Systematic review and meta-analysis of randomized controlled trials evaluating the effect of the level of ligation of inferior mesenteric artery on functional outcomes in rectal cancer surgery

Development and validation of machine learning models for predicting no. 253 lymph node metastasis in left-sided colorectal cancer using clinical and CT-based radiomic features

BACKGROUND

The appropriate ligation level of the inferior mesenteric artery (IMA) in left-sided colorectal cancer (CRC) surgery is debated, with metastasis in No. 253 lymph node (No. 253 LN) being a key determining factor. This study aimed to develop a machine learning model for predicting metastasis in No. 253 LN.

METHODS

We retrospectively collected clinical data from 2,118 patients with left-sided CRC and contrast-enhanced CT images from 310 of these patients. From this data, a test set, a training set, and a temporal validation set were constructed. Logistic regression models were used to develop a clinical model, a CT model, and a radiomics model, which were then integrated into a combined model using logical rules. Finally, these models were evaluated using metrics such as the area under the receiver operating characteristic curve (AUC), precision-recall (PR) curves, decision curve analysis (DCA), net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

RESULTS

A clinical model, a CT model, and a radiomics model were constructed using univariate logistic regression. A combined model was developed by integrating the clinical, CT, and radiomics models, with positivity defined as all three models being positive at a 90% sensitivity threshold. The clinical model included six predictive factors: tumor site, endoscopic obstruction, CEA levels, growth type, differentiation grade, and pathological classification. The CT model utilized largest lymph node average CT value, short-axis diameter and long-axis diameter. The radiomics model incorporated maximum gray level intensity within the region of interest, large area high gray level emphasis, small area high gray level emphasis and surface area to volume ratio. In the test set, the AUCs for the clinical, CT, radiomics, and combined models were 0.694, 0.663, 0.72, and 0.663, respectively, while in the temporal validation set, they were 0.743, 0.629, 0.716, and 0.8. Specifically, the combined model demonstrated a sensitivity of 0.8 and a specificity of 0.8 in the temporal validation set. By comparing the PR and DCA curves, the combined model demonstrated better performance. Additionally, the combined model showed moderate improvements in INR and IDI compared to other models.

CONCLUSION

A clinical and CT-based radiomics model shows promise in predicting No. 253 LN metastasis in left-sided CRC and provides insights for optimizing IMA ligation strategies.

Truly Inevitable-Our Perspective on the Complications After Surgery for Rectal Cancer

Rectal cancer is one of the most common malignancies in the GI tract. Although recent technology and treatments are available today, complications are still there. The focus of this study is to draw attention towards the important complications and their management options in rectal cancer surgeries. Retrospective study of 57 patients diagnosed and operated with rectal cancer between 2012 and 2022 using questionnaire data. 21.05% developed complications following surgery for rectal cancer including SSI, LARS, anastomosis leak, and stomal stenosis. LARS was seen in 26.31% out of the 19 patients involved in the study (LAR + ULAR) of which 80% had minor LARS scores and 20% had major LARS scores. In LARS, 80% had received long-term chemoradiotherapy in a neoadjuvant setting. The study revealed a rising trend of rectal cancer in young individuals (35.08%). Complications are an inevitable part of rectal cancer surgery even with recent technology. Use of long-course radiotherapy in neoadjuvant settings and LAR and ULAR may improve sphincter preservation with the risk of increasing incidence of low anterior resection syndrome, and anastomosis leak should be used cautiously with proper patient selection.

The Diagnosis and Evolution of Patients with LARS Syndrome: A Five-Year Retrospective Study from a Single Surgery Unit

OBJECTIVES

The aim of the study was to assess the diagnosis and evolution of low anterior rectal resection syndrome (LARS) in patients admitted to a tertiary surgical center in Romania.

MATERIALS AND METHODS

From 120 patients initially included in the analysis, after applying the exclusion criteria, we selected 102 patients diagnosed and operated on for neoplasm of the upper, middle, and lower rectum for which resection and excision (partial or total) of mesorectum was associated. All the patients we treated in the general surgery department of the County Emergency Hospital of Craiova within a time frame of 5 years (1 October 2017-1 September 2022), and all experienced at least one symptom associated with LARS. The group included 68 men and 34 women aged between 35 and 88, who were followed-up for at least 2 years. Patients with progression of neoplastic disease, with advanced neurological disease, and those who died less than 2 years after surgery were excluded.

