High ligation of the inferior mesenteric artery during sigmoid colon and rectal cancer surgery increases the risk of anastomotic leakage: a meta-analysis

Low ligation of the inferior mesenteric artery in robotic mid-low rectal cancer surgery: a comparative study from a single-center

Laparoscopic total mesorectal excision is the main surgical approach for treating rectal cancer, but there is still no clear consensus on the issue of low ligation of the inferior mesenteric artery during the procedure. Robotic surgery has been shown to have certain advantages over laparoscopic surgery in multiple studies, but further research is needed to better understand the outcomes of robotic surgery in the context of low ligation procedures. In this study, we included 1590 patients with mid-low rectal cancer. Among them, 942 patients underwent low ligation surgery (LL), divided into 138 in the robotic group and 804 in the laparoscopic group. The high ligation surgery (HL) group consisted of 648 patients. The results of LL vs HL showed that the LL group had faster bowel movement recovery (P = 0.003), lower anastomotic leak rate (P = 0.032), and lower International Prostate Symptom Score (IPSS) at 6 months postoperatively (P < 0.001). The results of Rob-LL vs Lap-LL showed that the Rob-LL group had longer operative time (P < 0.001), less blood loss (P = 0.001), more lymph nodes retrieved (P = 0.045), and lower Wexner score at 2 weeks postoperatively (P = 0.029). The concept of low ligation of the inferior mesenteric artery is a promising surgical approach that can accelerate the patient's functional recovery. When combined with robotic technology, it may offer more benefits than laparoscopic techniques.

Cadaveric Study of Colon-Lengthening Maneuvers After Sigmoidectomy

BACKGROUND

Creation of a tension-free colorectal anastomosis after left colon resection or low anterior resection is a key requirement for technical success. The relative contribution of each of a series of known lengthening maneuvers remains incompletely characterized.

OBJECTIVE

The aim of this study was to compare technical procedures for lengthening of the left colon before rectal anastomosis.

DESIGN

A series of lengthening maneuvers was performed on 15 fresh cadavers. Mean distance gained was measured for each successive maneuver, including 1) high inferior mesenteric artery ligation, 2) splenic flexure takedown, and 3) high inferior mesenteric vein ligation by the ligament of Treitz.

SETTING

Cadaveric study.

MAIN OUTCOME MEASURES

The premobilization and postmobilization position of the proximal colonic end was measured relative to the inferior edge of the sacral promontory. Measurements of the colonic length relative to the sacral promontory were taken after each mobilization maneuver. The inferior mesenteric artery, sigmoid colon, and rectum specimen lengths were measured. The distance from the inferior border of the sacral promontory to the pelvic floor was measured along the sacral curvature.

RESULTS

Mean sigmoid colon resection length was 34.7 ± 11.1 cm. Before any lengthening, baseline reach was -1.3 ± 4.2 cm from the sacral promontory. Inferior mesenteric artery ligation yielded an additional 11.5 ± 4.7 cm. Subsequent splenic flexure takedown added an additional 12.8 ± 9.6 cm. Finally, inferior mesenteric vein ligation added an additional 11.33 ± 6.9 cm, bringing the total colonic length to 35.7 ± 14.7 cm. BMI and weight negatively correlated with length gained.

LIMITATIONS

The study was limited by nature of being a cadaver study.

CONCLUSIONS

Stepwise lengthening maneuvers allow significant additional reach to allow a tension-free left colon to rectal anastomosis. See Video Abstract .

ESTUDIO CADAVRICO DE MANIOBRAS DE ALARGAMIENTO COLNICO TRAS UNA SIGMOIDECTOMA

ANTECEDENTES:La creación de una anastomosis colorrectal libre de tensión tras una resección de colon izquierdo o tras una resección anterior baja es un requisito clave para el éxito relacionado con la técnica quirúrgica. La relativa contribución de las diversas maniobras de alargamiento permanece caracterizada de manera incompleta.OBJETIVO:El propósito de este estudio fue la de comparar procedimientos técnicos de alargamiento del colon izquierdo previo a la anastomosis rectal.DISEÑO:Una serie de maniobras de alargamiento fueron realizados en 15 cadáveres frescos. La distancia promedio ganada fue medida para cada maniobra sucesiva, incluyendo (1) ligadura alta de la arteria mesentérica inferior, (2) descenso del ángulo esplénico, (3) ligadura alta de la vena mesentérica interior mediante el ligamento de Treitz.AJUSTES:Estudio cadavérico.PRINCIPALES MEDIDAS DE RESULTADO:La posición premobilizacion y postmobilizacion del extremo proximal del colon fue medido tomando en cuenta el borde inferior del promontorio sacro. Las mediciones de la longitud colónica en relación al sacro fueron tomadas luego de cada maniobra de movilización. Fueron tomadas así mismo las longitudes de la arteria mesentérica inferior, el colon sigmoides y recto. Las distancias desde el borde inferior del promontorio sacro al suelo pelvico fueron medidas a lo largo de la curvatura sacra.RESULTADOS:Average sigmoid colon resection length was 34.7 ± 11.1 cm. Prior to any lengthening, baseline reach was -1.3 ± 4.2 cm from the sacral promontory. Inferior mesenteric artery ligation yielded an additional 11.5 ± 4.7 cm. Subsequent splenic flexure takedown added an additional 12.8 ± 9.6 cm. Finally, inferior mesenteric vein ligation added an additional 11.33 ± 6.9 cm, bringing the total colonic length to 35.7 ± 14.7 cm. BMI and weight negatively correlated with length gained.LIMITACIONES:Este estudio tuvo como limitación la naturaleza de haber sido un estudio cadavérico.CONCLUSIONES:Maniobras de alargamiento permiten un alcance adicional significativo permitiendo de esta manera una anastomosis de colon izquierdo a recto libre de anastomosis. (Traducción-Dr Osvaldo Gauto ).

Short-term outcomes of short- and long-course chemoradiotherapy before total mesorectal excision for locally advanced rectal tumors: A single-center study in Taiwan utilizing propensity score matching

BACKGROUND

Locally advanced rectal tumors are typically treated with neoadjuvant chemoradiotherapy. Short-course chemoradiotherapy (SCRT, 2500 cGy in five fractions) is a convenient alternative to concurrent chemoradiotherapy with long-course radiotherapy (CCRT, 4500 cGy in 25 fractions) without sacrificing efficacy. We aimed to compare the short-term outcomes of SCRT and CCRT in patients with mid- and low- rectal tumors who underwent total mesorectal excision using real-world data.

METHODS

We retrospectively reviewed the data of patients with locally advanced rectal cancer who underwent radical resection after neoadjuvant chemoradiotherapy from 2011 to 2022. We analyzed the clinicopathological findings and prognostic factors for disease-free and overall survival in the SCRT and CCRT groups and compared the outcomes using propensity score matching.

RESULTS

Among the 66 patients in the two groups, no disparities were noted in the demographic features, pathological remission, or downstaging rates. Nonetheless, the SCRT group exhibited superior 3-year disease-free survival (81.8% vs 62.1%, p = 0.011), whereas the overall survival did not differ significantly between the two groups. The initial carcinoembryonic antigen (CEA) levels and neoadjuvant SCRT were associated with the recurrence rates [hazard ratio (HR) = 1.13-4.10; HR = 0.19-0.74], but the harvested lymph node count was not (HR = 0.51-1.97).

CONCLUSION

Among patients with locally advanced rectal cancer, SCRT combined with four cycles of FOLFOX was shown to enhance short-term disease-free survival. Factors impacting recurrence include the initial CEA level and SCRT, but not the harvested lymph node count.

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 implications of the anatomy of the nerves and vessels in the treatment of rectosigmoid endometriosis

Endometriosis is a common benign gynecological disease characterized by the presence of endometrial glands and stroma outside the uterus. It can be defined as endometrioma, superficial peritoneal endometriosis or deep infiltrating endometriosis (DIE) depending on the location and the depth of infiltration of the organs. In 5%-12% of cases, DIE affects the digestive tract, frequently involving the distal part of the sigmoid colon and rectum. Surgery is generally recommended in cases of obstructive symptoms and in cases with pain that is non-responsive to medical treatment. Selection of the most optimal surgical technique for the treatment of bowel endometriosis must consider different variables, including the number of lesions, eventual multifocal lesions, as well as length, width and grade of infiltration into the bowel wall. Except for some major and widely accepted indications regarding bowel resection, established international guidelines are not clear on when to employ a more conservative approach like rectal shaving or discoid resection, and when, instead, to opt for bowel resection. Damage to the pelvic autonomic nervous system may be avoided by detection of the middle rectal artery, where its relationship with female pelvic nerve fibers allows its use as an anatomical landmark. To reduce the risk of potential vascular and nervous complications related to bowel resection, a less invasive approach such as shaving or discoid resection can be considered as potential treatment options. Additionally, the middle rectal artery can be used as a reference point in cases of upper bowel resection, where a trans mesorectal technique should be preferred to prevent devascularization and denervation of the bowel segments not affected by the disease.

