Evaluation status of current and emerging minimally invasive robotic surgical platforms.

BACKGROUND: The rapid adoption of robotics within minimally invasive surgical specialties has also seen an explosion of new technology including multi- and single port, natural orifice transluminal endoscopic surgery (NOTES), endoluminal and "on-demand" platforms. This review aims to evaluate the validation status of current and emerging MIS robotic platforms, using the IDEAL Framework. METHODS: A scoping review exploring robotic minimally invasive surgical devices, technology and systems in use or being developed was performed, including general surgery, gynaecology, urology and cardiothoracics. Systems operating purely outside the abdomen or thorax and endoluminal or natural orifice platforms were excluded. PubMed, Google Scholar, journal reports and information from the public domain were collected. Each company was approached via email for a virtual interview to discover more about the systems and to quality check data. The IDEAL Framework is an internationally accepted tool to evaluate novel surgical technology, consisting of four stages: idea, development/exploration, assessment, and surveillance. An IDEAL stage, synonymous with validation status in this review, was assigned by reviewing the published literature. RESULTS: 21 companies with 23 different robotic platforms were identified for data collection, 13 with national and/or international regulatory approval. Of the 17 multiport systems, 1 is fully evaluated at stage 4, 2 are stage 3, 6 stage 2b, 2 at stage 2a, 2 stage 1, and 4 at the pre-IDEAL stage 0. Of the 6 single-port systems none have been fully evaluated with 1 at stage 3, 3 at stage 1 and 2 at stage 0. CONCLUSIONS: The majority of existing robotic platforms are currently at the preclinical to developmental and exploratory stage of evaluation. Using the IDEAL framework will ensure that emerging robotic platforms are fully evaluated with long-term data, to inform the surgical workforce and ensure patient safety.

CLASSICA: Validating artificial intelligence in classifying cancer in real time during surgery.

AIM: Treatment pathways for significant rectal polyps differ depending on the underlying pathology, but pre-excision profiling is imperfect. It has been demonstrated that differences in fluorescence perfusion signals following injection of indocyanine green (ICG) can be analysed mathematically and, with the assistance of artificial intelligence (AI), used to classify tumours endoscopically as benign or malignant. This study aims to validate this method of characterization across multiple clinical sites regarding its generalizability, usability and accuracy while developing clinical-grade software to enable it to become a useful method. METHODS: The CLASSICA study is a prospective, unblinded multicentre European observational study aimed to validate the use of AI analysis of ICG fluorescence for intra-operative tissue characterization. Six hundred patients undergoing transanal endoscopic evaluation of significant rectal polyps and tumours will be enrolled in at least five clinical sites across the European Union over a 4-year period. Video recordings will be analysed regarding dynamic fluorescence patterns centrally as software is developed to enable analysis with automatic classification to happen locally. AI-based classification and subsequently guided intervention will be compared with the current standard of care including biopsies, final specimen pathology and patient outcomes. DISCUSSION: CLASSICA will validate the use of AI in the analysis of ICG fluorescence for the purposes of classifying significant rectal polyps and tumours endoscopically. Follow-on studies will compare AI-guided targeted biopsy or, indeed, AI characterization alone with traditional biopsy and AI-guided local excision versus traditional excision with regard to marginal clearance and recurrence.

European Association for Endoscopic Surgery (EAES) consensus on Indocyanine Green (ICG) fluorescence-guided surgery.

BACKGROUND: In recent years, the use of Indocyanine Green (ICG) fluorescence-guided surgery during open and laparoscopic procedures has exponentially expanded across various clinical settings. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on this topic with the aim of creating evidence-based statements and recommendations for the surgical community. METHODS: An expert panel of surgeons has been selected and invited to participate to this project. Systematic reviews of the PubMed, Embase and Cochrane libraries were performed to identify evidence on potential benefits of ICG fluorescence-guided surgery on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by the panel; they were then submitted to all EAES members through a two-rounds online survey and results presented at the EAES annual congress, Barcelona, November 2021. RESULTS: A total of 18,273 abstracts were screened with 117 articles included. 22 statements and 16 recommendations were generated and approved. In some areas, such as the use of ICG fluorescence-guided surgery during laparoscopic cholecystectomy, the perfusion assessment in colorectal surgery and the search for the sentinel lymph nodes in gynaecological malignancies, the large number of evidences in literature has allowed us to strongly recommend the use of ICG for a better anatomical definition and a reduction in post-operative complications. CONCLUSIONS: Overall, from the systematic literature review performed by the experts panel and the survey extended to all EAES members, ICG fluorescence-guided surgery could be considered a safe and effective technology. Future robust clinical research is required to specifically validate multiple organ-specific applications and the potential benefits of this technique on clinical outcomes.