RESULTS

The overall incidence varied by gender, site of the tumor (requiring a certain type of surgery), and anastomotic complications, and it was directly proportional to the time interval between resection and restoration of continuity of digestion.

CONCLUSIONS

Obesity, size of the remaining rectum, total excision of the mesorectum, anastomotic complications, and prolonged ileostomy time are cofactors in the etiology of LARS. The LARS score decreased in most patients during the 2-year follow-up, although there were a small number of patients in whom the decrease was insignificant. The persistence of major LARS at 6 months after surgery may predict the need for a definitive colostomy.

High Ligation of the Inferior Mesenteric Artery in Left-Sided Colon and Rectal Cancer Resection: Rates of Success and Outcomes

BACKGROUND

High ligation of the inferior mesenteric artery, defined as ligation before the takeoff of the left colic artery, is often described as the gold standard in low left-sided colon and rectal cancer surgery. The aim of this study is to quantify the rate of ligation at the described level at a single academic center. Additionally, we examined the relationship between level of ligation and cancer-related outcomes.

METHODS

This retrospective cohort study included patients ages 18 and over with low left-sided colon, rectal, and anal cancers undergoing surgical resection. Radiographic evidence of high ligation was defined as ligation of the inferior mesenteric artery before the takeoff of the left colic artery. Patients with and without radiographic evidence of high ligation on CT were compared. Secondary outcomes include lymph node yield and positivity, need for adjuvant therapy, and time from surgery to adjuvant therapy.

RESULTS

169 patients (54% male) were included in the study. 61.5% of operative reports described high ligation of the IMA. There was radiographic evidence of high ligation in 55.6% of total patients and in 70.2% of patients where high ligation was intended. There was no significant difference in surgeon experience, surgical procedure, or surgical approach. There was no difference in lymph node yield, time to adjuvant chemotherapy, or recurrence rates.

CONCLUSION

This study demonstrates good technical success rate of high ligation of the inferior mesenteric artery but shows no difference in short-term patient-measured outcomes between high and low ligation (or successful and unsuccessful high ligation).

The Atlas of the Inferior Mesenteric Artery and Vein under Maximum-Intensity Projection and Three-Dimensional Reconstruction View

(1) Background: Understanding vascular patterns is crucial for minimizing bleeding and operating time in colorectal surgeries. This study aimed to develop an anatomical atlas of the inferior mesenteric artery (IMA) and vein (IMV). (2) Methods: A total of 521 patients with left-sided colorectal cancer were included. IMA and IMV patterns were identified using maximum-intensity projection (MIP) and three-dimensional (3D) reconstruction techniques. The accuracy of these techniques was assessed by comparing them with surgical videos. We compared the amount of bleeding and operating time for IMA ligation across different IMA types. (3) Results: Most patients (45.7%) were classified as type I IMA, followed by type II (20.7%), type III (22.6%), and type IV (3.5%). Newly identified type V and type VI patterns were found in 6.5% and 1% of patients, respectively. Of the IMVs, 49.9% drained into the superior mesenteric vein (SMV), 38.4% drained into the splenic vein (SPV), 9.4% drained into the SMV-SPV junction, and only 2.3% drained into the first jejunal vein (J1V). Above the root of the left colic artery (LCA), 13.1% of IMVs had no branches, 50.1% had one, 30.1% had two, and 6.7% had three or more branches. Two patients had two main IMV branches, and ten had IMVs at the edge of the mesocolon with small branches. At the IMA root, 37.2% of LCAs overlapped with the IMV, with 34.0% being lateral, 16.9% distal, 8.7% medial, and both the marginal type of IMV and the persistent descending mesocolon (PDM) type represented 1.4%. MIP had an accuracy of 98.43%, and 3D reconstruction had an accuracy of 100%. Blood loss and operating time were significantly higher in the complex group compared to the simple group for IMA ligation (p < 0.001). (4) Conclusions: A comprehensive anatomical atlas of the IMA and IMV was provided. Complex IMA patterns were associated with increased bleeding and operating time.

Elderly Rectal Cancer: An Updated Review

PURPOSE OF REVIEW

Treatment of rectal cancer patients of advanced age should be modulated by life expectancy and tolerance. Due to the rapid advance of this field, we aim to conduct an updated review of this topic.

