ctDNA as a predictor of outcome after curative resection for locally advanced rectal cancer: systematic review and meta-analysis.

AIM: To assess the efficacy of ctDNA measurement at different time intervals in predicting response and prognosis in patients diagnosed with locally advanced rectal cancer (LARC) who underwent neoadjuvant treatment prior to curative resection. METHOD: English language randomized controlled trials and observational studies, published from 1946 to January 2024, comparing outcomes between ctDNA-positive and ctDNA-negative patients with LARC undergoing neoadjuvant treatment prior to curative surgical resection were included in the search. The search included Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and the Cochrane Database of Systematic Reviews (CDSR). RESULTS: Data for 1022 patients were analysed. Patients with positive ctDNA in the preoperative period had more than five times the risk of developing distant metastasis (RR [95% CI] 5.03 [3.31-7.65], p < 0.001), while those with positive ctDNA in the postoperative period had more than six times the risk (RR [95% CI] 6.17 [2.38-15.95], p < 0.001). There was no significant relationship between ctDNA status at baseline, pre-, or postoperative periods and achievement of pCR (RR [95% CI] 1.21 [0.86-1.7], 1.82 [0.94-3.55], 1.48 [0.78-2.82], p = 0.27, 0.08, and 0.23, respectively). However, patients with positive ctDNA in the pre- and postoperative periods had more than 13 and 12 times the risk of overall disease relapse after curative-intent treatment (RR [95% CI] 13.55 [7.12-25.81], 12.14 [3.19-46.14], p < 0.001), respectively. CONCLUSION: ctDNA could potentially guide treatment and follow-up in LARC, predicting high-risk patients for disease relapse, allowing individualized surveillance and treatment strategies. Prospective studies are needed for standardization.

Postoperative Ileus after Minimally Invasive Colorectal Surgery: A Summary of Current Strategies for Prevention and Management.

BACKGROUND: Postoperative ileus (POI) is one of the most common postoperative complications after colorectal surgery and prolongs hospital stays. Minimally invasive surgery (MIS) has reduced POI, but it remains common. This review explores the current methods for preventing and managing POI after MIS. SUMMARY: Preoperative interventions, including optimising nutrition, preoperative medicationn, and mechanical bowel preparation with oral antibiotics, may have a role in preventing POI. Transversus abdominis plane blocks and lidocaine could replace epidural analgesia in MIS. Fluid overload should be avoided; in some cases, goal-directed fluid therapy may aid in achieving this. Pharmacological agents, such as prucalopride and dexmedetomidine, could target mechanisms underlying POI. New strategies to stimulate vagal nerve activity may promote postoperative gastrointestinal motility. Preoperative bowel stimulation could potentially reduce POI following loop ileostomy closure. However, the evidence base for several interventions remains weak and requires further corroboration with robust studies. KEY MESSAGES: Despite the increasing use of MIS, POI remains a major issue following colorectal surgery. Further strategies to prevent POI are rapidly emerging. Studies using standardised definitions and perioperative care will help validate these interventions and remove barriers to accurate meta-analysis. Future studies should focus on establishing the impact of these interventions on POI after MIS specifically.

Does adding lateral pelvic lymph node dissection to neoadjuvant chemotherapy improve outcomes in low rectal cancer?

PURPOSE: Lateral pelvic lymph node metastasis occurs in 15 to 20% of patients with locally advanced low rectal cancer which increases risk of local recurrence and reduced survival following neoadjuvant chemoradiotherapy (nCRT) and total mesorectal excision (TME). Adding lateral pelvic lymph node dissection (LPLND) could improve outcomes in those patients. This review aims to determine if the addition of LPLND to the conventional management of advanced rectal cancer would yield improved outcomes. METHODS: OVID Medline, Cochrane, Clinicaltrials.gov , EMBASE, Clinicaltrialsregister.eu, Web of Knowledge and CABAbstracts were searched using the following keywords: 'lateral pelvic lymph node dissection', 'pelvis lymphadenectomy', 'chemoradi*', 'rectal cancer', 'rectal neoplasm', 'rectal carcinoma' and 'rectal tumour'. Studies were included if they were in English and included rectal cancer patients that had nCRT, rectal resection ± LPLND. Primary outcome was 3-year and 5-year local recurrence. Secondary outcome was 3-year and 5-year overall survival. RESULTS: Six studies were identified with 1210 patients who had nCRT and TME, and 268 patients who had nCRT and rectal resection plus LPLND. Patients who had LPLND had non-significant lower 3-year and 5-year local recurrence rate compared with those who did not (p = 0.10 and p = 0.12, respectively). They demonstrated a lower 3-year overall survival but higher 5-year overall survival and both were not significant (p = 0.81 and p = 0.57, respectively). CONCLUSION: Available evidence suggests that there is no significant reduction in local recurrence rates or improved survival from LPLND to the current treatment modalities. Further studies are required to define the role of lateral pelvic lymph node dissection in low rectal cancer.