A nomogram for predicting lymph nodes metastasis at the inferior mesenteric artery in rectal cancer: a retrospective case-control study

According to past and current literature, metastasis of the lymph nodes at the inferior mesenteric artery (IMA-LN), also known as 253LN of colorectal cancer has been seldom investigated. To date, there are still controversies on whether the 253LN need to be routinely cleaned. Using specific criteria, 347 patients who underwent radical resection for rectal cancer between April 2019 and July 2022 were selected for the study. Logistic regression was used to determine the likelihood that a patient may suffer 253LN metastasis, and a nomogram for 253LN metastasis subsequently developed. The c-index and calibration curve were used to evaluate precision and discrimination in the nomogram, and the appropriateness of the final nomogram for the clinical setting determined using decision curve analysis (DCA). 253LN metastases appeared in the pathological specimens of 29 (8.4%) of the selected patients. Logistic regression showed that preoperative parameters including serum carcinoembryonic antigen (CEA) value ( > 5 ng / ml, OR = 2.894, P = 0.023), distance from anal margin (> 9 cm, OR = 2.406, P = 0.045) and degree of differentiation (poor, OR = 9.712, P < 0.001) were significantly associated with 253LN metastasis. A nomogram to predict 253LN metastasis in rectal cancer was developed and showed considerable discrimination and good precision (c-index = 0.750). Furthermore, DCA confirmed that the nomogram has some feasibility for the clinical environment. Clinicopathological and radiological patient data can be pivotal for making surgical decisions relating to 253LN metastasis. A nomogram was developed using this data, providing an objective method that can significantly improve prognoses in colorectal cancer.

Assessing anatomical variations of the inferior mesenteric artery via three-dimensional CT angiography and laparoscopic colorectal surgery: a retrospective observational study

To assess the anatomy of the inferior mesenteric artery (IMA) and its branches by reviewing laparoscopic left-sided colorectal cancer surgery videos and comparing them with preoperative three-dimensional computed tomography (3D-CT) angiography, to verify the accuracy of 3D-CT vascular reconstruction techniques. High-definition surgical videos and preoperative imaging data of 200 patients who underwent laparoscopic left-sided colorectal cancer surgery were analysed, and the alignment of the IMA and its branches in relation to the inferior mesenteric vein (IMV) was observed and summarized. The above two methods were used to measure the length of the IMA and its branches. Of 200 patients, 47.0% had the sigmoid arteries (SAs) arise from the common trunk with the superior rectal artery (SRA), and 30.5% had the SAs arise from the common trunk with the left colic artery (LCA). In 3.5% of patients, the SAs arising from both the LCA and SRA. The LCA, SA, and SRA emanated from the same point in 13.5% of patients, and the LCA was absent in 5.5% of patients. The range of D cm (IMA length measured by intraoperative silk thread) and d cm (IMA length measured by 3D-CT vascular reconstruction) in all cases was 1.84-6.62 cm and 1.85-6.52 cm, respectively, and there was a significant difference between them. (p < 0.001). The lengths between the intersection of the LCA and IMV measured intraoperatively were 0.64-4.29 cm, 0.87-4.35 cm, 1.32-4.28 cm and 1.65-3.69 cm in types 1A, 1B, 1C, and 2, respectively, and there was no significant difference between the groups (p = 0.994). There was only a significant difference in the length of the IMA between the 3D-CT vascular reconstruction and intraoperative observation data, which can provide guidance to surgeons in preoperative preparation.

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.

Venous Congestive Ischemic Colitis After Sigmoid Colectomy: A Case Report

Venous congestion is a possible cause of ischemic colitis following colorectal surgery. As such, congestive ischemic colitis should be considered in such cases where the mesenteric artery is preserved. Herein, we describe the case of a 73-year-old man who presented to the hospital with a two-week history of difficult defecation and frequent mucous stools and was subsequently diagnosed with refractory ischemic enterocolitis due to venous congestion. The patient had undergone resection of the sigmoid colon cancer with preservation of the inferior mesenteric artery 11 months before presentation. Contrast-enhanced abdominal computed tomography revealed edematous wall thickening on the anal side of the anastomosis. A colonoscopy revealed a normal mucosa extending from the anastomosis to the descending colon; however, mucosal swelling, erythema, and erosion were observed on the rectal side of the anastomosis. Based on these findings, he was diagnosed with ischemic colitis. After two months of ineffective conservative treatment, the patient underwent surgery. Ischemic colitis was diagnosed as venous congestion based on the histopathological examination. Preservation of the mesenteric artery may result in ischemic colitis due to an imbalance between the arterial and venous blood flow. Chronic ischemic colitis due to venous congestion should be considered in cases of mesenteric artery preservation to reduce anastomotic leakage.

Evaluation of the mesenteric arterial vasculature by computed tomography angiography and its implications for colorectal cancer surgery

Objective

To determine the branching patterns of the inferior mesenteric artery (IMA) and to describe the clinical applicability of computed tomography (CT) angiography in the evaluation of these vessels to facilitate the planning of colorectal cancer surgery.

Materials and Methods

We included 100 patients who underwent CT angiography of the abdomen and pelvis. The branching patterns of the IMA were examined and classified as type 1 (bifurcated), including 1A (sigmoid and left colic arteries arising from a common trunk), 1B (sigmoid and superior rectal arteries arising from a common trunk) and 1C (sigmoid arteries arising from both trunks); type 2 (trifurcated); and type 3 (no left colic branch).

Results

Among the 100 patients evaluated, we found the variant to be type 1A in 9%, type 1B in 47%, type 1C in 24%, type 2 in 16%, and type 3 in 4%.

Conclusion

Preoperative CT angiography for evaluating the IMA branching pattern could inform decisions regarding the surgical approach to colorectal cancer.

Risk factors for anastomotic stenosis after radical resection of rectal cancer: A systematic review and meta-analysis

Radical resection of rectal cancer is a safe and effective treatment, but there remain several complications related to anastomosis. We aimed to assess the risk factors and incidence of rectal anastomotic stenosis (AS) after rectal cancer resection. We conducted a systematic review and meta-analysis after searching PubMed, Embase, Web of Science, and Medline databases from inception until May 2023. Data are reported as the combined odds ratio (OR) for categorical variables and the weighted mean difference (WMD) for continuous variables. Six hundred and fifty-nine studies were retrieved, nine (3031 patients) of which were included in the meta-analysis. Young age (WMD = -3.09, P = 0.0002), male sex (OR = 1.53, P = 0.0002), smoking (OR = 1.54, P = 0.009), radiotherapy (OR = 2.34, P = 0.0002), protective stoma (OR = 2.88, P = 0.007), intersphincteric resection surgery (OR = 6.28, P = 0.05), anastomotic fistula (OR = 3.72, P = 0.003), and anastomotic distance (WMD = -3.11, P = 0.0006) were identified as factors that increased the risk of AS, while staple (OR = 0.39, P < 0.001) was a protective factor. The incidence of AS after rectal cancer resection was approximately 17% (95% CI: 13%-21%). We identified eight risk factors and one protective factor associated with AS after rectal cancer resection. These factors may be combined in future studies to develop a more comprehensive and accurate prediction model related to AS after rectal cancer resection.

