Mirizzi Syndrome-The Past, Present, and Future

Mirizzi syndrome is a complication of gallstone disease caused by an impacted gallstone in the infundibulum of the gallbladder or within the cystic duct, causing chronic inflammation and extrinsic compression of the common hepatic duct or common bile duct. Eventually, mucosal ulceration occurs and progresses to cholecystobiliary fistulation. Numerous systems exist to classify Mirizzi syndrome, with the Csendes classification widely adopted. It describes five types of Mirizzi syndrome according to the presence of a cholecystobiliary fistula and its corresponding severity, and whether a cholecystoenteric fistula is present. The clinical presentation of Mirizzi syndrome is non-specific, and patients typically have a longstanding history of gallstones. It commonly presents with obstructive jaundice, and can mimic gallbladder, biliary, or pancreatic malignancy. Achieving a preoperative diagnosis guides surgical planning and improves treatment outcomes. However, a significant proportion of cases of Mirizzi syndrome are diagnosed intraoperatively, and the presence of dense adhesions and distorted anatomy at Calot's triangle increases the risk of bile duct injury. Cholecystectomy remains the mainstay of treatment for Mirizzi syndrome, and laparoscopic cholecystectomy is increasingly becoming a viable option, especially for less severe stages of cholecystobiliary fistula. Subtotal cholecystectomy is feasible if total cholecystectomy cannot be performed safely. Additional procedures may be required, such as common bile duct exploration, choledochoplasty, and bilioenteric anastomosis. Conclusions: There is currently no consensus for the management of Mirizzi syndrome, as the management options depend on the extent of surgical pathology and availability of surgical expertise. Multidisciplinary collaboration is important to achieve diagnostic accuracy and guide treatment planning to ensure good clinical outcomes.

Meta-analysis and systematic review: Prevalence, graft failure, mortality, and post-operative thrombosis in liver transplant recipients with pre-operative portal vein thrombosis

AIMS

This study seeks to evaluate the association between pre-transplant portal vein thrombosis (PVT) and overall survival, graft failure, waitlist mortality, and post-operative PVT after liver transplantation.

METHODS

A conventional pairwise meta-analysis between patients with and without pre-transplant PVT was conducted using hazard ratios or odds ratios where appropriate.

RESULTS

Prevalence of preoperative PVT was 11.6% (CI 9.70-13.7%). Pre-operative PVT was associated with increased overall mortality (HR 1.45, 95% CI 1.27-1.65) and graft loss (HR 1.58, 95% CI 1.34-1.85). In particular, grade 3 (HR 1.59, 95% CI 1.00-2.51) and 4 (HR 2.24, 95% CI 1.45-3.45) PVT significantly increased mortality, but not grade 1 or 2 PVT. Patients with PVT receiving living donor (HR 1.54, 95% CI 1.24-1.91) and deceased donor (HR 1.52, 95% CI 1.21-1.92) liver transplantation had increased mortality, with no significant difference between transplant types (P = .13). Furthermore, pre-transplant PVT was associated with higher occurrence of post-transplant PVT (OR 5.06, 95% CI 3.89-6.57). Waitlist mortality was not significantly increased in patients with pre-transplant PVT.

CONCLUSION

Graft failure, mortality, and post-operative PVT are more common in pre-transplant PVT patients, especially in grade 3 or 4 PVT. Prophylactic anticoagulation can be considered to reduce re-thrombosis and improve survival.

Endoscopic submucosal dissection versus endoscopic mucosal resection for rectal carcinoid tumor. A meta-analysis and meta-regression with single-arm analysis

OBJECTIVE

As there has been so far no consensus on the best endoscopic resection technique, a meta-analysis was conducted to compare the efficacy and safety of endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) for treating rectal carcinoid tumors.

METHODS

MEDLINE and EMBASE databases were searched for articles on the treatment of rectal carcinoid tumors using ESD vs EMR published up to October 2020 for outcomes including en bloc and complete resection, margin involvement, procedure time, requirement for additional surgery, bleeding, perforation and recurrence. Risk ratio and weighted mean differences were used for a DerSimonian and Laird random effects pairwise meta-analysis. Single-arm meta-analyses of proportions and random effects meta-regression analysis were also conducted.

RESULTS

Twenty-two studies involving 1360 rectal carcinoid tumors were included, in which 655 and 705 rectal carcinoid tumors were resected with ESD and EMR, respectively. The resection efficacy of ESD was comparable to that of EMR for tumors <10 mm. However, there were a significantly higher complete resection rate, and lower rates of vertical margin involvement and requirement for additional surgery using ESD than using EMR for tumors ≤20 mm. ESD had a longer procedure time and an increased likelihood of bleeding than EMR.

