Short-term outcomes of robotic tumor-specific mesorectal resection of rectal cancer: surgical techniques in mesorectal division using rolling division of the mesorectum.

BACKGROUND: This study aims to report our surgical techniques for robot-assisted laparoscopic anterior resection, specifically focusing on mesorectal division using rolling division of the mesorectum, and to elucidate short-term outcomes at a single institution. Tumor-specific mesorectal excision (TSME) is commonly performed for resection of a tumor located in the upper rectum. However, especially in a narrow pelvis, it is difficult to perform appropriate mesorectal division at an adequate distance from the tumor in robot-assisted laparoscopic anterior resection. METHODS: Retrospective case series of patients with rectal cancer who underwent robot-assisted TSME using rolling division of mesorectum. Patient characteristics, perioperative clinical results, surgical and pathological details were recorded. RESULTS: A total of 198 patients underwent robot-assisted TSME for rectal cancer using rolling division of mesorectum between May 2019 and December 2023.The tumor was located in the upper rectum in 45 patients, middle rectum in 115 patients and lower rectum in 38 patients. The types of resections were 40 high anterior resection and 158 low anterior resections. The median operation time was 175 (range 109-310) min, and median mesorectal division time was 24 (range 15-45) min. Median blood loss was 3 (range 0-20) ml; no patients required blood transfusion. The overall complication rate of Clavien-Dindo classification grades I-IV was 7.1%. Anastomotic leakage was observed in two patients (1.0%) with grade III. There was no surgical mortality in this series. CONCLUSION: This robotic technique for anterior resection is a feasible and reliable procedure for achieving sufficient and safe TSME in this cohort.

Supine bottom-up extralevator abdominoperineal excision for anorectal adenocarcinoma is not inferior to standard approach and may be thus safely performed.

BACKGROUND: Extralevator abdominoperineal excision (APE) for rectal carcinoma has been described in order to improve pathological and oncological results compared to standard APE. To obtain the same oncological advantages as extralevator APE, we have previously described a new procedure starting by a perineal approach: the supine bottom-up APE. Our objective is to compare oncological and surgical outcomes between the supine bottom-up APE and the standard APE. METHODS: All patients with low rectal adenocarcinoma requiring APE were retrospectively included and divided into 2 groups: supine bottom-up APE (Group A) and standard APE (Group B). RESULTS: From 2008 to 2016, 61 patients were divided into Groups A (n = 30) and B (n = 31). Postoperative outcomes and median length of stay were similar between groups. Patients from Group A had a significantly longer distal margin (30 [8-120] vs. 20 [1.5-60] mm, p = 0.04) and higher number of harvested lymph nodes (14.5 [0-33] vs. 11 [5-25], p = 0.03) than those from Group B. Circumferential resection margin involvement was similar between groups (28 vs. 22%, p = 0.6), whereas tumors from Group A were significantly larger and more frequently classified as T4 than those from Group B. Operative time was significantly shorter in Group A (437.5 [285-655] minutes) than in Group B (537.5 [361-721] minutes, p = 0.0009). At the end of follow-up, local recurrence occurred in 7 and 16% of patients from Groups A and B (p = 0.68). Three-year overall and disease-free survival rates were similar between groups (87 vs. 90%, p = 0.62 and 61 vs. 63%, p = 0.88, respectively). CONCLUSION: Our findings suggest that supine bottom-up APE doesn't impair surgical outcomes, pathological results, overall and disease-free survivals in comparison with standard APE. This new procedure may be thus safely performed and decrease the operative time. Further randomized multicentric studies are required to confirm these results.

Predictors for selective flexure mobilization during robotic anterior resection for rectal cancer: a prospective cohort analysis.

INTRODUCTION: Splenic flexure mobilization (SFM) may be indicated during anterior resection to provide a tension-free anastomosis. However, to date, no score allows identifying patients who may benefit from SFM. METHODS: Patients who underwent robotic anterior resection for rectal cancer were identified from a prospective register. Demographic and cancer-related variables were extracted, and predictors of SFM were identified using regression models. Thereafter, 20 patients with SFM and 20 patients without SFM were randomly selected and their pre-operative CTscan were reviewed. The radiological index was defined as 1/(sigmoid length/pelvis depth). The optimal cut-off value for predicting SFM was identified using ROC curve analysis. RESULTS: Five hundred and twenty-four patients were included. SFM was performed in 121 patients (27.8%) and increased operative time by 21.8 min (95% CI: 11.3 to 32.4, p < 0.001). The incidence of postoperative complications did not differ between patient with or without SFM. Realization of an anastomosis was the main predictor for SFM (OR: 42.4, 95% CI: 5.8 to 308.5, p < 0.001). In patients with colorectal anastomosis, both sigmoid length (15 ± 5.1 cm versus 24.2 ± 80.9 cm, p < 0.001) and radiological index (1 ± 0.3 versus 0.6 ± 0.2, p < 0.001) differed between patients who had SFM and patients who did not. ROC curve analysis of the radiological index indicated an optimal cut-off value of 0.8 (sensitivity: 75%, specificity: 90%). CONCLUSION: SFM was performed in 27.8% of patients who underwent robotic anterior resection, and increased operative time by 21.8 min. For optimal surgical planning, patients requiring SFM can be identified based on pre-operative CT using the index 1/(sigmoid length/pelvis depth) with a cut-off value set at 0.8.