Comparison of the short-term and long-term outcomes of three different types of inferior mesenteric artery ligation in left colonic and rectal cancers: a network meta-analysis

To perform a network meta-analysis of the literature to assess the short-term and long-term outcomes of three operations for left colon and rectal cancer. Electronic literature searches were performed in the PubMed, Web of Science, EMBASE, and Cochrane Central Register of Controlled Trials databases up to August 2022. A Bayesian network meta-analysis using R software, ADDIS, and Review Manager 5.4 was conducted to compare outcomes of high ligation of the inferior mesenteric artery(IMA),low ligation of the IMA with D2 dissection (LLD2), and low ligation of the IMA with D3 dissection (LLD3). Sensitivity analysis was applied to investigate the influence of each primary study on the final result of the meta-analysis. Asymmetry of data was estimated by using Egger's tests. Publication bias corrected by trimming and filling method. A total of 44 studies, 5 randomized clinical trials (RCTs) and 39 non-RCTs, were included in this meta-analysis. HL was associated with a higher risk of anastomotic leakage (HL vs. LLD2, OR = 1.35, 95% CI 1.13-3.25, P = 0.001; HL vs. LLD3, OR = 1.65, 95% CI 1.35-2.01, P < 0.001), and required a longer postoperative hospital stay (HL vs. LLD3, SMD = 0.28, 95%CI 0.09-0.48, P = 0.01).However HL showed an advantage in terms of operation time(HL vs. LLD3, SMD = - 0.13, 95%CI - 0.26 to 0.01, P = 0.04). LLD3 is most likely to rank best in terms of short-term and long-term outcomes after surgery for left colon and rectal cancer. Caution should be taken in the risk of anastomotic leakage when treating colorectal cancer with LLD2. HL, LLD2 and LLD3 provide similar overall survival rates for left colon and rectal cancer.

The value of ICG-guided left colon vascular variation and anatomical rules for the radical resection of proctosigmoid colon cancer

Objective

During laparoscopic radical resection for proctosigmoid colon cancer (PCC), surgeons could inadvertently damage the arteries when following the operation path.This study investigated the variations in left colon blood vessels in order to guide the scientific protection of the marginal artery (MA) during laparoscopic surgery for PCC.

Methods

Data from seven patients who underwent inferior mesenteric artery (IMA) angiography were included as imaging references to preliminarily explore the vascular structure and variation in the left colon. The clinical video data of 183 PCC patients were retrospectively analyzed to observe intraoperative MA injury. Meanwhile, a prospective cohort of 96 patients with the same disease underwent intraoperative indocyanine green (ICG) fluorescence imaging of the peripheral sigmoid artery network, the variation of marginal arteries was summarized, and the distance between vessels and the bowel was measured at different levels. Patients were divided into 'ICG group' and 'non-ICG group' according to whether ICG guidance was performed, and perioperative conditions were compared between the two groups. Taking the integrity of lymph node dissection into consideration, 18 patients underwent carbon nanonode tracing. This study was conducted under the standard consent and ethical approval of the Ethics Committee of our center.

Results

7 patients with IMA angiography shared some vascular structures, defined as 'Dangerous Triangle' and 'Secure Window'. Through intraoperative observation, the primary arch was typically located 4.2 (2.3-6.0) cm away from the intestinal canal, and 5.21% (5/96) patients had poor anastomosis at the primary arch. Moreover, secondary vascular arches (6.4 (4.6-10.0) cm from the intestinal wall) were observed in 38.54% of patients. MA injury was identified in 2 of 183 cases, and the ischemic bowel was timely dissected, whereas no such injury occurred during ICG fluorescenceguided surgery. Guided by carbon nanoparticles, the integrity of lymph node dissection can be maintained while preserving the secondary arch in all patients.

Conclusions

This study demonstrated the benefits of ICG guidance in protecting the intestinal blood supply in laparoscopic PCC surgery. By enhancing the understanding of primary and secondary vascular arches, secure windows, and dangerous triangles, surgeons can safely optimize the surgical path during surgery.

Influence of splenic flexure mobilization on postoperative and oncological outcomes following anterior resection

BACKGROUND

Splenic flexure mobilization (SFM) during anterior resection is often debated given its increased operative complexity and lack of clear data suggesting oncological benefit. This study aimed to compare postoperative complications and 3-year oncological outcomes in patients undergoing anterior resection with and without SFM.

METHODS

A retrospective single center observational study was performed. Notes review was performed for all patients undergoing anterior resection over a one-year period at a high-volume institution for sigmoid and rectal cancers. Anterior resections performed for benign disease or non-colorectal cancers were excluded.

RESULTS

One hundred seventeen patients were included and 49 (41.9%) underwent SFM. 75 (64.1%) cases were completed laparoscopically and 48 (41%) resulted in stoma formation. SFM significantly increased the risk of minor Clavien Dindo Grade 1 postoperative complications (18.4% vs. 5.9%, P=0.03), however, it had no impact on more major postoperative complications, including anastomotic leaks (4.2% vs. 7.1%, P=0.52). There were no significant differences in median total lymph node yield (21.0% vs. 21.1, P=0.57) or R0 resection margin (93.9% vs. 94.1%, P=0.96). There was a non-significant trend towards lower overall recurrence rates in the SFM group (10.2% vs. 19.1%, P=0.19).

CONCLUSIONS

In patients undergoing anterior resection for colorectal cancer, SFM provides no clear oncological benefit, but does increase the likelihood of minor postoperative complications. Whilst a trend towards lower overall recurrence rates was observed in the SFM group, this was not statistically significant. Therefore, SFM should be carefully considered on a case-by-case basis.

The impact of mismatch repair status and systemic inflammatory markers on radiological staging in colon cancer

OBJECTIVE

Mismatch repair (MMR) deficient (dMMR) colon cancer (CC) is distinct from MMR proficient (pMMR) CC, yet the impact of MMR status on radiological staging is unclear. The purpose of this study was to investigate how MMR status impacts CC CT staging.

METHODS

We retrospectively compared CT staging accuracy between dMMR and pMMR CC patients undergoing curative resection. Accuracy was assessed as individual tumour (T)/nodal (N) stages and as dichotomous "statuses" (T1/2 vs T3/4; N0 vs N1/2). Patient characteristics were analysed for factors to support staging.

RESULTS

There was no significant difference in overall staging accuracy between the dMMR (44 patients) and pMMR (57 patients) groups. dMMR tumours with incorrect N stage/"status" were more likely to be overstaged than pMMR tumours (90% vs 59%; p = 0.023 for "N status"). Platelet count, CRP and neutrophil count (AUC 0.76 (p = 0.0078), 0.75 (p = 0.034) and 0.70 (p = 0.044), respectively) were associated with "N status" in dMMR tumours.

CONCLUSION

Whilst overall staging accuracy was similar between groups, incorrectly N staged dMMR tumours were more likely to be overstaged than pMMR tumours, risking inappropriate surgical or neoadjuvant treatment. We describe novel relationships between several inflammatory markers and pathological "N status" in dMMR CC, which if integrated into routine practice may improve CT staging accuracy.

ADVANCES IN KNOWLEDGE

Compared to pMMR CC, dMMR CC is at significant risk of N overstaging. Platelet count, CRP and neutrophil count are higher in dMMR CC patients with nodal metastases than those without, and their role in refining clinical staging requires further investigation.

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.

Safety and efficacy of left colic artery preservation in laparoscopic anterior resection for lower rectal cancer

Background: To evaluate the safety and efficacy of left colic artery (LCA) preservation in laparoscopic anterior resection with D3 lymphadenectomy for lower rectal cancer. Methods: A total of 117 patients with lower rectal cancer who received laparoscopic anterior resection were retrospectively analyzed. Results: No differences were detected in terms of the numbers of harvested lymph nodes and metastatic lymph nodes, the intraoperative and postoperative complications or the postoperative recurrence and survival rates between the two groups (p > 0.05), but the LCA preservation group showed a lower anastomotic leakage rate than the LCA nonpreservation group (2/49 vs 12/68). Conclusion: LCA preservation may help reduce the incidence of anastomotic leakage without impairing surgical and oncological outcomes.

Verification of blood flow path reconstruction mechanism in distal sigmoid colon and rectal cancer after high IMA ligation through preoperative and postoperative comparison by manual subtraction CTA

INTRODUCTION

We aimed to investigate manual subtraction computed tomography angiography (MS-CTA) to further confirm the distribution and classification of LCA (left colic artery) ascending/descending branches, then observe the postoperative blood flow path to illustrate how the above branches evolved to postoperative blood path.

MATERIAL AND METHODS

89 patients with distal sigmoid and rectal cancer were referred in our observation and underwent MS-CTA between June 2020 and March 2022. We classified the distribution of LCA and confirmed whether there exists AMCA (accessory middle colic artery). Then we planned blood flow path based on the classification of LCA branches before operation. High ligation was applied in regular radical surgery. During operation, we carefully protect the bifurcation of ascending and descending LCA. Then we compared the planned blood flow path with the actual postoperative blood flow path to verify the mechanism we proposed previously.