RECENT FINDINGS

The field of elderly rectal cancer has advanced a lot. This review covers all the treatment aspects of elderly rectal cancer, including the prognostic factor, surgery, radiotherapy, chemotherapy, and palliative treatment. We also provide the future aspect of the management of elderly rectal cancer. The advancement of prognostic factor research, surgery, radiotherapy, chemotherapy, and palliative treatment has made the care of elderly rectal cancer patients better. The future of these fields should focus on the definition of the elderly and the application of particle therapy.

Survivorship in Early-Stage Rectal Cancer Patients Who Have Received Combined Modality Therapy

Survival rates in early-stage rectal cancer patients have increased over the past few decades. Societies such as the National Comprehensive Cancer Network (NCCN), American Cancer Society (ACS), American Society of Clinical Oncology (ASCO), and European Society of Medical Oncology (ESMO) have proposed guidelines related to cancer survivorship care including formal recommendations to address the needs in early-stage rectal cancer survivors. These guidelines, in addition to new clinical research findings in survivorship will be reviewed, specifically looking at physical, psychosocial, and financial concerns in rectal cancer survivorship.

Inferior mesenteric artery ligation level in rectal cancer surgery: still no answer-a systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis is to summarize the current scientific evidence regarding the impact of the level of inferior mesenteric artery (IMA) ligation on post-operative and oncological outcomes in rectal cancer surgery.

METHODS

We conducted a systematic review of the literature up to 06 September 2022. Included were RCTs that compared patients who underwent high (HL) vs. anterior (LL) IMA ligation for resection of rectal cancer. The literature search was performed on Medline/PubMed, Scopus, and the Web of Science without any language restrictions. The primary endpoint was overall anastomotic leakage (AL). Secondary endpoints were oncological outcomes, intraoperative complications, urogenital functional outcomes, and length of hospital stay.

RESULTS

Eleven RCTs (1331 patients) were included. The overall rate of AL was lower in the LL group, but the difference was not statistically significant (RR 1.43, 95% CI 0.95 to 2.96). The overall number of harvested lymph nodes was higher in the LL group, but the difference was not statistically significant (MD 0.93, 95% CI - 2.21 to 0.34). The number of lymph nodes harvested was assessed in 256 patients, and all had a laparoscopic procedure. The number of lymph nodes was higher when LL was associated with lymphadenectomy of the vascular root than when IMA was ligated at its origin, but there the difference was not statistically significant (MD - 0.37, 95% CI - 1.00 to 0.26). Overall survival at 5 years was slightly better in the LL group, but the difference was not statistically significant (RR 0.98, 95% CI 0.93 to 1.05). Disease-free survival at 5 years was higher in the LL group, but the difference was not statistically significant (RR 0.97, 95% CI 0.89 to 1.04).

CONCLUSIONS

There is no evidence to support HL or LL according to results in terms of AL or oncologic outcome. Moreover, there is not enough evidence to determine the impact of the level of IMA ligation on functional outcomes. The level of IMA ligation should be chosen case by case based on expected functional and oncological outcomes.

Management of Low Anterior Resection Syndrome (LARS) Following Resection for Rectal Cancer

INTRODUCTION

A total of 60-80% of patients undergoing rectal resection (mostly as a treatment for rectal cancer) suffer from a variety of partly severe functional problems despite preservation of the anal sphincter. These patients are summarized under the term low anterior resection syndrome (LARS). Preoperative radiotherapy, vascular dissection and surgical excision of the low rectum and mesorectum lead, alone or all together, to a significant impairment of colonic and (neo-) rectal motility. This results in a variety of symptoms (multiple defecation episodes, recurrent episodes of urge, clustering, incontinence, etc.) which are associated with severe impairment of quality of life (QOL).

METHODS

This narrative review summarizes the present state of knowledge regarding the pathophysiology of LARS as well as the evidence for the available treatment options to control the symptoms resulting from this condition.

RESULTS

A review of the literature (Medline, Pubmed) reveals a variety of treatment options available to control symptoms of LARS. Medical therapy, with or without dietary modification, shows only a modest effect. Pelvic floor rehabilitation consisting of muscle exercise techniques as well as biofeedback training has been associated with improvement in LARS scores and incontinence, albeit with limited scientific evidence. Transanal irrigation (TAI) has gained interest as a treatment modality for patients with LARS due to an increasing number of promising data from recently published studies. Despite this promising observation, open questions about still-unclear issues of TAI remain under debate. Neuromodulation has been applied in LARS only in a few studies with small numbers of patients and partly conflicting results.