CONCLUSIONS

ESD is more effective in providing a curative treatment for rectal carcinoid tumors ≤20 mm in size as ESD can achieve a higher complete resection rate with lower vertical margin involvement than EMR. While they are suitable for treating rectal carcinoid tumors <10 mm as both techniques provide similar efficacy.

Preoperative concerns of patients undergoing general surgery

OBJECTIVES

This qualitative review aims to provide a clearer understanding of concerns general surgery (GS) patients face in the preoperative period.

METHODS

Medline, CINAHL, PsycINFO and Web of Science were searched for articles describing the preoperative concerns of GS patients. Qualitative and mixed method studies were included. Key quotes were extracted, coded, and thematically analyzed according to Thomas and Harden's methodology.

RESULTS

27 articles were included. Three main themes were generated: (1) lead-up to surgery, (2) postoperative recovery process and (3) standard of care. While waiting for surgery, patients were often shrouded with uncertainty and concerned themselves with the potential impacts of their disease and surgery on their wellbeing and recovery. Furthermore, patients' trust and confidence in Healthcare Professionals (HCPs) was compromised when standard of care was perceived to be deficient, resulting in doubts about HCPs' credibility and capabilities.

CONCLUSION

Patients' preoperative concerns often stem from the uncertainty and unfamiliarity surrounding surgery. To address this, a combination of effective preoperative education, individualised communication and involvement of social support should be considered.

PRACTICE IMPLICATIONS

Preoperative concerns can negatively impact patients and effective interventions will result in a better perioperative experience with fewer negative consequences arising from patients' fear and anxiety.

19 Colectomy Rate for Moderate to Severe Ulcerative Colitis with Biologics

Introduction

Biologics are recommended by both the ACG and ECCO community for the treatment of ulcerative colitis. Yet, current literature has yet to estimate the rate of colectomies after biologic therapy, and thus a pooled meta-analysis was conducted the rate of colectomies in 1month, 6 months, 1 year, 2years and five years after biologics.

Method

Medline and Embase were searched for articles examining biologics use in moderate to severe UC or acute severe UC (ASUC) from inception to 21st May 2020. Analysis of proportions were undertaken after a freeman-tukey double arcsine transformation.

Results

The pooled overall colectomy rates of ASUC and moderate to severe UC were 9% (CI: 4% - 14%) at one month, 18% (CI: 13% - 25%) at six months, 21% (CI:16% - 27%) at one year, 29% (CI:24% - 34%) at two years and 38% (CI:30% - 45%) at five years. Additionally, colectomy rates were consistently lower comparing between articles before and after 2010. At one-year, overall colectomy rate following infliximab use was at 25%, golimumab at 15%, vedolizumab at 14%, and adalimumab at 3%.

Conclusions

Colectomy rates in the era of biologics ranged from 8% to 38% and lower post-2010 showing significant improvement in management and supporting the utility of biologics in Ulcerative colitis management.

131 Concerns of The Unheard: A Qualitative Systematic Review on The Preoperative Concerns of General Surgery Patients

Aim

Method

CINAHL, Medline, PsycINFO, and Web of Science were searched, and articles related to patients’ preoperative concerns were included. Key quotes were extracted, coded, and thematically analyzed according to Thomas and Harden’s methodology.

Results

Three themes were generated from the 27 included articles; lead-up to surgery, the postoperative recovery process, and HCP care provision. Patients were uncertain and concerned about the impact the surgery or disease may have on them while they waited for their surgery to occur. Additionally, perceived inadequate provision of care by patients led to them doubting their HCPs’ ability, heightening their preoperative anxiety. Lastly, postoperative recovery processes were often unclear, leading to increased distress as patients wonder if they could recover from the disease and/or surgery.

Conclusions

Unresolved preoperative concerns increase patients’ anxiety and uncertainty, negatively affecting their postoperative recovery. A combination of individualized preoperative education and complementary therapy can be implemented by HCPs to alleviate these concerns, leading to better postoperative outcomes.

368 Perioperative Outcomes in Open versus Laparoscopic Surgery in Elderly Patients Undergoing Right Hemicolectomy

Introduction

With the global aging population, elderly patients are increasingly undergoing colorectal surgery. This study aims to evaluate postoperative outcomes in open (OS) and laparoscopic surgery (LS) for right hemicolectomy in elderly patients.

Method

We retrospectively reviewed patients aged 70 and above undergoing right hemicolectomy for malignancies at our institution. Additionally, Embase and Medline databases were reviewed, and comparative meta-analysis was conducted.