RESULTS

Of 89 patients, 82 cases met our criteria, we summarized 6 distribution pattens of LCA ascending and descending branches. These preoperative pattens are consistent with the inspection during operation. The postoperative blood flow path of 6 pattens is evolved from the above adjacent anastomotic branches and is consistent with the planned blood flow path. We also found 2 cases with IMA stenosis and 1 case with SMA stenosis under pathological condition, and their compensatory blood flow path is in accordance with our theory. The rate of the anastomotic leakage in our study group is relatively low (7.3%).

CONCLUSION

MS-CTA could confirm the distribution of LCA and AMCA, display accurate postoperative blood reconstruction path after IMA high ligation, and it further verified the mechanism we proposed previously, which is the proximal anastomotic branches forming new blood flow path from high-pressure area to the low-pressure area. This mechanism might be helpful for performing accurate laparoscopic sigmoid and rectal cancer surgery.

Discontinuity of marginal artery at splenic flexure and rectosigmoid junction: A systematic review and meta-analysis

AIM

The aim of this study was to provide comprehensive evidence-based assessment of the discontinuity of the marginal artery at the splenic flexure (SF) and the rectosigmoid junction (RSJ).

METHOD

A systematic review was conducted of literature published to 26 December 2022 in the electronic databases PubMed, SCOPUS and Web of Science to identify studies eligible for inclusion. Data were extracted and pooled into a meta-analysis using the Metafor package in R. The primary outcomes were the pooled PPEs of the marginal artery at the SF and the RSJ. The secondary outcome was the size of vascular anastomoses.

RESULTS

A total of 21 studies (n = 2,864 patients) were included. The marginal artery was present at the splenic flexure in 82% (95% CI: 62-95) of patients. Approximately 81% (95% CI: 63-94%) of patients had a large macroscopic anastomosis, while the remainder (19%) had small bridging ramifications forming the vessel. The marginal artery was present at the RSJ in 82% (95% CI: 70-91%) of patients.

CONCLUSION

The marginal artery may be absent at the SF and the RSJ in up to 18% of individuals, which may confer a higher risk of ischaemic colitis. As a result of high interstudy heterogeneity noted in our analysis, further well-powered studies to clarify the prevalence of the marginal artery at the SF and the RSJ, as well as its relationship with other complementary colonic collaterals (intermediate and central mesenteric), are warranted.

Transanal drainage tube for the prevention of anastomotic leakage after rectal cancer surgery: a meta-analysis of randomized controlled trials

Background

Anastomotic leakage (AL) is a serious complication of anterior resection for rectal cancer. The use of transanal drainage tubes (TDT) during surgery to prevent AL remains controversial. Therefore, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to determine the efficacy of TDT in reducing AL.

Methods

Relevant data and studies published from inception until November 1, 2022, were retrieved from PubMed, Embase, and Cochrane Library databases to compare the incidence of AL after anterior resection for rectal cancer with and without TDT.

Results

This meta-analysis included 5 RCTs comprising 1385 patients. The results showed that the intraoperative use of TDT could not reduce the incidence of AL after rectal cancer surgery (risk ratio [RR], 0.91; 95% confidence interval [CI], 0.52-1.59; p = 0.75). A subgroup analysis of different degrees of AL revealed that TDT did not reduce the incidence of postoperative grade B AL (RR, 1.18; 95% CI, 0.67-2.09; p = 0.56) but decreased the incidence of grade C AL (RR, 0.28; 95% CI: 0.12-0.64; p = 0.003). Further, TDT did not reduce the incidence of AL in patients with rectal cancer and a stoma (RR, 2.40; 95% CI, 1.01-5.71; p = 0.05).

Conclusion

TDT were ineffective in reducing the overall incidence of AL, but they might be beneficial in reducing the incidence of grade C AL in patients who underwent anterior resection. However, additional multicenter RCTs with larger sample sizes based on unified control standards and TDT indications are warranted to validate these findings.

The SAGES MASTERS program presents: the top 10 seminal articles for laparoscopic left and sigmoid colectomy pathway for uncomplicated disease

BACKGROUND

As one of the 8 Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) Masters Program clinical pathways, the Colorectal Pathway aims to deliver educational content for the general surgeon organized along 3 levels of performance (competency, proficiency and mastery) each represented by an anchoring procedure. In this article, the SAGES Colorectal Task Force presents focused summaries of the top 10 seminal articles selected for laparoscopic left/sigmoid colectomy for uncomplicated disease.

METHODS

Using a systematic literature search of Web of Science, the most cited articles on laparoscopic left and sigmoid colectomy were identified, reviewed, and ranked by members of the SAGES Colorectal Task Force. Additional articles not identified in the literature search were included if deemed impactful by expert consensus. The top 10 ranked articles were then summarized, including their findings, strengths and limitations with emphasis on relevance and impact in the field.

RESULTS

The top 10 articles selected focus on variations in minimally invasive surgical techniques, video demonstrations, stratified approaches for benign and malignant disease as well as assessments of the learning curve.

CONCLUSIONS

The selected top 10 seminal articles for laparoscopic left and sigmoid colectomy in uncomplicated disease are considered by the SAGES colorectal task force to be fundamental to the knowledge base of minimally invasive surgeons as they progress to mastery in these procedures.

Laparoscopic D3 lymph node dissection with left colic artery and first sigmoid artery preservation in rectal cancer

BACKGROUND

D3 lymph node dissection with left colic artery (LCA) preservation in rectal cancer surgery seems to have little effect on reducing postoperative anastomotic leakage. So we first propose D3 lymph node dissection with LCA and first sigmoid artery (SA) preservation. This novel procedure deserves further study.

METHODS

Rectal cancer patients who underwent laparoscopic D3 lymph node dissection with LCA preservation or with LCA and first SA preservation between January 2017 and January 2020 were retrospectively assessed. The patients were categorized into two groups: the preservation of the LCA group and the preservation of the LCA and first SA group. A 1:1 propensity score-matched analysis was performed to decrease confounding.

RESULTS

Propensity score matching yielded 56 patients in each group from the eligible patients. The rate of postoperative anastomotic leakage in the preservation of the LCA and first SA group was significantly lower than that in the LCA preservation group (7.1% vs. 0%, P=0.040). No significant differences were observed in operation time, length of hospital stay, estimated blood loss, length of distal margin, lymph node retrieval, apical lymph node retrieval, and complications. A survival analysis showed patients' 3-year disease-free survival (DFS) rates of group 1 and group 2 were 81.8% and 83.5% (P=0.595), respectively.

CONCLUSION

D3 lymph node dissection with LCA and first SA preservation for rectal cancer may help reduce the incidence of anastomotic leakage without compromising oncological outcomes compare with D3 lymph node dissection with LCA preservation alone.

The SAGES MASTERS program presents: the top 10 seminal articles for laparoscopic left and sigmoid colectomy pathway for uncomplicated disease

BACKGROUND

As one of the 8 Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) Masters Program clinical pathways, the Colorectal Pathway aims to deliver educational content for the general surgeon organized along 3 levels of performance (competency, proficiency and mastery) each represented by an anchoring procedure. In this article, the SAGES Colorectal Task Force presents focused summaries of the top 10 seminal articles selected for laparoscopic left/sigmoid colectomy for uncomplicated disease.

METHODS

Using a systematic literature search of Web of Science, the most cited articles on laparoscopic left and sigmoid colectomy were identified, reviewed, and ranked by members of the SAGES Colorectal Task Force. Additional articles not identified in the literature search were included if deemed impactful by expert consensus. The top 10 ranked articles were then summarized, including their findings, strengths and limitations with emphasis on relevance and impact in the field.

RESULTS

The top 10 articles selected focus on variations in minimally invasive surgical techniques, video demonstrations, stratified approaches for benign and malignant disease as well as assessments of the learning curve.

CONCLUSIONS

The selected top 10 seminal articles for laparoscopic left and sigmoid colectomy in uncomplicated disease are considered by the SAGES colorectal task force to be fundamental to the knowledge base of minimally invasive surgeons as they progress to mastery in these procedures.

International survey among surgeons on the perioperative management of rectal cancer

BACKGROUND

Several pivotal studies and international guidelines on the perioperative management of rectal cancer have been published. However, little is known about the current state of perioperative management of rectal cancer patients in clinical practice worldwide.

METHODS

An online survey including 13 questions focusing on key topics related to the perioperative management of patients with rectal cancer was conducted among colorectal surgeons registered within the database of the Research Institute Against Digestive Cancer (IRCAD).

