-enriched RNA was extracted for all patients with cytology showing either follicular lesion or suspicion for malignancy (n=11). The expression of miR-21, -31, -146b, -187, -221, and -222 was determined using real-time polymerase chain reaction. Results were compared with final surgical histopathology. RESULTS: RNA was successfully extracted from all FNAB specimens. Five patients had FNAB cytology suspicious for malignancy. The miR panel was positive in all five (100%). Six patients had follicular lesions on FNAB. The miR panel was positive in three of four patients (75%) with confirmed malignancy and was negative in two of two (0%) patients with benign pathology results. This corresponded to a specificity of 100%, sensitivity of 88%, and accuracy of 90%. CONCLUSIONS: RNA extraction from FNAB residual cells is feasible, and a miR panel amplified from the extracted RNA seems like a promising diagnostic tool in this limited number of patients.

A Comparison of Outcomes in Medullary Thyroid Carcinoma Patients With and Without a Preoperative Diagnosis: A Multicenter Retrospective Cohort Study.

Background: Cytological limitations pose a challenge to preoperative diagnosis of medullary thyroid carcinoma (MTC) and therefore, a significant subset of patients is only diagnosed postoperatively. The objective of this study was to investigate the impact of knowledge of a preoperative MTC diagnosis on disease management and outcomes. Methods: Multicenter, retrospective, cohort study of MTC patients treated in Israel from January 2000 to June 2021. We compared cohorts of patients according to the presence or absence of a preoperative MTC diagnosis. Results: Ninety-four patients with histologically confirmed MTC were included (mean age 56.2 ± 14.3 years, 43% males). Fifty-three patients (56%) had a preoperative MTC diagnosis (preop-Dx group), and 41 (44%) were confirmed only postoperatively (no-Dx group). The extent of surgical resection, including completion procedures, was as follows: total thyroidectomy in 83% versus 100% (p = 0.002), central lymph node dissection (LND) in 46% versus 98% (p < 0.001), ipsilateral lateral LND in 36% versus 79% (p < 0.001), and contralateral lateral LND in 17% versus 28% (NS), in the no-Dx versus the preop-Dx group, respectively. Pathology confirmed a smaller median tumor size of 16 ± 17.4 mm versus 23 ± 14.0 mm (p = 0.09), a higher proportion of micro-MTC (size ≤10 mm) 32% versus 15% (p = 0.03), and a higher rate of co-occurrence of follicular cell-derived carcinoma 24% versus 4% (p = 0.003), in the no-Dx compared to the preop-Dx group, respectively. The rates of extrathyroidal and extranodal tumor extension were not significantly different between the groups. At the last follow-up, the biochemical cure was attained in 55% [CI 0.38-0.71] compared to 64% [CI 0.50-0.77] of the no-Dx and the preop-Dx group, respectively (p = 0.41). After the exclusion of patients with micro-MTC, biochemical cure was more commonly achieved in the preop-Dx group (33% [CI 0.14-0.52] vs. 62% [CI 0.46-0.77], p = 0.04). Preop-Dx patients had improved overall survival compared to the no-Dx group (log-rank p = 0.04) over a median follow-up of 82 months (interquartile range [IQR] 30-153). Conclusions: Preoperatively, the diagnosis of MTC is often missed. An accurate preoperative diagnosis of MTC may enable guideline-concordant surgical treatment and ultimately contribute to an overall survival benefit in MTC patients.