Initial clinical experience with a novel flexible endoscopic robot for transanal surgery.

BACKGROUND: The Flex® Robotic System (Medrobotics, Raynham, MA, USA) is the first miniaturised flexible endoscopic robot that aims to allow surgical manoeuvres beyond the area currently reached by transanal endoscopic microsurgery. The aim of this study is to evaluate our initial clinical experience with this novel tool. METHODS: We prospectively collected all consecutive cases of local excisions of rectal lesions performed with the Flex® Robotic System performed at the Department of Surgical Sciences of the University of Turin between October 2018 and December 2019. Indications were benign, or early rectal lesions judged unsuitable for endoscopic removal, within 20 cm of the anal verge. Debriefing meetings after each procedure allowed technology assessment leading to the modification, development, and implementation of tools according to the clinical experience. We analysed the data in terms of the safety and efficacy of treatment. RESULTS: Between October 2018 and February 2020, 26 patients were treated. We performed a full-thickness excision in 14 patients and a submucosal dissection in 12. The median operating time was 115 min (range 45-360 min). In six patients (23.1%), we converted to standard transanal endoscopic operation (TEO®) (Karl Storz, Tuttlingen, Germany) to complete the procedure. The 30-day morbidity rate was 11.5% (3/26). Positive resection margins were detected in 4 (15.4%) patients. At a minimum follow-up of 12 months, 2 (7.7%) local recurrences were observed. CONCLUSIONS: This first clinical series demonstrates that the Flex® Robotic System is a fascinating technology that deserves further development to increase surgical dexterity, thereby overcoming current technical limitations and improving clinical outcomes.

Could fluorescence-guided surgery be an efficient and sustainable option? A SICE (Italian Society of Endoscopic Surgery) health technology assessment summary.

BACKGROUND: Indocyanine green fluorescence vision is an upcoming technology in surgery. It can be used in three ways: angiographic and biliary tree visualization and lymphatic spreading studies. The present paper shows the most outstanding results from an health technology assessment study design, conducted on fluorescence-guided compared with standard vision surgery. METHODS: A health technology assessment approach was implemented to investigate the economic, social, ethical, and organizational implications related to the adoption of the innovative fluorescence-guided view, with a focus on minimally invasive approach. With the support of a multidisciplinary team, qualitative and quantitative data were collected, by means of literature evidence, validated questionnaires and self-reported interviews, considering the dimensions resulting from the EUnetHTA Core Model. RESULTS: From a systematic search of literature, we retrieved the following studies: 6 on hepatic, 1 on pancreatic, 4 on biliary, 2 on bariatric, 4 on endocrine, 2 on thoracic, 11 on colorectal, 7 on urology, 11 on gynecology, 2 on gastric surgery. Fluorescence guide has shown advantages on the length of hospitalization particularly in colorectal surgery, with a reduction of the rate of leakages and re-do anastomoses, in spite of a slight increase in operating time, and is confirmed to be a safe, efficacious, and sustainable vision technology. Clinical applications are still presenting a low evidence in the literature. CONCLUSION: The present paper, under the patronage of Italian Society of Endoscopic Surgery, based on an HTA approach, sustains the use of fluorescence-guided vision in minimally invasive surgery, in the fields of general, gynecologic, urologic, and thoracic surgery, as an efficient and economically sustainable technology.

The REAL (REctal Anastomotic Leak) score for prediction of anastomotic leak after rectal cancer surgery.

