Does the Choice of Extraction Site During Minimally Invasive Colorectal Surgery Change the Incidence of Incisional Hernia? Protocol for a Systematic Review and Network Meta-Analysis.

BACKGROUND: Various sites are used for specimen extraction in oncological minimally invasive colorectal surgery. The objective is to determine if the choice of extraction site modulates the incidence of incisional hernia (IH). METHODS/DESIGN: A systematic review will be performed in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. MEDLINE, Embase and CENTRAL will be searched to look for original studies reporting the incidence of IH after minimally invasive colorectal surgery. Studies will be excluded from the analysis if: 1) they do not report original data, 2) the outcome of interest (incidence of incisional hernia) is not clearly reported and does not allow to extrapolate and/or calculate the required data for network meta-analysis, 3) they include pediatric patients, 4) they include a patients' population with a conversion rate to laparotomy >10%, 5) they do not compare at least two different extraction sites for the operative specimen, 6) they report patients who underwent pure (and not hybrid) natural orifice transluminal endoscopic surgery (NOTES). Network meta-analysis will be performed to determine the incidence of IH per extraction site. DISCUSSION: By determining which specimen extraction site leads to reduced rate of IH, this systematic review and network meta-analysis will help colorectal surgeons to choose their extraction site and reduce the morbidity and costs associated with IH. REGISTRATION: The systematic review and meta-analysis protocol is registered in the International Prospective Register of Ongoing Systematic Reviews (PROSPERO) with number CRD42021272226. HIGHLIGHTS: Various sites are used for specimen extraction in oncological minimally invasive colorectal surgery, and the choice of the site may probably modulate the incidence of incisional hernia.The present protocol aims to design a systematic review which will identify original studies comparing two extraction sites during minimally invasive colorectal surgery in terms of incidence of incisional hernia.Network meta-analysis will be performed to determine the incidence of IH per extraction site

The aetiology and pathogenesis of rectal prolapse

It is still an enigma that some patients develop rectal prolapse whilst others with similar risk factors do not. Biomechanical assessment of the skin may provide further insight into the aetiology of this complex condition. Components of connective tissue other than collagen have been found to be involved in patients with rectal prolapse. Elastin fibres are an abundant and integral part of many extracellular matrices and are especially critical for providing the property of elastic recoil to tissues. The significance of elastin fibres is clearly reflected by the numerous human conditions in which a skin phenotype occurs as a result of elastin fibre abnormalities. The organization of elastic fibres differs between controls and subsets of patients with rectal prolapse, and their importance for maintaining the structural and functional integrity of the pelvic floor has been demonstrated in transgenic mice, with animals which have a null mutation in fibulin-5 (Fbln5&iexcl;/&iexcl;) developing prolapse. This study aimed to compare fibulin-5 expression in the skin of patients with and without rectal prolapse. Between January 2013 and February 2014, skin specimens were obtained during surgery from 20 patients with rectal prolapse and from 21 without prolapse undergoing surgery for other indications. Fibroblasts from the skin were cultured and the level of fibulin-5 expression was determined on cultured fibroblasts, isolated from these specimens by quantitative real-time polymerase chain reaction. Immunohistochemistry was performed on fixed tissue specimens to assess fibulin-5 expression. Orcein staining measured expression levels of elastin in the skin, and Image J. Tensile tests were performed using the Zwick Roell device, with custom ceramic clamps. For statistical analysis, Student's t test was used. Fibulin-5 mRNA expression and fibulin-5 staining intensity were significantly lower in young male patients with rectal prolapse compared with age matched controls [fibulin-5 mean _ SD mRNA relative units, 1.1 _ 0.41 vs 0.53 _ 0.22, P = 0.001; intensity score, median (range), 2 (0â3) vs 1 (0â3), P = 0.05]. There were no significant differences in the expression of fibulin-5 in women with rectal prolapse compared with controls. Histological analysis of prolapse vs control showed percentage dermal elastin fibres of 9 vs 5.8 &percnt; (p=0.001) in males and 6.5 vs 5.3 &percnt; (p=0.05) in females. Patients with more severe prolapse (external) had a significantly (p=0.05) higher percentage dermal elastin fibres 6.9 vs 6.1 &percnt; than internal prolapse. Young's modulus of patients with prolapse was lower in males (3.3 vs 2.8, p=0.05) and females (3.1 vs 2.7, p=0.05). Patients with prolapse have a higher concentration of elastin fibres in the skin, and these differences are quantitatively demonstrated through mechanical testing. This suggests that the aetiology may be a result of a dysfunction of elastin fibre assembly. Fibulin-5 may be implicated in the aetiology of rectal prolapse in a subgroup of young male patients.</p