Treatment of Uncomplicated Acute Diverticulitis Without Antibiotics: A Systematic Review and Meta-analysis.

BACKGROUND: Despite low-quality and conflicting evidence, the Association of Coloproctology of Great Britain and Ireland recommends the routine use of antibiotics in the treatment of uncomplicated acute diverticulitis. Recent studies have shown that treatment without antibiotics did not prolong recovery. Some new guidelines currently recommend selective use of antibiotics. OBJECTIVE: The purpose of this study was to compare the safety, effectiveness, and outcomes in treating uncomplicated acute diverticulitis without antibiotics with treatment with antibiotics. DATA SOURCES: PubMed, Embase, Clinicaltrials.gov, and the Cochrane Library were searched with the key words antibiotics and diverticulitis. STUDY SELECTION: All studies published in English on treating uncomplicated acute diverticulitis without antibiotics and containing >20 individuals were included. INTERVENTION: Treatment without antibiotics versus treatment with antibiotics were compared. MAIN OUTCOME MEASURES: The primary outcome was the percentage of patients requiring additional treatment or intervention to settle during the initial episode. The secondary outcomes were duration of hospital stay, rate of readmission or deferred admission, need for surgical or radiological intervention, recurrence, and complication. RESULTS: Search yielded 1164 studies. Nine studies were eligible and included in the meta-analysis, composed of 2505 patients, including 1663 treated without antibiotics and 842 treated with an antibiotic. The no-antibiotics group had a significantly shorter hospital stay (mean difference = -0.68; p = 0.04). There was no significant difference in the percentage of patients requiring additional treatment or intervention to settle during the initial episode (5.3% vs 3.6%; risk ratio = 1.48; p = 0.28), rate of readmission or deferred admission (risk ratio = 1.17; p = 0.26), need for surgical or radiological intervention (risk ratio = 0.61; p = 0.34), recurrence (risk ratio = 0.83; p = 0.21), and complications (risk ratio = 0.70-1.18; p = 0.67-0.91). LIMITATIONS: Only a limited number of studies were available, and they were of variable qualities. CONCLUSIONS: Treatment of uncomplicated acute diverticulitis without antibiotics is associated with a significantly shorter hospital stay. There is no significant difference in the percentage of patients requiring additional treatment or intervention to settle in the initial episode, rate of readmission or deferred admission, need for surgical or radiological intervention, recurrence, or complications.

'Watch and wait' in rectal cancer: summary of the current evidence.

BACKGROUND: The management of rectal cancer has evolved considerably over the last few decades with increasing use of neoadjuvant chemoradiotherapy (nCRT). Complete clinical response (cCR) and even complete pathological response (pCR) have been noted in a proportion of patients who had surgery after nCRT. This raises the concern that we may have been 'over-treating' some of these patients and lead to an increasing interest in 'watch and wait' (W&W) approach for patients who had cCR to avoid the morbidity associated with rectal surgery. METHODS: A review of the literature in English pertaining to rectal cancer in the context of W&W, organ preservation and active surveillance. RESULTS: Evidence available to support W&W approach comes from non-randomised controlled trials (RCTs) with no current consensus on patients' selection criteria, lack of viable predictors of both cCR and pCR and lack of universal definitions of cCR and pCR. Also, there is no agreed protocol for disease surveillance. CONCLUSION: Even though there has been increasing reports on the outcomes of W&W in rectal cancer, the current evidence cannot support its routine use in clinical practice. This approach should be used in clinical trials settings or after thorough counselling with the patient on the outcomes of various treatment options.

The role of oral antibiotics prophylaxis in prevention of surgical site infection in colorectal surgery.