BACKGROUND: Anastomotic leak after rectal cancer surgery is a severe complication associated with poorer oncologic outcome and quality of life. Preoperative assessment of the risk for anastomotic leak is a key component of surgical planning, including the opportunity to create a defunctioning stoma. OBJECTIVE: The purpose of this study was to identify and quantify the risk factors for anastomotic leak to minimize risk by either not restoring bowel continuity or protecting the anastomosis with a temporary diverting stoma. METHODS: Potentially relevant studies were identified from the following databases: PubMed, Embase and Cochrane Library. This meta-analysis included studies on transabdominal resection for rectal cancer that reported data about anastomotic leak. The risk for anastomotic leak after rectal cancer surgery was investigated. Preoperative, intraoperative, and postoperative factors were extracted and used to compare anastomotic leak rates. All variables demonstrating a p value < 0.1 in the univariate analysis were entered into a multivariate logistic regression model to determine the risk factors for anastomotic leak. RESULTS: Twenty-six centers provided individual data on 9735 patients. Selected preoperative covariates (time before surgery, age, gender, smoking, previous abdominal surgery, BMI, diabetes, ASA, hemoglobin level, TNM classification stage, anastomotic distance) were used as independent factors in a logistic regression model with anastomotic leak as dependent variable. With a threshold value of the receiver operating characteristics (ROC) curve corresponding to 0.0791 in the training set, the area under the ROC curve (AUC) was 0.585 (p < 0.0001). Sensitivity and specificity of the model's probability > 0.0791 to identify anastomotic leak were 79.1% and 32.9%, respectively. Accuracy of the threshold value was confirmed in the validation set with 77.8% sensitivity and 35.2% specificity. CONCLUSIONS: We trust that, with further refinement using prospective data, this nomogram based on preoperative risk factors may assist surgeons in decision making. The score is now available online ( http://www.real-score.org ).

Is the outpatient management of acute diverticulitis safe and effective? A systematic review and meta-analysis.

BACKGROUND: In Western countries, the incidence of acute diverticulitis (AD) is increasing. Patients with uncomplicated diverticulitis can undergo a standard antibiotic treatment in an outpatient setting. The aim of this systematic review was to assess the safety and efficacy of the management of acute diverticulitis in an outpatient setting. METHODS: A literature search was performed on PubMed, Scopus, Embase, Central and Web of Science up to September 2018. Studies including patients who had outpatient management of uncomplicated acute diverticulitis were considered. We manually checked the reference lists of all included studies to identify any additional studies. Primary outcome was the overall failure rates in the outpatient setting. The failure of outpatient setting was defined as any emergency hospital admission in patients who had outpatient treatment for AD in the previous 60 days. A subgroup analysis of failure was performed in patients with AD of the left colon, with or without comorbidities, with previous episodes of AD, in patients with diabetes, with different severity of AD (pericolic air and abdominal abscess), with or without antibiotic treatment, with ambulatory versus home care unit follow-up, with or without protocol and where outpatient management is a common practice. The secondary outcome was the rate of emergency surgical treatment or percutaneous drainage in patients who failed outpatient treatment. RESULTS: This systematic review included 21 studies including 1781 patients who had outpatient management of AD  including 11 prospective, 9 retrospective and only 1 randomized trial. The meta-analysis showed that outpatient management is safe, and the overall failure rate in an outpatient setting was 4.3% (95% CI 2.6%-6.3%). Localization of diverticulitis is not a selection criterion for an outpatient strategy (p 0.512). The other subgroup analyses did not report any factors that influence the rate of failure: previous episodes of acute diverticulitis (p = 0.163), comorbidities (p = 0.187), pericolic air (p = 0.653), intra-abdominal abscess (p = 0.326), treatment according to a registered protocol (p = 0.078), type of follow-up (p = 0.700), type of antibiotic treatment (p = 0.647) or diabetes (p = 0.610). In patients who failed outpatient treatment, the majority had prolonged antibiotic therapy and only few had percutaneous drainage for an abscess (0.13%) or surgical intervention for perforation (0.06%). These results should be interpreted with some caution because of the low quality of available data. CONCLUSIONS: The outpatient management of AD can reduce the rate of emergency hospitalizations. This setting is already part of the common clinical practice of many emergency departments, in which a standardized protocol is followed. The data reported suggest that this management is safe if associated with an accurate selection of patients (40%); but no subgroup analysis demonstrated significant differences between groups (such as comorbidities, previous episode, diabetes). The main limitations of the findings of the present review concern their applicability in common clinical practice as it was impossible to identify strict criteria of failure.

Individual participant data pooled-analysis of risk factors for recurrence after neoadjuvant radiotherapy and transanal local excision of rectal cancer: the PARTTLE study.