The aetiology and pathogenesis of rectal prolapse

It is still an enigma that some patients develop rectal prolapse whilst others with similar risk factors do not. Biomechanical assessment of the skin may provide further insight into the aetiology of this complex condition. Components of connective tissue other than collagen have been found to be involved in patients with rectal prolapse. Elastin fibres are an abundant and integral part of many extracellular matrices and are especially critical for providing the property of elastic recoil to tissues. The significance of elastin fibres is clearly reflected by the numerous human conditions in which a skin phenotype occurs as a result of elastin fibre abnormalities. The organization of elastic fibres differs between controls and subsets of patients with rectal prolapse, and their importance for maintaining the structural and functional integrity of the pelvic floor has been demonstrated in transgenic mice, with animals which have a null mutation in fibulin-5 (Fbln5¡/¡) developing prolapse. This study aimed to compare fibulin-5 expression in the skin of patients with and without rectal prolapse. Between January 2013 and February 2014, skin specimens were obtained during surgery from 20 patients with rectal prolapse and from 21 without prolapse undergoing surgery for other indications. Fibroblasts from the skin were cultured and the level of fibulin-5 expression was determined on cultured fibroblasts, isolated from these specimens by quantitative real-time polymerase chain reaction. Immunohistochemistry was performed on fixed tissue specimens to assess fibulin-5 expression. Orcein staining measured expression levels of elastin in the skin, and Image J. Tensile tests were performed using the Zwick Roell device, with custom ceramic clamps. For statistical analysis, Student's t test was used. Fibulin-5 mRNA expression and fibulin-5 staining intensity were significantly lower in young male patients with rectal prolapse compared with age matched controls [fibulin-5 mean _ SD mRNA relative units, 1.1 _ 0.41 vs 0.53 _ 0.22, P = 0.001; intensity score, median (range), 2 (0–3) vs 1 (0–3), P = 0.05]. There were no significant differences in the expression of fibulin-5 in women with rectal prolapse compared with controls. Histological analysis of prolapse vs control showed percentage dermal elastin fibres of 9 vs 5.8 &amp;percnt; (p=0.001) in males and 6.5 vs 5.3 &amp;percnt; (p=0.05) in females. Patients with more severe prolapse (external) had a significantly (p=0.05) higher percentage dermal elastin fibres 6.9 vs 6.1 &amp;percnt; than internal prolapse. Young's modulus of patients with prolapse was lower in males (3.3 vs 2.8, p=0.05) and females (3.1 vs 2.7, p=0.05). Patients with prolapse have a higher concentration of elastin fibres in the skin, and these differences are quantitatively demonstrated through mechanical testing. This suggests that the aetiology may be a result of a dysfunction of elastin fibre assembly. Fibulin-5 may be implicated in the aetiology of rectal prolapse in a subgroup of young male patients.</p

Should prophylactic transanal tube drainage be continued in colorectal surgery?

In the first randomized clinical trial in the field to our knowledge, Zhao et al1 report that the insertion of a transanal tube (TT) does not reduce the 30-day incidence of anastomotic leakage (AL) in patients who underwent low anterior resection. We would like to point out a few design issues that we think limit the interpretation and external validity of the trial

A unique case of appendiceal diverticulum presenting with positive faecal immunochemical test

Appendiceal diverticulum is a rare condition that usually presents with symptoms similar to acute appendicitis. Although imaging can be used to aid the diagnosis of this condition, it is usually confirmed postoperatively on the basis of histology. Because of an increased risk of appendiceal neoplasms, the usual management is prophylactic appendicectomy. We report the case of a 70-year-old lady with no symptoms referred from her GP surgery for a positive faecal immunochemical test as part of the bowel screening programme. Colonoscopy showed a mass at the appendiceal orifice with normal histology. She underwent an appendicectomy with a small cuff of caecal resection. The lesion was ~8 cm at its maximum dimension and showed appendiceal diverticulum. Appendiceal diverticulum is an important differential diagnosis to consider in patients with atypical history of acute appendicitis or positive faecal immunochemical test with no other symptoms

Fluorescence angiography likely protects against anastomotic leak in colorectal surgery: a systematic review and meta-analysis of randomised controlled trials.