BACKGROUND: Surgical site infection (SSI) continues to be a challenge in colorectal surgery. Over the years, various modalities have been used in an attempt to reduce SSI risk in elective colorectal surgery, which include mechanical bowel preparation before surgery, oral antibiotics and intravenous antibiotic prophylaxis at induction of surgery. Even though IV antibiotics have become standard practice, there has been a debate on the exact role of oral antibiotics. AIM: The primary aim was to identify the role of oral antibiotics in reduction of SSI in elective colorectal surgery. The secondary aim was to explore any potential benefit in the use of mechanical bowel preparation (MBP) in relation to SSI in elective colorectal surgery. METHODS: Medline, Embase and the Cochrane Library were searched. Any randomised controlled trials (RCTs) or cohort studies after 1980, which investigated the effectiveness of oral antibiotic prophylaxis and/or MBP in preventing SSIs in elective colorectal surgery were included. RESULTS: Twenty-three RCTs and eight cohorts were included. The results indicate a statistically significant advantage in preventing SSIs with the combined usage of oral and systemic antibiotic prophylaxis. Furthermore, our analysis of the cohort studies shows no benefits in the use of MBP in prevention of SSIs. CONCLUSIONS: The addition of oral antibiotics to systemic antibiotics could potentially reduce the risk of SSIs in elective colorectal surgery. Additionally, MBP does not seem to provide a clear benefit with regard to SSI prevention.

Does robotic rectal cancer surgery offer improved early postoperative outcomes?

BACKGROUND: Laparoscopic rectal surgery continues to be challenging, especially in low rectal cancers, because the technique has several limitations. Robotic rectal surgery could potentially address these limitations. However, it still remains unclear whether robotic surgery should be accepted as the new standard treatment in rectal cancer surgery. OBJECTIVE: The aim of this study is to provide a comprehensive and critical analysis of the available literature to assess if robotic rectal surgery offers improved early postoperative outcomes in comparison with standard laparoscopic rectal surgery. DATA SOURCES: A systematic review was conducted following the search of electronic databases (PubMed, Science Direct, Google Scholar) for the period 2007 to 2011 by using the key words "rectal surgery," "laparoscopic," "robotic." STUDY SELECTION: All studies reporting outcomes on laparoscopic and robotic resection for extraperitoneal and intraperitoneal rectal cancer were included in the review process; all studies on colonic cancer and benign disease were excluded. INTERVENTIONS: A comparison was conducted of robotic vs standard laparoscopic rectal cancer surgery. MAIN OUTCOME MEASURES: The primary outcome measured was the assessment of whether robotic rectal cancer surgery provides improved short-term outcomes in comparison with standard laparoscopic rectal surgery. RESULTS: Robotic rectal surgery was associated with increased cost and operating time, but lower conversion rates, even in obese individuals, distal rectal tumors, and patients who had preoperative chemoradiotherapy regardless of the experience of the surgeon. There is also marginally better outcome in anastomotic leak rates, circumferential resection margin positivity, and perseveration of autonomic function, but this did not reach statistical significance. LIMITATIONS: This review has some limitations because it relies on the analysis of data collected from various nonrandomized controlled trials with variable quality and different methodology. CONCLUSION: The current evidence suggests that robotic rectal surgery could potentially offer better short-term outcomes especially when applied in selected patients. Obesity, male sex, preoperative radiotherapy, and tumors in the lower two-thirds of the rectum may represent selection criteria for robotic surgery to justify its increased cost.

Robotic colonic surgery: is it advisable to commence a new learning curve?