BACKGROUND: An organ-preserving strategy may be a valid alternative in the treatment of selected patients with rectal cancer after neoadjuvant radiotherapy. Preoperative assessment of the risk for tumor recurrence is a key component of surgical planning. The aim of the present study was to increase the current knowledge on the risk factors for tumor recurrence. METHODS: The present study included individual participant data of published studies on rectal cancer surgery. The literature was reviewed according to according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Individual Participant Data checklist (PRISMA-IPD) guidelines. Series of patients, whose data were collected prospectively, having neoadjuvant radiotherapy followed by transanal local excision for rectal cancer were reviewed. Three independent series of univariate/multivariate binary logistic regression models were estimated for the risk of local, systemic and overall recurrence, respectively. RESULTS: We identified 15 studies, and 7 centers provided individual data on 517 patients. The multivariate analysis showed higher local and overall recurrences for ypT3 stage (OR 4.79; 95% CI 2.25-10.16 and OR 6.43 95% CI 3.33-12.42), tumor size after radiotherapy > 10 mm (OR 5.86 95% CI 2.33-14.74 and OR 3.14 95% CI 1.68-5.87), and lack of combined chemotherapy (OR 3.68 95% CI 1.78-7.62 and OR 2.09 95% CI 1.10-3.97), while ypT3 was the only factor correlated with systemic recurrence (OR 5.93). The analysis of survival curves shows that the overall survival is associated with ypT and not with cT. CONCLUSIONS: Local excision should be offered with caution after neoadjuvant chemoradiotherapy to selected patients with rectal cancers, who achieved a good response to neoadjuvant chemoradiotherapy.

Multicentre international trial of laparoscopic lavage for Hinchey III acute diverticulitis (LLO Study).

BACKGROUND: Laparoscopic lavage was proposed in the 1990s to treat purulent peritonitis in patients with perforated acute diverticulitis. Prospective randomized trials had mixed results. The aim of this study was to determine the success rate of laparoscopic lavage in sepsis control and to identify a group of patients that could potentially benefit from this treatment. METHODS: This retrospective multicentre international study included consecutive patients from 24 centres who underwent laparoscopic lavage from 2005 to 2015. RESULTS: A total of 404 patients were included, 231 of whom had Hinchey III acute diverticulitis. Sepsis control was achieved in 172 patients (74·5 per cent), and was associated with lower Mannheim Peritonitis Index score and ASA grade, no evidence of free perforation, absence of extensive adhesiolysis and previous episodes of diverticulitis. The operation was immediately converted to open surgery in 19 patients. Among 212 patients who underwent laparoscopic lavage, the morbidity rate was 33·0 per cent; the reoperation rate was 13·7 per cent and the 30-day mortality rate 1·9 per cent. Twenty-one patients required readmission for early complications, of whom 11 underwent further surgery and one died. Of the 172 patients discharged uneventfully after laparoscopic lavage, a recurrent episode of acute diverticulitis was registered in 46 (26·7 per cent), at a mean of 11 (range 2-108) months. Relapse was associated with younger age, female sex and previous episodes of acute diverticulitis. CONCLUSION: Laparoscopic lavage showed a high rate of successful sepsis control in selected patients with perforated Hinchey III acute diverticulitis affected by peritonitis, with low rates of operative mortality, reoperation and stoma formation.

Single-incision laparoscopic cholecystectomy is responsible for increased adverse events: results of a meta-analysis of randomized controlled trials.

BACKGROUND: Over the last decade, single-incision laparoscopic cholecystectomy (SLC) has gained popularity, although it is not evident if benefits of this procedure overcome the potential increased risk. Aim of the study is to compare the outcome of SLC with conventional multi-incision laparoscopic cholecystectomy (MLC) in a meta-analysis of randomized controlled trials only. METHODS: A systematic Medline, Embase, and Cochrane Central Register of Controlled Trials literature search of articles on SLC and MLC for any indication was performed in June 2017. The main outcomes measured were overall adverse events, pain score (VAS), cosmetic results, quality of life, and incisional hernias. Linear regression was used to model the effect of each procedure on the different outcomes. RESULTS: Forty-six trials were included and data from 5141 participants were analysed; 2444 underwent SLC and 2697 MLC, respectively. Mortality reported was nil in both treatment groups. Overall adverse events were higher in the SLC group (RR 1.41; p < 0.001) compared to MLC group, as well severe adverse events (RR 2.06; p < 0.001) and even mild adverse events (RR 1.23; p = 0.041). This was confirmed also when only trials including 4-port techniques (RR 1.37, p = 0.004) or 3-port techniques were considered (RR 1.89, p = 0.020). The pain score showed a standardized mean difference (SMD) of - 0.36 (p < 0.001) in favour of SLC. Cosmetic outcome by time point scored a SMD of 1.49 (p < 0.001) in favour of SLC. Incisional hernias occurred more frequently (RR 2.97, p = 0.005) in the SLC group. CONCLUSIONS: Despite SLC offers a better cosmetic outcome and reduction of pain, the consistent higher rate of adverse events, both severe and mild, together with the higher rate of incisional hernias, should suggest to reconsider the application of single incision techniques when performing cholecystectomy with the existing technology.