CONCLUSION

LARS is a frequent problem after sphincter-preserving rectal surgery and leads to a marked impairment of QOL. Due to the large number of patients suffering from this condition, mandatory identification, as well as treatment of affected patients, must be considered during surgical as well as oncological follow-up. The use of a standardized treatment algorithm will lead to sufficient control of symptoms and a high probability of a marked improvement in QOL.

Lower gastrointestinal function after surgery for deep endometriosis: A prospective cohort study

OBJECTIVE

To prospectively compare long-term lower gastrointestinal function before and after laparoscopic surgery for deep endometriosis (DE).

METHODS

In this prospective observational study we followed 149 patients with confirmed DE who were treated surgically. Patients completed the International Consultation on Incontinence Questionnaire Anal Incontinence Symptoms and Quality of Life Module (ICIQ-B) before surgery, and 6 weeks, 6 months, and 12 months after surgery. Bowel pattern, bowel control, and bowel impact on quality of life summary scores were compared before and after surgery.

RESULTS

Bowel pattern score showed an increasing improvement at all time points after surgery, from a mean pre-operation score of 4.8 ± 2.0 to 4.4 ± 1.8 at 6 weeks, 4.2 ± 1.8 at 6 months, and 4.2 ± 1.2 at 12 months. Bowel impact on quality of life significantly improved from pre-surgery mean score of 5.5 ± 6.0 to 4.2 ± 5.5 at 6 weeks and 4.4 ± 5.4 at 6 months. Direct lower gastrointestinal endometriosis involvement and worse initial function were associated with larger improvements in scores following surgery.

CONCLUSIONS

Lower gastrointestinal function significantly improved after surgical treatment of DE. Further research is needed to confirm our findings and to better characterize the sub-groups of patients for whom surgery will have a beneficial effect on their bowel function.

The role of colonic motility in low anterior resection syndrome

Low anterior resection syndrome (LARS) describes the symptoms and experiences of bowel dysfunction experienced by patients after rectal cancer surgery. LARS is a complex and multifactorial syndrome exacerbated by factors such as low anastomotic height, defunctioning of the colon and neorectum, and radiotherapy. There has recently been growing awareness and understanding regarding the role of colonic motility as a contributing mechanism for LARS. It is well established that rectosigmoid motility serves an important role in coordinating rectal filling and maintaining continence. Resection of the rectosigmoid may therefore contribute to LARS through altered distal colonic and neorectal motility. This review evaluates the role of colonic motility within the broader pathophysiology of LARS and outlines future directions of research needed to enable targeted therapy for specific LARS phenotypes.

High Versus Low Ligation of the Inferior Mesenteric Artery in Colorectal Cancer Surgery: A Systematic Review and Meta-Analysis

Background and Objectives: This study aimed to compare the effects of high ligation (HL) versus low ligation (LL) in colorectal cancer surgery. Materials and Methods: We performed a comprehensive search using multiple databases (trial registries and ClinicalTrials.gov), other sources of grey literature, and conference proceedings, with no restrictions on the language or publication status, up until 10 March 2021. We included all parallel-group randomized controlled trials (RCTs) and considered cluster RCTs for inclusion. The risk of bias domains were "low risk," "high risk," or "unclear risk." We performed statistical analyses using a random-effects model and interpreted the results according to the Cochrane Handbook for Systematic Reviews of Interventions. We used the GRADE guidelines to rate the certainty of evidence (CoE) of the randomized controlled trials. Results: We found 12 studies (24 articles) from our search. We were very uncertain about the effects of HL on overall mortality, disease recurrence, cancer-specific mortality, postoperative mortality, and anastomotic leakage (very low CoE). There may be little to no difference between HL and LL in postoperative complications (low CoE). For short-term follow-up (within 6 months), HL may reduce defecatory function (constipation; low CoE). While HL and LL may have similar effects on sexual function in men, HL may reduce female sexual function compared with LL (low CoE). For long-term follow-up (beyond 6 months), HL may reduce defecatory function (constipation; low CoE). There were discrepancies in the effects regarding urinary dysfunction according to which questionnaire was used in the studies. HL may reduce male and female sexual function (low CoE). Conclusions: We are very uncertain about the effects of HL on survival outcomes, and there is no difference in the incidence of postoperative complications between HL and LL. More rigorous RCTs are necessary to evaluate the effect of HL and LL on functional outcomes.