Funder: University of GenevaOBJECTIVE: Observational studies have shown that fluorescence angiography (FA) decreases the incidence of anastomotic leak (AL) in colorectal surgery, but high-quality pooled evidence was lacking. Therefore, we aimed at confirming this preliminary finding using a systematic review and meta-analysis of randomised controlled trials (RCTs) in the field. METHODS: MEDLINE, Embase and CENTRAL were searched for RCTs assessing the effect of intra-operative FA versus standard assessment of bowel perfusion on the incidence of AL of colorectal anastomosis. The systematic review complied with the PRISMA 2020 and AMSTAR2 recommendations and was registered in PROSPERO. Pooled relative risk (RR) and pooled risk difference (RD) were obtained using models with random effects. Heterogeneity was assessed using the Q-test and quantified using the I2 value. Certainty of evidence was assessed using the GRADE Pro tool. RESULTS: One hundred and eleven articles were screened, 108 were excluded and three were kept for inclusion. The three included RCTs compared assessment of the perfusion of the bowel during creation of a colorectal anastomosis using FA versus standard practice. In meta-analysis, FA was significantly protective against AL (3 RCTs, 964 patients, RR: 0.67, 95% CI: 0.46 to 0.99, I2: 0%, p = 0.04). The RD of AL was non-significantly decreased by 4 percentage points (95%CI: - 0.08 to 0, I2: 8%, p = 0.06) when using FA. Certainty of evidence was considered as moderate. CONCLUSION: The effect of FA on prevention of AL in colorectal surgery exists but is potentially of small magnitude. Considering the potential magnitude of effect of FA, we advise that future RCTs have an adequate sample size, include a cost-benefit analysis of the technique and better define the subpopulation who could benefit from FA

The Role of Preoperative Imaging in the Detection of Lateral Lymph Node Metastases in Rectal Cancer : A Systematic Review and Diagnostic Test Meta-analysis

Background: Different techniques exist for the imaging of lateral lymph nodes in rectal cancer. Objective: This study aimed to compare the diagnostic accuracy of pelvic MRI, 18 F-FDG-PET/CT, and 18 F-FDG-PET/MRI for the identification of lateral lymph node metastases in rectal cancer. Data sources: Data sources include PubMed, Embase, Cochrane Library, and Google Scholar. Study selection: All studies evaluating the diagnostic accuracy of pelvic MRI, 18 F-FDG-PET/CT, and 18 F-FDG-PET/MRI for the preoperative detection of lateral lymph node metastasis in patients with rectal cancer were selected. Interventions: The interventions were pelvic MRI, 18 F-FDG-PET/CT, and/or 18 F-FDG-PET/MRI. Main outcome measures: Definitive histopathology was used as a criterion standard. Results: A total of 20 studies (1,827 patients) were included out of an initial search yielding 7,360 studies. The pooled sensitivity of pelvic MRI was 0.88 (95% CI, 0.85-0.91), of 18 F-FDG-PET/CT was 0.83 (95% CI, 0.80-0.86), and of 18 F-FDG-PET/MRI was 0.72 (95% CI, 0.51-0.87) for the detection of lateral lymph node metastasis. The pooled specificity of pelvic MRI was 0.85 (95% CI, 0.78-0.90), of 18 F-FDG-PET/CT was 0.95 (95% CI, 0.86-0.98), and of 18 F-FDG-PET/MRI was 0.90 (95% CI, 0.78-0.96). The area under the curve was 0.88 (95% CI, 0.85-0.91) for pelvic MRI and was 0.83 (95% CI, 0.80-0.86) for 18 F-FDG-PET/CT. Limitations: Heterogeneity in terms of patients' populations, definitions of suspect lateral lymph nodes, and administration of neoadjuvant treatment. Conclusions: For the preoperative identification of lateral lymph node metastasis in rectal cancer, this review found compelling evidence that pelvic MRI should constitute the imaging modality of choice. In contrast, to confirm the presence of lateral lymph node metastasis, 18 F-FDG-PET/MRI modalities allow discarding false positive cases because of increased specificity. Prospero registration number: CRD42020200319.</p