Comparison of outcomes following intersphincteric resection vs low anterior resection for low rectal cancer: a systematic review.

BACKGROUND: Low Rectal Anterior Resection (LAR) is challenging when anal canal mucosa and/or internal sphincter are involved by very low tumors. In these cases, Intersphincteric resection (ISR) with the removal of the internal sphincter is designed to increase the distal margin of resection, thus preserving the external sphincter and pubo-rectalis muscle complex. Aim is to compare results after ISR with those of LAR, including subgroup analysis of open, laparoscopic and robotic ISR. METHODS: Studies published from January 1991 to January 2017 describing ISR and comparing results with LAR in adults were included irrespective of the technique. Tumor and surgical characteristics, clinical, functional and oncological results were collected. RESULTS: 25 non-randomized studies were included. Postoperative mortality ranged between 0% and 2.3%. The hospital stay ranged from 5 days to 40 days, lower in robotic ISR group if compared with laparoscopic ISR. Patients avoiding permanent stoma with ISR accept a lower continence level as satisfactory. Furthermore, anorectal function after ISR often tends to improve. ISR and LAR presented not statistically significant differences. Oncological outcomes were not statistically different Morbidity, blood loss and need for blood transfusions were lower in the laparoscopic ISR if compared with open approach. CONCLUSIONS: Morbidity could more frequently affect open ISR if compared with laparoscopic ISR. Functional outcomes were influenced by neoadjuvant CRT, but not by the surgical approach of reconstruction, while were positively influenced by partial ISR with respect to total ISR.

Laparoscopic lavage versus surgical resection for acute diverticulitis with generalised peritonitis: a systematic review and meta-analysis.

This systematic review and meta-analysis investigates current evidence on the therapeutic role of laparoscopic lavage in the management of diverticular peritonitis. A systematic review of the literature was performed on PubMed until June 2016, according to preferred reporting items for systematic reviews and meta-analyses guidelines. All randomised controlled trials comparing laparoscopic lavage with surgical resection, irrespective of anastomosis or stoma formation, were analysed. After assessment of titles and full text, 3 randomised trials fulfilled the inclusion criteria. Overall the quality of evidence was low because of serious concerns regarding the risk of bias and imprecision. In the laparoscopic lavage group, there was a statistically significant higher rate of postoperative intra-abdominal abscess (RR 2.54, 95% CI 1.34-4.83), a lower rate of postoperative wound infection (RR 0.10, 95% CI 0.02-0.51), and a shorter length of postoperative hospital stay during index admission (WMD = -2.03, 95% CI -2.59 to -1.47). There were no statistically significant differences in terms of postoperative mortality at index admission or within 30 days from intervention in all Hinchey stages and in Hinchey stage III, postoperative mortality at 12 months, surgical reintervention at index admission or within 30-90 days from index intervention, stoma rate at 12 months, or adverse events within 90 days of any Clavien-Dindo grade. The surgical reintervention rate at 12 months from index intervention was significantly lower in the laparoscopic lavage group (RR 0.57, 95% CI 0.38-0.86), but these data included emergency reintervention and planned intervention (stoma reversal). This systematic review and meta-analysis did not demonstrate any significant difference between laparoscopic peritoneal lavage and traditional surgical resection in patients with peritonitis from perforated diverticular disease, in terms of postoperative mortality and early reoperation rate. Laparoscopic lavage was associated with a lower rate of stoma formation. However, the finding of a significantly higher rate of postoperative intra-abdominal abscess in patients who underwent laparoscopic lavage compared to those who underwent surgical resection is of concern. Since the aim of surgery in patients with peritonitis is to treat the sepsis, if one technique is associated with more postoperative abscesses, then the technique is ineffective. Even so, laparoscopic lavage does not appear fundamentally inferior to traditional surgical resection and this technique may achieve reasonable outcomes with minimal invasiveness.

A systematic analysis of controlled clinical trials using the NiTi CAR™ compression ring in colorectal anastomoses.