RESULTS

A total of 535 respondents from 89 countries participated in the survey. Most surgeons worked in the European region (40.9%). Two hundred and fifty-four respondents (47.5%) performed less than 25% of surgical procedures laparoscopically. The most commonly used definition of the upper limit of the rectum was a fixed distance from the anal verge (23.4%). Magnetic resonance imaging was used to define the upper limit of the rectum by 258 respondents (48.2%). During total mesorectal excision (TME), 301 respondents (56.3%) used a high-tie technique. The most commonly constructed anastomosis was an end-to-end anastomosis (68.2%) with the majority of surgeons performing a leak test intraoperatively (88.9%). A total of 355 respondents (66.4%) constructed a diverting ostomy, and the majority of these surgeons constructed an enterostomy (82%). A total of 208 respondents (39.3%) closed a stoma within 8 weeks. Lastly, 135 respondents (25.2%) introduced a solid diet on postoperative day 1.

CONCLUSION

There is considerable heterogeneity in the perioperative management of rectal cancer patients worldwide with several discrepancies between current international practice and recommendations from international guidelines. To achieve worldwide standardization in rectal cancer care, further research is needed to elucidate the cause of this heterogeneity and find ways of improved implementation of best practice recommendations.

5 year oncological outcomes of the HIGHLOW randomized clinical trial

INTRODUCTION

The oncological outcomes of low ligation (LL) compared to high ligation (HL) of the inferior mesenteric artery (IMA) during low-anterior rectal resection (LAR) with total mesorectal excision are still debated. The aim of this study is to report the 5 year oncologic outcomes of patients undergoing laparoscopic LAR with either HL vs. LL of the IMA MATERIALS AND METHODS: Between June 2014 and December 2016, patients who underwent elective laparoscopic LAR + TME in 6 Italian non-academic hospitals were randomized to HL or LL of IMA after meeting the inclusion criteria (HighLow trial; ClinicalTrials.gov Identifier NCT02153801). We analyzed the rate of local recurrence, distant metastasis, overall survival, disease-specific survival, and disease-free survival at 5 years of patients previously enrolled.

RESULTS

Five-year follow up data were available for 196 patients. Recurrence happened in 42 (21.4%) of patients. There was no statistically significant difference in the distant recurrence rate (15.8% HL vs. 18.9% LL; P = 0.970) and pelvic recurrence rate (4,9% HL vs 3,2% LL; P = 0.843). No statistically significant difference was found in 5-year OS (p = 0.545), DSS (p = 0.732) or DFS (p = 0.985) between HL and LL. Low vs medium and upper rectum site of tumor, conversion rate, Clavien-Dindo post-operative grade ≥3 complications and tumor stage were found statistically significantly associated to poor oncological outcomes in univariate analysis; in multivariate analysis, however, only conversion rate and stage 3 cancer were found to be independent risk factors for poor DFS at 5 years.

CONCLUSION

We confirmed the results found in the previous 3-year survival analysis, the level of inferior mesenteric artery ligation does not affect OS, DSS and DFS at 5-year follow-up.

Feasibility of preservation of superior rectal artery plus dissection of lymph nodes around inferior mesenteric artery in laparoscopic resection for sigmoid colon cancer

Background

Limited data are available about superior rectal artery (SRA) preservation in laparoscopic resection for sigmoid colon cancer (SCC). This study aimed to evaluate the short-term and long-term efficacies of SRA preservation in laparoscopic radical resection for SCC.

Methods

We retrospectively analyzed 207 patients with SCC who underwent laparoscopic radical resection for SCC from January 2017 to June 2021. A total of 84 patients received lymph node clearance around the inferior mesenteric artery (IMA) root (D3 lymph node dissection) with preservation of SRA (SRA preservation group), and 123 patients received high ligation of the IMA (control group). The clinicopathological data of the two groups were compared, and Kaplan-Meier method was performed to estimate patient survival.

Results

Compared with the control group, the operation time of the SRA preservation group was longer (p < 0.001), but the postoperative exhaust and defecation times were significantly shorter (p = 0.003, p < 0.001). Two cases of postoperative ileus and four cases of anastomotic leakage were observed in the control group, whereas the SRA preservation group had none. However, no statistical difference was observed between the groups (p = 0.652, p = 0.248). The overall survival also showed no significant difference in (p = 0.436).

Conclusion

Preservation of SRA plus dissection of lymph nodes around IMA did not increase postoperative morbidity and mortality nor affect the prognosis of patients but increased the bowel blood supply, which may have a significant positive effect on the recovery of postoperative intestinal function and reduction of anastomotic leakage.

Potential short-term outcome advantage of low vs. high ligation of inferior mesenteric artery for sigmoid and rectal cancer: propensity score matching analysis

BACKGROUND

Whether to ligate the inferior mesenteric artery at its root during anterior resection for sigmoid colon or rectal cancer is still under debate. This study compared the surgical outcomes, postoperative recovery, and anastomotic leakage between high and low ligation of the inferior mesenteric artery through a subgroup analysis.

METHODS

This was a retrospective analysis of prospectively collected data. All patients who underwent colorectal resection for rectosigmoid cancer between December 2016 and December 2019 were enrolled. According to the surgical ligation level of the inferior mesenteric artery, the patients were categorized into either the high or low ligation group. The investigated population was matched using the propensity score method.

RESULTS

Overall, 894 patients with sigmoid or rectal cancer underwent elective anterior resection with high (577 patients) or low (317 patients) ligation of the inferior mesenteric artery. After the propensity score matching, 245 patients in each group were compared. High ligation of the inferior mesenteric artery was associated with higher incidence of anastomotic leakage (14.9% vs. 5.6%, P = 0.041) for mid- to low-rectum tumors and a higher incidence of complications (8.6% vs. 3.3%, P = 0.013) of grades 1-2 according to the Clavien-Dindo classification system.

CONCLUSION

Compared with high ligation, low ligation of the inferior mesenteric artery resulted in lower likelihood of morbidity and mortality in rectal and sigmoid cancers. Moreover, low ligation was less likely to result in anastomosis leakage in mid- to low-rectal cancers.

High and low inferior mesenteric artery ligation in laparoscopic low anterior rectal resections: A retrospective study

Backgroud

The high or low inferior mesenteric artery (IMA) ligation in rectal cancer remains a great debate. This study retrospectively discussed the outcomes of the perioperative period, defecation and urinary function and long-term prognosis in rectal cancer patients with high or low IMA ligation.

Methods

This study enrolled 220 consecutive rectal cancer cases, including 134 with high IMA ligation and 86 with low ligation. A comparison between the two groups was made for anastomotic leakage, low anterior resection syndrome (LARS), international prostate symptom score (IPSS), 5-year disease-free survival (DFS) and 5-year overall survival (OS).

Results

Low-ligation group had a longer operative time, and larger intraoperative blood loss. No significant difference was noted in anastomotic leakage incidence. In multivariable analysis, the male gender and tumor located at the lower rectum were identified as risk factors for anastomotic leakage. No significant differences were observed between groups in their LARS and IPSS questionnaire responses. The high-ligation vs. the low-ligation 5-year OS and DFS were 78.3% vs. 82.4% and 72.4% vs. 76.6%, respectively, which were not statistically different.

Conclusion

The ligation level of the IMA had no significant effect on the anastomotic leakage incidence, defecation, urinary function, and long-term prognosis.

Short- and long-term outcomes of preservation versus ligation of the inferior mesenteric artery in laparoscopic D3 lymph node dissection for descending colon cancer: a propensity score-matched analysis

PURPOSE

This study aimed to compare the short- and long-term outcomes of laparoscopic D3 lymph node (LN) dissection between ligation of the inferior mesenteric artery (IMA) (LIMA) and preservation of the IMA (PIMA) for descending colon cancer using propensity score-matched analysis.

METHODS

This retrospective study included 101 patients with stage I-III descending colon cancer who underwent laparoscopic D3 LN dissection with LIMA (n = 60) or PIMA (n = 41) at a single center between January 2005 and March 2022. After propensity score matching, 64 patients (LIMA, n = 32; PIMA, n = 32) were included in the analysis. The primary endpoint was the long-term outcomes, and the secondary endpoint was the surgical outcomes.

RESULTS

In the matched cohort, no significant difference was noted in the surgical outcomes, including the operative time, estimated blood loss, number of harvested LNs, number of harvested LN 253, and complication rate. The long-term outcomes were also not significantly different between the LIMA and PIMA groups (3-year recurrence-free survival, 72.2% vs. 75.6%, P = 0.862; 5-year overall survival, 69.8% vs. 63.4%, P = 0.888; 5-year cancer-specific survival, 84.2% vs. 82.8%, P = 0.607). No recurrence of LN metastasis was observed around the IMA root.