Efficacy of transperineal minimally invasive surgery with laparoscopic abdominoperineal excision for lower rectal cancer.

PURPOSE: In abdominoperineal excision (APE), the advantages of the "down-to-up" approach are expected to be more obvious when performed as a two-team approach, including transperineal minimally invasive surgery (TpMIS). We investigated the efficacy of TpMIS with laparoscopic APE for lower rectal cancer. METHODS: Patients who underwent laparoscopic APE with (n = 20) or without (n = 30) TpMIS between December 2013 and April 2020 were retrospectively reviewed. Patient and tumor characteristics, intraoperative outcome, short-term outcome, and pathological findings were compared. Additional subgroup analyses were performed in technically challenging cases, including male patients, obese patients, and patients with tumors located at the anterior wall. RESULTS: There was no marked difference in the patient or tumor characteristics or short-term outcomes, including morbidity and mortality between the two groups. Pathological results were comparable, and the circumferential resection margin (CRM) positive rate was 10% in both groups. TpMIS achieved a significant reduction in operative time (p = 0.02). In a subgroup analysis, the amount of blood loss was also smaller in males (p = 0.02) and patients with a high BMI (> 25) (p = 0.005) than in others. CONCLUSION: Simultaneously performing TpMIS and laparoscopic APE is feasible owing to the favorable complication and CRM-positive rates. In terms of operative time and blood loss, TpMIS is expected to be advantageous in both easy and challenging cases.

Long-term outcomes after close rectal dissection and total mesorectal excision in ileal pouch-anal anastomosis for ulcerative colitis.

BACKGROUND: During ileal pouch-anal anastomosis (IPAA) surgery for ulcerative colitis (UC), rectal dissection can be performed via close rectal dissection (CRD) or in a total mesorectal excision plane (TME). Although CRD should protect autonomic nerve function, this technique may be more challenging than TME. The aim of this study was to compare long-term outcomes of patients undergoing CRD and TME. METHODS: This single-centre retrospective cohort study included consecutive patients who underwent IPAA surgery for UC between January 2002 and October 2017. Primary outcomes were chronic pouch failure (PF) among patients who underwent CRD and TME and the association between CRD and developing chronic PF. Chronic PF was defined as a pouch-related complication occurring ≥ 3 months after primary IPAA surgery requiring redo pouch surgery, pouch excision or permanent defunctioning ileostomy. Secondary outcomes were risk factors and causes for chronic PF. Pouch function and quality of life were assessed via the Pouch dysfunction score and Cleveland global quality of life score. RESULTS: Out of 289 patients (155 males, median age 37 years [interquartile range 26.5-45.5 years]), 128 underwent CRD. There was a shorter median postoperative follow-up for CRD patients than for TME patients (3.7 vs 10.9 years, p < 0.01). Chronic PF occurred in 6 (4.7%) CRD patients and 20 (12.4%) TME patients. The failure-free pouch survival rate 3 years after IPAA surgery was comparable among CRD and TME patients (96.1% vs. 93.5%, p = 0.5). CRD was a no predictor for developing chronic PF on univariate analyses (HR 0.7 CI-95 0.3-2.0, p = 0.54). A lower proportion of CRD patients developed chronic PF due to a septic cause (1% vs 6%, p = 0.03). CONCLUSIONS: Although differences in chronic PF among CRD and TME patients were not observed, a trend toward TME patients developing chronic pelvic sepsis was detected. Surgeons may consider performing CRD during IPAA surgery for UC.

Quantitative assessment of the microstructure of the mesorectum with different prognostic statuses by intravoxel incoherent motion diffusion-weighed magnetic resonance imaging.