BACKGROUND: Robotic surgery has potential advantages in rectal and pelvic surgery, in which the dissection is performed within a confined operative field. However, the position of robotic colonic surgery remains largely undefined with limited insight of whether it offers any potential advantages over open or laparoscopic colon surgery. OBJECTIVES: The aim of this systematic review was to compare the short-term outcomes of the published robotic colonic surgery with those of laparoscopic colonic surgery. DATA SOURCES: The search was performed in September 2012 with the use of PubMed, MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials. The search terms used were "colorectal," "colon," "colectomy," and "robotic/robot." DATA SELECTION: All studies reporting outcomes on robotic colonic resection were included in the review process. Colonic robotic data were compared with data on the short-term outcomes of laparoscopic colonic surgery from a Cochrane review and 4 main randomized controlled trials. INTERVENTIONS: A comparison was conducted of robotic colonic surgery vs standard laparoscopic colonic surgery. MAIN OUTCOME MEASURES: Short-term outcomes and the complication profile of colonic robotic surgery were compared with conventional multiple-port laparoscopic colonic surgery. RESULTS: Fifteen robotic colonic surgery articles with 351 patients (173 males, 178 females) were considered for analysis. The operative time and financial cost of robotic colonic surgery was greater than standard laparoscopic colonic surgery with comparable short-term outcomes and early postoperative complications profile. CONCLUSIONS: The present evidence on robotic colonic surgery has shown both feasibility and a safety profile comparable to standard laparoscopic colonic surgery. However, operative time and cost were greater in robotic colonic surgery, with no difference in the length of postoperative stay in comparison with standard laparoscopic colonic surgery. Whether the general surgical community should embark on a new learning curve for robotic colonic surgery can only be answered in the light of future studies.

Lateral pelvic lymph node dissection in the management of locally advanced low rectal cancer: Summary of the current evidence.

Lateral pelvic lymph nodes (LPLN) are a major site for local recurrence following curative resection for low locally advanced rectal cancer. Ongoing advances in imaging techniques have improved predicting LPLN metastasis (LPLNM) during pre-operative staging. However, there is ongoing debate on optimal management of this subgroup of patients with variation between guidance of different societies. In Japan, LPLNM is considered as local disease and addressed by lateral pelvic node dissection (LPLND) in addition to total mesorectal excision (TME). However, in the west, LPLNM is considered as metastatic disease and those patients are offered neoadjuvant chemoradiotherapy (nCRT) followed by TME surgery. The potential surgical risks and morbidity associated with LPLND as well as the uncertainty of the oncological outcome have raised the concern that patients with locally advanced low rectal cancer with LPLNM could be over or under-treated. A comprehensive review of literature was performed, summarizing the current evidence on available modalities for predicting LPLNM, the role of LPLND in the management of advanced low rectal cancer and the available surgical approaches with their impact on surgical and oncological outcomes. LPLND is associated with increased operative time, blood loss and post-operative morbidity. The potential benefits for local disease control and survival still awaits high quality studies. There has been increasing number of reports of the use minimally invasive approaches in LPLND in an attempt to reduce post-operative complications. There is need for high quality evidence to define the role of LPLND in management of patients with advanced low rectal cancer.

The effects of enteral immunonutrition in upper gastrointestinal surgery: A systematic review and meta-analysis.

AIM: The beneficial of immunonutrition on overall morbidity and mortality remains uncertain. We undertook a systematic review to evaluate the effects of immune-enhancing enteral nutrition (IEN) in upper gastrointestinal (GI) surgery. METHODS: Main electronic databases [MEDLINE via Pubmed, EMBASE, Scopus, Web of Knowledge, Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Library, and clinical trial registry (ClinicalTrial.gov)] were searched for studies reported clinical outcomes comparing standard enteral nutrition (SEN) and immunonutrition (IEN). The systematic review was conducted in accordance with the PRISMA guidelines and meta-analysis was analysed using fixed and random-effects models. RESULTS: Nineteen RCTs with a total of 2016 patients (1017 IEN and 999 SEN) were included in the final pooled analysis. The ratio of patients underwent oesophagectomy:gastrectomy:pancreatectomy was 2.2:1.2:1.0. IEN, when administered post-operatively, was associated with a significantly lower risk of wound infection (risk ratio (RR) 0.59, 95% confidence interval (CI) 0.40 to 0.88; p = 0.009) and shorter length of hospital stay (MD -2.92 days, 95% CI -3.89 to -1.95; p < 0.00001). No significant differences in other post-operative morbidities of interest (e.g. anastomotic leak and pulmonary infection) and mortality between the two groups were identified. CONCLUSIONS: Overall, our analysis found that IEN decreases wound infection rates and reduces length of stay. It should be recommended as routine nutritional support as part of the Enhanced Recovery after Surgery (ERAS) programmes for upper GI Surgery.

Low vs. standard dose computed tomography in suspected acute appendicitis: Is it time for a change?