CONCLUSION

Laparoscopic D3 dissection in PIMA was comparable to that in LIMA regarding both short- and long-term outcomes. The optimal LN dissection for descending colon cancer should be investigated in future large-scale studies.

Comparison of Postoperative Outcome and Prognosis Among Laparoscopic Left Colectomy and Laparoscopic Sigmoidectomy in Sigmoid Colon Cancer Patients: A Propensity Score Matching Study

PURPOSE

The purpose of this study was to investigate the effect of laparoscopic left colectomy (LLC) and laparoscopic sigmoidectomy (LSD) on short-term outcomes and prognosis of sigmoid colon cancer (SCC) patients using propensity score matching (PSM).

METHODS

In this retrospective study, the SCC patients who underwent LLC or LSD surgery were collected from a single clinical center from Jan 2011 to Dec 2019. Short-term outcomes and prognosis were compared between patients who received LSD surgery and LLC surgery.

RESULTS

A total of 356 patients were included in this study. After 1:1 PSM analysis, there were 50 patients who underwent LLC surgery and 50 patients who underwent LSD surgery left in this study. No significant difference was found in baseline characteristics after PSM (P > .05). In comparison with the LLC surgery group, the LSD surgery group had shorter operation time (P = .003) after PSM. Moreover, the surgical procedure was not an independent predictor for overall survival (OS) (P = .918, 95% CI = .333-2.688) and disease-free survival DFS (P = .730, 95% CI = .335-2.150), but age (OS: P = .009, 95% CI = 1.010-1.075; DFS: P = .014, 95% CI = 1.007-1.061) and tumor stage (OS: P = .004, 95% CI = 1.302-3.844; DFS: P < .01, 95% CI = 1.572-4.171) were the independent risk factors for OS and DFS in SCC patients.

CONCLUSION

There was no significant difference between the two surgical procedures for prognosis of SCC patients. However, the possible reasons for changing the surgical procedures should be cautious by surgeons.

[Primary retroperitoneal approach for vessel-sparing D3-lymph node dissection in left colonic and rectal cancer resections - the first Russian experience]

OBJECTIVE

To develop and describe a technique of primary retroperitoneal approach for vessel-sparing D3-lymph node dissection in the left colon and rectal cancer surgery; to evaluate the short-term results of the first series of patients treated with a new minimally invasive method.

MATERIAL AND METHODS

The first 10 patients with adenocarcinoma of the left colon and rectum, who underwent surgical treatment using the retroperitoneal approach with vessel-sparing D3 lymph node dissection, were included in the study. The primary retroperitoneal approach involved mobilization of the left side of the colon, D3 lymph node dissection with skeletonization of inferior mesenteric artery (IMA) and selective ligation of afferent vessels from retroperitoneal space using SILS access system at the first steps of surgery. Intersection of visceral and parietal peritoneum, as well as intersection of mesentery within the bowel resection borders was performed laparoscopically. Surgical specimen was removed through retroperitoneal access incision.

RESULTS

Duration of retroperitoneal stage with lymph node dissection was 100 min (70.0-115.0). There were 28.5 (22-37) regional lymph nodes removed during vessel-sparing D3 lymph node dissection with IMA skeletalization, 3 (1-4) metastatic regional lymph nodes and 3.5 (2-5) apical nodes. In 4 out of 10 patients, we damaged visceral peritoneum during retroperitoneal dissection. Two patients developed Clavien-Dindo grade 1-2 complications. Mean postoperative hospital stay was 8 days (5-12).

CONCLUSION

We developed retroperitoneal vessel-sparing D3 lymph node dissection for the treatment of left colon and rectal cancer. Initial results demonstrated safety and feasibility of this approach.

The Colorectal Anastomosis: A Timeless Challenge

Colorectal anastomosis is a sophisticated problem that demands an elaborate discussion and an elegant solution. "Those who forget the past are condemned to repeat it." George Santayana, Life of Reason , 1905.

Selective approach to arterial ligation in radical sigmoid colon cancer surgery with D3 lymph node dissection: A multicenter comparative study

Objectives

Radical surgery for sigmoid colon cancer is commonly performed with complete mesocolic excision (CME) and apical lymph node dissection, reached by central vascular ligation (CVL) of the inferior mesenteric artery (IMA) and associated extended left colon resection. However, IMA branches can be ligated selectively according to tumor location with D3 lymph node dissection (LND), economic segmental colon resection and tumorspecific mesocolon excision (TSME) if IMA is skeletonized. This study aimed to compare left hemicolectomy with CME and CVL and segmental colon resection with selective vascular ligation (SVL) and D3 LND.

Material and Methods

Patients (n= 217) treated with D3 LND for adenocarcinoma of the sigmoid colon between January 2013 and January 2020 were included in the study. The approach to vessel ligation, colon resection and mesocolon excision was based on tumor location in the study group, while in the comparison group, left hemicolectomy with routine CVL was performed. Survival rates were estimated as the primary endpoints of the study. Long- and short-term surgery-related outcomes were evaluated as the secondary endpoints of the study.

Results

The studied approach to the IMA branch ligation was associated with a statistically significant decrease in intraoperative complication rates (2 vs 4, p= 0.024), operative procedure length (225.56 ± 80.356 vs 330.69 ± 175.488, p <0.001), and severe postoperative morbidity (6.2% vs 19.1%, p= 0.017). Meanwhile, the number of examined lymph nodes significantly increased (35.67 vs 26.69 per specimen, p <0.001). There were no statistically significant differences in survival rates.

Conclusion

Selective IMA branch ligation and TSME resulted in better intraoperative and postoperative outcomes with no difference in survival rates.

Development and validation of artificial intelligence models for preoperative prediction of inferior mesenteric artery lymph nodes metastasis in left colon and rectal cancer

BACKGROUND

Dissection of lymph nodes at the roots of the inferior mesenteric artery (IMAN) should be offered only to selected patients at a major risk of developing IMAN involvement. The aim of this study is to present the first artificial intelligence (AI) models to predict IMAN metastasis risk in the left colon and rectal cancer patients.

METHODS

A total of 2891 patients with descending colon including splenic flexure, sigmoid colon and rectal cancer undergoing major primary surgery and IMAN dissection were included as a study cohort, which was then split into a training set (67%) and a testing set (33%). Feature selection was conducted using the least absolute shrinkage and selection operator (LASSO) regression model. Seven AI algorithms, namely Support Vector Machine (SVM), Logistic Regression (LR), Extreme Gradient Boosting (XGB), Light Gradient Boosting (LGB), Decision Tree Classifier (DTC), Random Forest (RF) classifier, and Multilayer Perceptron (MLP), as well as traditional multivariate LR model were employed to construct predictive models. The optimal hyperparameters were determined with 5 fold cross-validation. The predictive performance of models and the expert surgeon was assessed and compared in the testing set independently.

RESULTS

The IMAN involvement incidence was 4.6%. The optimal set of features selected by LASSO included 10 characteristics: neoadjuvant treatment, age, synchronous liver metastasis, synchronous lung metastasis, signet ring adenocarcinoma, neural invasion, lymphovascular invasion, CA199, endoscopic obstruction, T stage evaluated by MRI. The most accurate model derived from MLP showed excellent prediction power with area under the receiver operating characteristic curve (AUROC) of 0.873 and produced 81.0% recognition sensitivity and 82.5% specificity in the testing set independently. In contrast, the judgment of IMAN metastasis by expert surgeon yield rather imprecise and unreliable results with a significantly lower AUROC of 0.509. Additionally, the proposed MLP had the highest net benefits and the largest reduction of unnecessary IMAN dissection without the cost of additional involved IMAN missed.

CONCLUSION

MLP model was able to maintain its prediction accuracy in the testing set better than other models and expert surgeons. Our MLP model could be used to help identify IMA nodal metastasis and to select candidates for individual IMAN dissection.

D3 lymph node dissection with versus without left colic artery preservation in single-incision laparoscopic surgery for sigmoid and rectosigmoid cancer: A propensity score-matched analysis

PURPOSE

In surgery for colorectal cancer, dissection of the lymph nodes and fatty tissue around the root of the inferior mesenteric artery is important from an oncologic point of view. However, it is debatable whether it is better to preserve or remove the left colic artery (LCA). This study aimed to compare D3 lymphadenectomy with versus without LCA preservation in single-incision laparoscopic surgery for sigmoid and rectosigmoid cancer.