BACKGROUND: The mesorectum surrounding the rectum provides an ideal substrate for tumour spread. However, preoperative risk assessment is still an issue. This study aimed to investigate the microstructural features of mesorectum with different prognostic statuses by intravoxel incoherent motion diffusion-weighted imaging (IVIM DWI). METHODS: Patients with pathologically proven rectal adenocarcinoma underwent routine high-resolution rectal magnetic resonance imaging (MRI) and IVIM DWI sequences were acquired. The MRI-detected circumferential resection margin (mrCRM) and extramural vascular invasion (mrEMVI) were evaluated. IVIM parameters of the mesorectum adjacent to (MAT) and distant from (MDT) the tumour were measured and compared between and within the prognostic factor groups. RESULTS: The positive mrCRM (pMAT < 0.001; pMDT = 0.013) and mrEMVI (pMAT = 0.001; pMDT < 0.001) groups demonstrated higher D values in the MAT and MDT than the corresponding negative groups. Conversely, the positive mrCRM (p = 0.001) and mrEMVI (p < 0.001) groups both demonstrated lower f values in the MAT. Similarly, in the self-comparison between the MAT and MDT in the above subgroups, D showed a significant difference in all subgroups (p < 0.001 for all), and f showed a significant difference in the positive mrCRM (p = 0.001) and mrEMVI (p = 0.002) groups. Moreover, the MAT displayed a higher D* in the positive mrCRM (p = 0.014), negative mrCRM (p = 0.009) and negative mrEMVI groups (p < 0.001). CONCLUSION: The microstructure of the mesorectum in patients with rectal cancer with poor prognostic status shows changes based on IVIM parameters. IVIM parameters might be promising imaging biomarkers for risk assessment of tumour spread in mesorectum preoperatively.

Cavernous hemangioma of the mesorectum involving the rectum: a rare case report.

BACKGROUND: Gastrointestinal hemangiomas are very rare and are even rarer in the mesorectum. It is not clear whether mesorectal hemangiomas originate in the bowel wall or in the mesorectum. For clinicians, to correctly identify the imaging features of mesorectal hemangiomas is important. CASE PRESENTATION: We herein describe a case of a 31-year-old male that presented with hematochezia and sensation of rectal tenesmus. Both the rectal MRI and contrast-enhanced CT scan of the whole abdomen indicated rectal wall thickening, marked dilatation, and tortuous vessels around the rectum. In addition, a contrast-enhanced portal venous phase CT scan showed the dilation of portal vein, splenic vein and inferior mesenteric vein. The dilated inferior mesenteric vein extending down to the mesorectum, and became marked dilatation and tortuous vessels around the rectum. The patient underwent laparoscopic surgical resection of the mesorectal lesion and the involved portions of the rectum. The surgical samples underwent pathological analysis, and a diagnosis of cavernous hemangioma was confirmed. Seven days after surgery, the patient was discharged without postoperative complications. CONCLUSIONS: This case highlights the imaging features of mesorectal hemangiomas. In addition, in this current case, the mesorectal hemangioma more likely originated in the mesorectum.

Analysis of presacral tissue structure in LARS and the prevention of LARS by reconstruction of presacral mesorectum with pedicled greater omentum flap graft.

BACKGROUND: The greater omentum has played a unique biological role in regenerative surgery. The aim of our study was to alter the anterior sacral structure by filling the anterior sacral space with the greater omentum and evaluate its effect on the low anterior resection syndrome (LARS) after total mesorectal excision (TME) surgery for low rectal cancer. METHODS: We retrospectively collected clinical data of patients with primary low rectal cancer who underwent TME and ileostomy closure in our hospital from March 2018 to March 2020. Spearman correlation analysis was conducted to analyze the correlation between postoperative mesorectal fascia (MRF) thickness and LARS score. Subsequently, we prospectively used a tipped greater omental flap graft to reconstruct the anterior rectal sacral structures (MRF reconstruction) in 17 patients and compared LARS scores and rectal compliance (RC) at week 12 after closure of the ileostomy in both groups. RESULTS: There were 47 patients with No-MRF reconstruction (31 males, mean age 60.68 ± 9.21 years) and 17 with MRF reconstruction (10 males, mean age 49.82 ± 14.74 years). Correlation analysis indicated that MRF thickness and RC were negatively correlated with LARS severity (p < 0.05). The LARS score of patients with MRF reconstruction at 12 weeks was significantly better than that of those with No-MRF reconstruction (32.97 ± 2.65 vs. 26.94 ± 1.52, p = 0.001), and the RC of MRF reconstruction were lower (2.80 ± 0.55 vs. 3.67 ± 0.38, p = 0.001). In addition, MRF reconstruction and No-MRF reconstruction have the similar incidence of postoperative complications (p = 0.156). No hemorrhage or necrosis of the greater omentum flap was observed in any of the patients. CONCLUSIONS: Greater omentum flap transplantation can significantly improve the symptoms of LARS at 12 weeks after ileostomy closure and we expect it to become a new surgical procedure for the treatment of low rectal cancer.