Results

84 patients were included in our cohort (OS = 34; LS = 50). No significant difference in anastomotic leak (AL) (OS = 4; LS = 2; p = 0.176), surgical site infection (SSI) (OS = 4; LS = 2; p = 0.216), and ileus (OS = 10; LS = 16; p = 0.801) was observed. LS was associated with decreased postoperative stay (p = 0.001). Additionally, LS had faster return of bowel function (ROBF) (p = 0.068) and resumption of diet (p = 0.147), albeit without significance. Overall survival (p = 0.062), and disease-free survival (p = 0.067) did not significantly differ between LS and OS.

Pooled analysis of 463 patients yielded no significant difference in AL (OR:1.15; 95%CI: 0.17-8.01; p = 0.89), SSI (OR:0.88; 95%CI: 0.44-1.76; p = 0.71), and ileus (OR:1.42; 95%CI: 0.69 – 2.92; p = 0.35). Postoperative stay (WMD:1.90 days; 95%CI: -1.81–5.61 days; p = 0.31), and ROBF (WMD:14.49 hours; 95%CI: -4.07–33.05 hours; p = 0.13) were shortened in LS, although without significance.

Conclusions

LS is associated with improved functional outcomes without an increased risk of postoperative morbidity or mortality.

20 Post-Operative Biologics and the Rate of Recurrence in Crohn’s Disease

Introduction

Post-operative recurrence after Crohn’s surgery poses a significant challenge to clinicians with an estimated of 70-90% recurrence rate. However, with the advent of biologics, reduction of recurrence after surgery has been observed in various landmark trials. Hence, we aim to quantify the rate of recurrence with post-operative biologics.

Method

Searches were done on Embase and Medline database for articles using biologics for post-operative management. A single arm meta-analysis with generalized linear mixed model and Clopper-Pearson method confidence interval was applied in the synthesis of the data on six months, one year, two year and five year.

Results

A total of 1,864 abstracts were identified, with a final total of 24 articles and 1042 patients were included in the meta-analysis. The one-year rate of recurrence for surgical, endoscopic and clinical was 3.08% (CI: 0.74% - 11.95%), 19.93% (15.81% - 24.81%) and 13.06% (CI: 8.18% - 18.92%) respectively. Correspondingly, the five-year recurrence 16.90% (CI: 9.57% - 28.11%), 84.21% (CI: 72.35% - 91.57%), 5.60% (CI: 9.92% -23.66%) respectively.

Conclusions

An observed reduction in surgical rates was reduced at five years with post-operative Crohn’s disease with biologics. Biologics therapy thus can be considered as a suitable alternative for reducing post-operative recurrence in individuals with higher risk.

189 Preliminary Results from an Innovative Surgical Research Group for Medical Students

Introduction

Learning research in medical school can be daunting and difficult with many lacking appropriate guidance. Particularly, research in surgery can be difficult with most clinicians tied to long hours from clinical duties, leaving medical students lost to learn the ropes for medical research.

Method

We started a surgical research group in January of 2020 under a shepherd sheep model. Shepards were senior medical students who had previous experience in research and were provided resources from consultants on statistics and research designs. Thereafter, each Shepard were paired with junior medical students (sheep) and a resident to provide clinical background. Research was then carried out small teams with minimal guidance from consultants.

Results

To date, the group has published 11 articles (median impact factor: 2.41, range: 1.89 - 3.42), 3 articles in revision and 9 articles in review.

Conclusions

We provide preliminary evidence of a successful model for building medical student research in surgery. While current analysis was limited to meta-analysis and systematic review due to the availability of data, current expansion is currently underway to expand to observational studies.

Is colonic lavage a suitable alternative for left-sided colonic emergencies?

BACKGROUND

The use of intra-operative colonic lavage (IOCL) with primary anastomosis remains controversial in the emergency left-sided large bowel pathologies, with alternatives including Hartmann’s procedure, manual decompression and subtotal colectomy.

AIM

To compare the peri-operative outcomes of IOCL to other procedures.

METHODS

Electronic databases were searched for articles employing IOCL from inception till July 13, 2020. Odds ratio and weighted mean differences (WMD) were estimated for dichotomous and continuous outcomes respectively. Single-arm meta-analysis was conducted using DerSimonian and Laird random effects.

RESULTS

Of 28 studies were included in this meta-analysis, involving 1142 undergoing IOCL, and 634 other interventions. IOCL leads to comparable rates of wound infection when compared to Hartmann’s procedure, and anastomotic leak and wound infection when compared to manual decompression. There was a decreased length of hospital stay (WMD = -7.750; 95%CI: -13.504 to -1.996; P = 0.008) compared to manual decompression and an increased operating time. Single-arm meta-analysis found that overall mortality rates with IOCL was 4% (CI: 0.03-0.05). Rates of anastomotic leak and wound infection were 3% (CI: 0.02-0.04) and 12% (CI: 0.09-0.16) respectively.