METHODS

A total of 1138 patients underwent surgery for colorectal cancer between April 2011 and December 2018 at Fukui Prefectural Hospital. This propensity score-matched retrospective study analyzed the data of 163 patients: 42 patients with LCA preservation (group A) and 129 without LCA preservation (group B). Clinical and oncological outcomes were compared between the two groups.

RESULTS

There were no significant differences between groups A and B in patient characteristics, surgical outcomes, including the 5-year overall survival rate (75% vs. 64.2%, hazard ratio [HR] 1.34, 95% confidence interval [CI] 0.37-4.30), 5-year disease-free survival rate (85.7% vs. 85.7%, HR 0.99, 95% CI 0.24-4.22), and 5-year cancer-specific survival rate (92.8% vs. 89.3%, HR 1.50, 95% CI 0.25-11.4).

CONCLUSION

There were no significant differences in the short- and long-term outcomes of patients who underwent single-incision laparoscopic surgery with D3 lymphadenectomy with versus without LCA preservation. This suggests that LCA preservation is safe and feasible in single-incision laparoscopic surgery for sigmoid and rectosigmoid colon cancer.

Comparing the short-term results of the improved triangular anastomosis technique for complete laparoscopic radical resection of sigmoid colon cancer and laparoscopic-assisted small incision colon reconstruction: A CONSORT study

The laparoscopic approaches using the triangular anastomosis technique for sigmoid colon cancer (SCC) are rare. This CONSORT study explored the short-term effects of laparoscopic radical resection of SCC with modified triangular anastomosis technique and laparoscopic-assisted small incision colon cancer reconstruction surgery. From April 2019 to January 2021, a total of 86 patients with SCC who were admitted to Luopu County People's Hospital were selected and received radical resection. Patients were divided into 2 groups using a random number table method: in the control group, patients underwent laparoscopic-assisted small-incision reconstruction surgery, and patients in the observation group underwent complete laparoscopic surgery with modified triangular anastomosis technique. The 2 groups were compared in perioperative related indicators and postoperative complications. After 3 months follow-up, local tumor recurrence and metastasis, abdominal wall puncture and implantation, and death were observed. Compared to the control group, shorter operation time, gastrointestinal reconstruction time, postoperative exhaust time, hospitalization time, and less intraoperative blood loss, and lower probability of complications were observed in the observation group (P < .05). However, there was no significant difference in the number of lymph node dissections between the 2 groups (P > .05). After 3 months of follow-up, no local tumor recurrence, distant tumor metastasis, abdominal wall puncture implantation, and death were found in the 2 groups of patients. It is indicated that the improved triangular anastomosis technique for complete laparoscopic radical resection of SCC is effective in treatment for SCC.

The significance of anatomical variation of the inferior mesenteric artery and its branches for laparoscopic radical resection of colorectal cancer: a review

Currently, high or low ligation of the inferior mesenteric artery (IMA) is a controversial issue in laparoscopic radical surgery for colorectal cancer. High or low ligation of the IMA has both advantages and disadvantages, and the level of ligation during the left colon and/or rectum resection has been a dilemma for surgeons. One important factor influencing the surgeon's decision to ligate the IMA in a high or low position is the anatomical type of the IMA and its branches. Some studies confirm that the anatomy of the IMA and its branches is critical to the anastomotic blood supply and, therefore, influences the choice of surgical approach (level of ligation of the IMA). However, many vascular variations in the anatomy of the IMA and its branches exist. Herein, we have summarized the anatomical types of the IMA and its branches, finding that the classification proposed by Yada et al. in 1997 is presently accepted by most scholars. Based on Yada's classification, we further summarized the characteristics of the IMA's various anatomical types as a guide for high or low ligation in radical colorectal cancer surgery.

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.

Analysis of Risk Factors for Anastomotic Leakage After Laparoscopic Anterior Resection of Rectal Cancer and Construction of a Nomogram Prediction Model

Objective

To explore the risk factors of anastomotic leakage (AL) after laparoscopic anterior resection (AR) of rectal cancer and establish a nomogram prediction model.

Methods

Clinical and surgical data of patients who underwent AR of rectal cancer at Sichuan Cancer Hospital from January 2017 to December 2020 were retrospectively collected. Univariate and multivariate logistic regression analyses were used to screen the independent risk factors of AL after AR. A nomogram risk prediction model was established based on the selected independent risk factors and the predictive performance of nomogram was evaluated.

Results

A 1013 patients undergoing laparoscopic AR were included, of which 67 had AL, with an incidence of 6.6%. Univariate and multivariate logistic regression analyses showed that male gender, tumors distance from the anus verge of ≤ 5cm, tumors distance from the anus verge of 5–10cm, circumferential tumor growth, operation time ≥ 240min, and no diverting stoma were independent risk factors for AL after AR. A nomogram prediction model was established based on these results. The calibration curve showed that the predicted occurrence probability of the nomogram model was in good agreement with the actual occurrence probability. The area under the receiver operating characteristic (ROC) curve was 0.749.

Conclusion

The nomogram prediction model based on the independent risk factors of patients undergoing AL after AR can effectively predict the probability of AL.

Usefulness of Computed Tomography Angiography in the Preoperative Workup of Patients With Colorectal Cancer

OBJECTIVES

The objective of this study is to analyze the main patterns of branching of the inferior mesenteric artery (IMA) and to determine if your knowledge changes the surgical strategy in the colorectal cancer.

METHODS

This retrospective study included 63 patients with cancer of the sigmoid or rectum. We assessed the patterns of IMA in 3 subtypes: type A (independent left colic artery [LCA]), type B (LCA and sigmoid artery arising in a common trunk) and type C (LCA, sigmoid artery, and superior rectal artery with a common origin). Colorectal surgeons evaluated how the vascular map changed the type of IMA ligation.

RESULTS

Inferior mesenteric artery branching was classified as type A in 55.6% patients, type B in 23.8%, and type C in 20.6%. Knowledge of the vascular map changed the type of ligation from high to low in 20 of the 50 patients who were candidates for surgery. The change was possible in tumors located in the sigmoid colon and the rectosigmoid junction with the type A or B branching.

CONCLUSIONS

Preoperative Multidetector Computed Tomography angiography can define the pattern of IMA branching. Based on this information, a low ligation can be performed in tumors located in sigmoid colon and rectosigmoid junction with IMA branching types A and B.

Three-dimensional versus conventional two-dimensional laparoscopic colectomy for colon cancer: A 3-year follow-up study

Background

Three-dimensional (3D) laparoscopy was developed to overcome the drawbacks of two-dimensional (2D) laparoscopy, namely lack of depth perception. However, the benefit of 3D laparoscopy in colorectal surgery is inconclusive. Here, we compare the 3-year follow-up outcomes of 3D and 2D laparoscopic colectomy.

Patients and Methods

A total of 91 consecutive patients who underwent either 3D or 2D laparoscopy colectomy from October 2015 to November 2017 by a single surgical team for colon cancer were enrolled. Data were collected from a prospectively constructed database, including clinico-pathological features and operative parameters. The pathological results, recurrence, survival and systemic treatment were collected from the Taiwan Cancer Database.

Results

There were 47 patients in the 3D group and 44 in the 2D group. There were no significant differences in characteristics of patients, operation data, pathological results, complications, operative time, blood loss or the number of lymph node harvested between the two groups. In addition, disease-free survival and overall survival were equal between the two groups.

Conclusions

This is the first long-term result of a 3D laparoscopic colectomy. In our 3-year follow-up, there was no difference in long-term outcomes between 2D and 3D laparoscopy for colorectal surgery in an experienced centre.

Patent data access control and protection using blockchain technology

The purposes are to develop the patent data profoundly, control the data access process effectively, and protect the patent information and content. The traditional patent review systems are analyzed. For the present patent data security and privacy protection technologies and algorithms, the patent information data are stored on different block nodes after data fragmentation using blockchain technology. Then the data are shared using the data encryption algorism. In this way, data access control can be restricted to particular users. Finally, a patent data protection scheme based on privacy protection is proposed. The security of the scheme and the model performance are verified through simulation experiments. The time required to encrypt 10 MB files with 64-bit and 128-bit data is 35 ms and 105 ms, respectively. The proposed re-encryption algorithm only needs 1 s to decrypt 64 KB data, and only 1% of the data needs asymmetric encryption. This greatly reduces the computational overhead of encryption. Results demonstrate that the system can effectively control the access methods of users, efficiently protect the personal privacy and patent content of patent applicants, and reduce the patent office cloud computing overhead using the local resources of branches. The distributed storage methods can reduce the cloud system interaction of the patent office, thereby greatly improving the speed of encryption and ensuring data security. Compared with the state of the art methods, the proposed patent data access and protection system based on blockchain technology have greater advantages in data security and model performance. The research results can provide a research foundation and practical value for the protection and review systems of patent data.