BACKGROUND: Clinical diagnosis is accurate in only 80% of patients with suspected appendicitis with negative appendectomy rates of up to 21%. In the UK the use of standard-dose CT (SDCT) is conservative due to concerns over radiation exposure and resource implications. The use of low dose computer tomography (LDCT) instead of standard dose computer tomography (SDCT) may partially address these concerns. AIM: To compare LDCT and SDCT in the diagnosis of appendicitis. METHODS: A literature search of the EMBASE and MEDLINE databases in July 2015 was conducted using the keywords 'low dose CT' and 'appendicitis'. Data were analysed and p values calculated using the Chi-square test. P values less than 0.05 were considered to be significant. RESULTS: LDCT (1.2-5.3 mSv) was not inferior to SDCT (5.2-10.2 mSv) in the diagnosis of acute appendicitis and proposing alternative diagnoses. SDCT was superior to LDCT in the negative predictive value of diagnosis of appendiceal perforation. There was no significant difference between LDCT and SDCT in negative appendectomy rate, appendiceal perforation rate and the need for additional imaging. CONCLUSION: LDCT is not inferior to SDCT in the diagnosis of acute appendicitis and proposing alternative diagnoses. Further studies are recommended to further assess the potential role of LDCT & its cost effectiveness. Its use may improve the current management of patients with suspected acute appendicitis.

Exact analytical solution of the peristaltic nanofluids flow in an asymmetric channel with flexible walls and slip condition: application to the cancer treatment.

In the cancer treatment, magnetic nanoparticles are injected into the blood vessel nearest to the cancer's tissues. The dynamic of these nanoparticles occurs under the action of the peristaltic waves generated on the flexible walls of the blood vessel. Studying such nanofluid flow under this action is therefore useful in treating tissues of the cancer. In this paper, the mathematical model describing the slip peristaltic flow of nanofluid was analytically investigated. Exact expressions were deduced for the temperature distribution and nano-particle concentration. In addition, the effects of the slip, thermophoresis, and Brownian motion parameters on the temperature and nano-particle concentration profiles were discussed and further compared with other approximate results in the literatures. In particular, these results have been obtained at the same values of the physical examined parameters that was considered in Akbar et al., "Peristaltic flow of a nanofluid with slip effects," 2012. The results reveal that remarkable differences are detected between the exact current results and those approximately obtained in the literatures for behaviour of the temperature profile and nano-particles concentration. Accordingly, the current analysis and results are considered as optimal and therefore may be taken as a base for any future comparisons.

Is routine blood cross-matching necessary in elective laparoscopic colorectal surgery?

BACKGROUND: Routine pre-operative cross-matching of two units of packed red cells (PRC) is current practice in most hospitals for patients undergoing elective laparoscopic colorectal surgery (LCS). AIMS: To determine the usage of PRC in patients undergoing elective LCS & its cost implications. METHODS: Retrospective analysis of 116 consecutive laparoscopic colorectal resections under the care of 2 consultant surgeons. RESULTS: Surgical procedures were anterior resection (31.9%; n = 37), right hemicolectomy (22.4%; n = 26), sigmoid colectomy (22.4%; n-26), subtotal colectomy (7.8%; n = 9), APR (4.3%; n = 5), panproctocolectomy (3.4%; n = 4), completion proctectomy (1.7%, n = 2), left hemicolectomy (0.9%, n = 1), total colectomy (0.9%; n = 1) & resection rectopexy (0.9%; n = 1). The median age was 65 years, 58% female. The median pre-operative haemoglobin was 131 g/L, median blood loss 100 ml and median post-operative haemoglobin 111.5 g/L. Eleven cases were converted. Three patients required perioperative blood transfusion, 2 of whom underwent open conversion. The cost of carrying out a group & save (G&S) in our hospital is £40.60 excluding laboratory staff labour cost. A 2 unit cross-match costs £294.60. There is potential for substantial cost savings with change of practice to G&S only. CONCLUSION: G&S is sufficient to allow safe & cost-effective operative practice in laparoscopic colorectal surgery.

Endometriosis in the canal of Nuck hydrocele: An unusual presentation.

The authors describe an unusual rare presentation of endometriosis in a hydrocoele of the canal of Nuck. A 43-year-old lady presented with a swelling in her right groin associated with mild discomfort. Examination revealed a cystic swelling in the groin for which she underwent an exploration and excision of the swelling. Surgery revealed a hydrocele of the canal of Nuck which was confirmed histologically. The unusual presentation of endometriosis in the sac was confirmed immunocytochemically.