CONCLUSION

IOCL leads to similar rates of post-operative complications compared to other procedures. More extensive studies are needed to assess the outcomes of IOCL for emergency left-sided colonic surgeries.

Different position from traditional left lateral for colonoscopy? A meta-analysis and systematic review of randomized control trials

BACKGROUND

Colonoscopy requires the intubation of the cecum for screening of colorectal diseases. The conventional position used for colonoscopy is the left lateral position (LLP). However, alternative positions have also been utilized to enhance the success of intubation. Thus, the aim of this study was to perform a meta-analysis of the different positions to determine the effectiveness of the individual positions for successful colonoscopy.

METHODS

Medline, Embase and Cochrane trials electronic databases were searched for studies on colonoscopy positions. The primary outcome was defined as the cecal intubation rate. Pooled risk ratios (RR) and 95% confidence intervals (CI) for the rates of cecal intubation were estimated. Secondary outcomes such as the cecal intubation time and adenoma detection rate were further analyzed qualitatively.

RESULTS

After reviewing 644 identified records, 7 randomized control trials (RCT) studies were included. No significant difference was observed in either comparisons, between the LLP vs. supine position (SP) (RR = 1.01, 95% CI, 0.98 to 1.04, P = 0.55) or the LLP vs. prone position (PP) (RR = 1.02, 95% CI, 0.98 to 1.06, P = 0.27).

CONCLUSIONS

Amidst available literature, the use of other positions can be considered when performing colonoscopy. These further highlights that the existential practice is based predominantly on familiarity instead of evidence-based-research.

Early surgery after bridge-to-surgery stenting for malignant bowel obstruction is associated with better oncological outcomes

BACKGROUND

Placement of self-expanding metal stents has been increasingly adopted as a bridge to surgery in patients presenting with obstructed left-sided colorectal cancers. The optimal bridging time has yet to be widely established, hence this retrospective study aims to determine the optimal bridging time to elective surgery post endoluminal stenting.

PATIENTS AND METHODS

All patients who underwent colorectal stenting for large bowel obstruction in a single, tertiary hospital in Singapore between January 2003 and December 2017 were retrospectively identified. Patients' baseline demographics, tumour characteristics, stent-related complications, intra-operative details, post-operative complications and oncological outcomes were analysed.

RESULTS

Of the 53 patients who successfully underwent colonic stenting for malignant left sided obstruction, 33.96% of patients underwent surgery within two weeks of stent placement while 66.04% of patients underwent surgery after 2 weeks of stent placement. Univariate analysis between both groups did not demonstrate significant differences in postoperative complications and stoma formation. Significant differences were observed between both groups for stent complications (38.89% vs 8.57%, p = 0.022), on-table decompression (38.89% vs 2.86%, p = 0.001) and systemic recurrence (11.11% vs 40.00%, p = 0.030). Increased bridging interval to surgery (OR 13.16, CI 1.37-126.96, p = 0.026) was a significant risk factor for systemic recurrence on multivariate analysis.

CONCLUSIONS

Patients undergoing definitive surgery within 2 weeks of colonic stenting may have better oncological outcomes without compromising on postoperative outcomes. Further prospective studies are required to compare outcomes between emergency surgery and different bridging intervals.

Metformin and colorectal cancer: a systematic review, meta-analysis and meta-regression

PURPOSE

Metformin may have a role in reducing the incidence of colorectal cancer (CRC) and improving survival outcome. This meta-analysis explored the effect of metformin use on colorectal adenoma and cancer incidence, and colorectal oncological outcomes.

METHODS

A database search was conducted on Medline, Embase and CNKI for studies comparing metformin vs. non-metformin users, metformin users vs. non-diabetics and metformin users vs. diabetics with diet-only treatment. Meta-analysis was done with DerSimonian and Laird with risk ratios (RR), and hazard ratios (HR) for survival outcomes.

RESULTS

We included 58 studies and summarized incidences of colorectal adenoma and cancer, as well as cancer survival outcomes. Metformin users had a significant lower incidence of colorectal adenoma (RR 0.77, CI 0.67-0.88, p < 0.001), advanced adenoma (0.61, CI 0.42-0.88, p = 0.008) and CRC (RR 0.76, CI 0.69-0.84, p < 0.001) respectively compared with non-metformin users. Overall survival (HR 0.6, CI 0.53-0.67, p < 0.001) and CRC-specific survival (HR 0.66, CI 0.59-0.74, p < 0.001) were higher among metformin users compared with non-metformin users. Further analysis on overall survival of metastatic CRC patients revealed significantly higher survival rates in metformin users (HR 0.77, CI 0.68-0.87, p < 0.001).

CONCLUSION

This meta-analysis showed that metformin use significantly reduces colorectal adenoma and cancer incidence and improves colorectal cancer outcomes.