Extended Versus Standard Complete Mesocolon Excision in Sigmoid Colon Cancer: A Multicenter Randomized Controlled Trial

OBJECTIVE

The aim of this study was to evaluate whether extended complete mesocolic excision (e-CME) for sigmoid colon cancer improves oncological outcomes without compromising morbidity or functional results.

BACKGROUND

In surgery for cancer of the sigmoid colon and upper rectum, s-CME removes the lymphofatty tissue surrounding the inferior mesenteric artery (IMA), but not the lymphofatty tissue surrounding the portion of the inferior mesenteric vein that does not run parallel to the IMA. Evidence about the safety and efficacy of extending CME to include this tissue is lacking.

METHODS

This single-blind study randomized sigmoid cancer patients at 4 centers to undergo e-CME or s-CME. The primary outcome was the total number of lymph nodes harvested. Secondary outcomes included disease-free and overall survival at 2 years, morbidity, and bowel and genitourinary function. Clinicaltrials.gov: NCT03107650.

RESULTS

We analyzed 93 patients (46 e-CME and 47 s-CME). Perioperative outcomes were similar between groups. No differences between groups were found in the total number of lymph nodes harvested [21 (interquartile range, IQR, 14-29) in e-CME vs 20 (IQR, 15-27) in s-CME, P = 0.873], morbidity (P = 0.829), disease-free survival (P = 0.926), or overall survival (P = 0.564). The extended specimen yielded a median of 1 lymph node (range, 0-6), none of which were positive.Bowel function recovery was similar between arms at all timepoints. Males undergoing e-CME had worse recovery of urinary function (P = 0.026).

CONCLUSION

Extending lymphadenectomy to include the IMV territory did not increase the number of lymph nodes or improve local recurrence or survival rates.

Surgeon's role in CT-based preoperative determination of inferior mesenteric artery anatomy in colorectal cancer treatment

BACKGROUND

The inferior mesenteric artery (IMA) is a blood vessel of great importance in left colon and rectal cancer surgery. We aimed to determine the role of surgeons in computed tomography (CT) based vascular anatomy interpretation.

METHOD

Patients with left colon and rectal cancer treated surgically with D3 lymph node dissection and selective vascular ligation were included in this study. All patients (n=250) underwent preoperative CT with intravenous contrast. The IMA anatomy was schematically depicted by surgeon based on CT interpretation. Intraoperatively anatomy was defined by skeletonisation of the IMA. All patients had segmental resection with selective vascular ligation. The concurrence of prospectively obtained results were evaluated by intraclass correlation and Kendall's tau-b test. Misinterpretation of IMA anatomy was analysed by CT-specialist.

RESULTS

The preoperative and intraoperative IMA anatomy features were correctly interpreted in 237 cases (in 94.8%) within skeletonisation extent, which is supported by high level of agreement and concordance of preoperative data regards to intraoperative findings (K=0.926; p<0.001; CC=0.912; p<0.001). As a result of the CT-based evaluation of the IMA, E, K, and H types of branching patterns were proposed. IMV position was mistakenly identified in 2.6% of cases.

CONCLUSION

Surgeons are able to evaluate the IMA anatomy accurately with CT and use it in routine preoperative planning. The E, K, and H branching types may be used when defining approach to skeletonisation and level of vascular ligation.

High Ligation of the Inferior Mesenteric Artery Induces Hypoperfusion of the Sigmoid Colon Stump During Anterior Resection

Background: Anastomotic leakage (AL) after colorectal surgery is associated with insufficient vascular perfusion of the anastomotic ends. This study aimed to evaluate the effect of high vs. low ligation of the ileocolic artery and inferior mesenteric artery, respectively, on the vascular perfusion of the bowel stumps during ileocecal resection (ICR) and anterior rectal resection (AR). Methods: We retrospectively evaluated patients who underwent ICR or AR between 2016 and 2020. Real-time indocyanine green fluorescence angiography was performed to measure the fluorescence time (FT) as a marker of the blood flow in the proximal and distal stumps before anastomosis. Results: Thirty-four patients with lower right-sided colon cancer underwent laparoscopic ICR. Forty-one patients with rectosigmoid colon or rectal cancer underwent robotic high AR (HAR) (n = 8), robotic low AR (LAR) (n = 6), laparoscopic HAR (n = 8), or laparoscopic LAR (n = 19). The FT was similar in the ileal and ascending colon stumps (p = 1.000) and did not differ significantly between high vs. low ligation of the ileocolic artery (p = 0.934). The FT was similar in the sigmoid colon and rectal stumps (p = 0.642), but high inferior mesenteric artery ligation significantly prolonged FT in the sigmoid colon during AR compared with low ligation (p = 0.004), indicating that the high ligation approach caused significant hypoperfusion compared with low ligation. The AL rate was similar after low vs. high ligation. Conclusions: Low vascular perfusion of the bowel stumps may not be an absolute risk factor for AL. High inferior mesenteric artery ligation could induce sigmoid colon stump hypoperfusion during anterior rectal resection.

Low Ligation Plus High Dissection Versus High Ligation of the Inferior Mesenteric Artery in Sigmoid Colon and Rectal Cancer Surgery: A Meta-Analysis

Background

Whether high or low ligation of the inferior mesenteric artery (IMA) is superior in surgery for rectal and sigmoid colon cancers remains controversial. Although several meta-analyses have been conducted, the level of lymph node clearance was poorly defined. We performed a meta-analysis comparing high and low ligation of the IMA for sigmoid colon and rectal cancers, with emphasis on high dissection of the lymph node at the IMA root in all the included studies.

Methods

PubMed, MEDLINE, and EMBASE databases were searched to identify relevant articles published until 2020. The patient’s perioperative and oncologic outcomes were analyzed. Statistical analysis was performed using the statistical software RevMan version 5.4.

Results

A total of 17 studies, including four randomized controlled trials, published between 2011 and 2020 were selected. In total, 1,846 patients received low ligation of the IMA plus high dissection of lymph nodes (LL+HD), and 2,648 patients received high ligation of the IMA (HL). LL+HD was associated with low incidence of anastomotic leakage (p < 0.001), borderline long operative time (p = 0.06), and less yields of total lymph nodes (p = 0.03) but equivalent IMA root lymph nodes (p = 0.07); moreover, LL+HD exhibited non-inferior long-term oncological outcomes.

Conclusion

In comparison with HL, LL+HD was an effective and safe oncological procedure for sigmoid colon and rectal cancers. Therefore, to ligate the IMA below the level of the left colic artery with D3 high dissection for sigmoid colon and rectal cancers might be suggested once the surgeons are familiar with this technique.

Systematic Review Registration

INPLASY.com, identifier 202190029.

The efficacy of ileostomy after laparoscopic rectal cancer surgery: a meta-analysis

Background

Protective ileostomy is always applied to avoid clinically significant anastomotic leakage and other postoperative complications for patients receiving laparoscopic rectal cancer surgery. However, whether it is necessary to perform the ileostomy is still controversial. This meta-analysis aims to analyze the efficacy of ileostomy on laparoscopic rectal cancer surgery.

Methods

Cochrane Library, EMBASE, Web of Science, and PubMed were applied for systematic search of all relevant literature, updated to May 07, 2021. Studies compared patients with and without ileostomy for laparoscopic rectal cancer surgery. We applied Review Manager software to perform this meta-analysis. The quality of the non-randomized controlled trials was assessed using the Newcastle-Ottawa scale (NOS), and the randomized studies were assessed using the Jadad scale.

Results

We collected a total of 1203 references, and seven studies were included using the research methods. The clinically significant anastomotic leakage rate was significantly lower in ileostomy group (27/567, 4.76%) than that in non-ileostomy group (54/525, 10.29%) (RR = 0.47, 95% CI 0.30–0.73, P for overall effect = 0.0009, P for heterogeneity = 0.18, I² = 32%). However, the postoperative hospital stay, reoperation, wound infection, and operation time showed no significant difference between the ileostomy and non-ileostomy groups.

Conclusion

The results demonstrated that protective ileostomy could decrease the clinically significant anastomotic leakage rate for patients undergoing laparoscopic rectal cancer surgery. However, ileostomy has no effect on postoperative hospital stay, reoperation, wound infection, and operation time. The efficacy of ileostomy after laparoscopic rectal cancer surgery: a meta-analysis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02432-x.