Anastomotic leak following colorectal surgery can be a devastating adverse event. The ideal stapling device should be capable of rapid creation of an anastomosis with serosal apposition without the persistence of a foreign body or a foreign body reaction which potentially contribute to early anastomotic dehiscence or late anastomotic stricture. A systematic review was performed examining available data on controlled randomized and non-randomized trials assessing the NiTi compression anastomosis ring-(NiTi CAR™) (NiTi Solutions, Netanyah Israel) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards. A protocol for this meta-analysis has been registered on PROSPERO (CRD42016050934). The initial search yielded 45 potentially relevant articles. After screening titles and abstracts for relevance and assessment for eligibility, 39 of these articles were eventually excluded leaving 6 studies for analysis in the review. Regarding the primary outcome measure, the overall anastomotic leak rate was 2.2% (5/230) in the compression anastomosis group compared with 3% (10/335) in the conventional anastomosis group; this difference was not statistically significant (RR 0.75, 95% CI 0.25-2.24; participants = 565; studies = 6; I 2 = 0%). There were no statistically significant differences between compression and conventional anastomoses in any of the secondary outcomes. This review was unable to demonstrate any statistically significant differences in favor of the compression anastomosis technique over conventional manual or stapled mechanical anastomoses.

Transanal Endoscopic Operation under spinal anaesthesia.

BACKGROUND: Transanal Endoscopic Operation (TEO(®) ) for rectal benign lesions and early rectal cancer may provide better oncological outcomes than flexible endoscopy. The major advantage of flexible endoscopy is that it does not require general anaesthesia. This prospective observational study assessed the feasibility and safety of TEO(®) performed under spinal anaesthesia. METHODS: The study population comprised eligible consecutive patients who underwent TEO(®) under spinal anaesthesia with curative or palliative intent for rectal neoplasms larger than 20 mm in diameter or for recurrent lesions of any size. The primary endpoints were feasibility and safety; secondary endpoints were postoperative pain, as measured on a visual analogue scale, heart rate, systolic and diastolic BP, opioid requested, postoperative nausea or vomiting, and urinary retention. RESULTS: The study included 50 patients (median age 70 years; 29 men and 21 women). No intraoperative complications occurred. The median duration of operation was 60 (range 20-165) min. No opioids were requested during the perioperative or postoperative period. The median postoperative pain score was 0 at 4, 8, 24 and 48 h after surgery. There were no significant fluctuations in heart rate, systolic and diastolic BP up to 48 h after the procedure (P = 0·379, P = 0·386 and P = 0·617 respectively). Postoperative nausea and vomiting occurred in one patient, and urinary retention in four. CONCLUSION: TEO(®) under spinal anaesthesia was safe and feasible with no conversions to general anaesthesia.

Transanal endoscopic microsurgery for giant circumferential rectal adenomas.

AIM: Transanal endoscopic microsurgery (TEM) was originally invented by Buess et al. (Chirurg, 1984, 55, 677-80) for the treatment of infraperitoneal rectal adenomas. Its indications have progressively expanded to include larger and more advanced lesions. The aim of the study was to report the results of TEM used for the treatment of circumferential rectal lesions. METHOD: We retrospectively reviewed the medical records of 17 consecutive patients [median age 69 (32-89) years; nine men] who underwent TEM for a circumferential rectal lesion in our department between September 2010 and January 2015. RESULTS: The median distance from the anal verge was 4 (3-11) cm, the median longitudinal extent was 7 (3-10) cm and the median surface area was 75 (40-255) cm(2) . An end-to-end anastomosis without proximal bowel mobilization was completed endoscopically in all cases. The median operating time was 120 (40-240) min. Persistent, endoscopically uncontrollable endoluminal bleeding in one patient was successfully treated with a second TEM procedure. One patient underwent preoperative radiotherapy for adenocarcinoma detected at the preoperative assessment. Surgical histology showed a pT3 cancer in one patient who refused further surgery, a pT2 cancer in two who subsequently underwent abdominoperineal resection, a pT1 cancer in four and a ypT0 in one patient. All are at present free of disease. No patients developed faecal incontinence or urinary or sexual dysfunction. Four patients required endoscopic balloon dilatation for stenosis. CONCLUSION: Transanal endoscopic microsurgery is a feasible and safe technique for large circumferential lesions with a satisfactory outcome. Preoperative staging may be inaccurate.

Complications during colonoscopy: prevention, diagnosis, and management.

Colonoscopy is largely performed in daily clinical practice for both diagnostic and therapeutic purposes. Although infrequent, different complications may occur during the examination, mostly related to the operative procedures. These complications range from asymptomatic and self-limiting to serious, requiring a prompt medical, endoscopic or surgical intervention. In this review, the complications that may occur during colonoscopy are discussed, with a particular focus on prevention, diagnosis, and therapeutic approaches.