Evaluation of Mesorectal Microcirculation With Quantitative Dynamic Contrast-Enhanced MRI.

OBJECTIVE. The purpose of this study was to use quantitative dynamic contrast-enhanced MRI (DCE-MRI) to evaluate mesorectal microcirculation in patients with rectal cancer. MATERIALS AND METHODS. A total of 53 patients with semicircular rectal tumors underwent DCE-MRI with a 3-T MRI system before surgery. ROIs were manually delineated in the mesorectum that surrounded the tumor and the mesorectum that surrounded the normal rectal wall. DCE-MRI parameters including forward volume transfer constant (Ktrans), reverse volume transfer constant (kep), and fractional extravascular extracellular space volume (Ve) were estimated using computer software. Histopathologic analysis served as the standard reference. RESULTS. Mesorectum that surrounded the tumor showed significantly higher Ktrans val ues than mesorectum that surrounded normal rectal wall (mean, 0.069 ± 0.035 [SD] vs 0.039 ± 0.020 min-1; p < 0.001). The tumor-surrounding mesorectum also showed higher Ve values than normal mesorectum (p < 0.001). An opposite trend was observed for kep, but this was not significant (p = 0.077). A lower Ktrans of the tumor-surrounding mesorectum was observed in patients with malignant lymph nodes compared with those with benign lymph nodes (mean, 0.054 ± 0.027 vs 0.076 ± 0.036 min-1; p = 0.034). Although kep values for the tumor-surrounding mesorectum were higher in patients with tumors categorized as pathologic Tis (pTis) to pT2 than in those with pT3 tumors, the p value was close to 0.05 (p = 0.047). The tumor-surrounding mesorectum showed no significant differences in the aforementioned parameters between patients with positive MRI-detected extramural vascular invasion (mrEMVI) and those with negative mrEMVI. CONCLUSION. Mesorectum that surrounded rectal tumor had a higher blood flow than that close to the normal rectal wall. The blood flow decreased in the tumor-surrounding mesorectum when there was nodal involvement.

Relationship between anastomotic leakage and CT value of the mesorectum in laparoscopic anterior resection for rectal cancer.

OBJECTIVE: This study aims to indicate whether the CT value of the mesorectum could be correlated with the incidence of anastomotic leakage (AL) in laparoscopic surgery for rectal cancer. METHODS: The study subjects included 173 patients who underwent laparoscopic anterior resection (LAR) for rectal cancer from September 2005 to 2016 in our institution as well as reliable contrast-enhanced CT preoperatively. Univariate and multivariate analyses were performed to determine the correlation between surgical outcomes, including AL and CT value of the mesorectum. RESULTS: AL was observed in 30 (17.3%) patients. Amongst short-term surgical outcomes, overall complication showed significant correlation with the CT value of the mesorectum (P = 0.003). In addition, AL was the only factor, which significantly correlated with the CT value of the mesorectum (P = 0.017). By plotting receiver operating characteristic curve, -75 HU was the threshold of the CT value of the mesorectum for predicting AL with an area under the curve of 0.772. Categorized into two groups as per the threshold, low group showed significantly higher incidence of AL (OR, 2.738; 95% CI, 1.105-6.788; P = 0.030) as well as whole complications (OR, 4.431; 95%CI, 1.912-10.266; P = 0.001). CONCLUSION: The CT value of the mesorectum may be a helpful preoperative radiological biomarker to predict AL after LAR for rectal cancer.

Completeness of total mesorectum excision of laparoscopic versus robotic surgery: a review with a meta-analysis.

BACKGROUND: TME has revolutionized the surgical management of rectal cancer, and since the introduction of robotic TME (RTME), many reports have shown the feasibility and the safety of this approach. However, concerns persist regarding the advantages of robotic in surgery for the completeness of TME. The aim of this review is to compare robotic versus laparoscopic total mesorectal excision (TME) in rectal cancer, focusing on the completeness of TME. METHODS: A systematic search was performed in the electronic databases for all available studies comparing RTME versus conventional laparoscopic LTME with declared grade of mesorectum excision. Data regarding sample size, clinical and demographic characteristics, number of complete, nearly complete, and incomplete TME were extracted. Primary outcome was the number of complete TME in robotic and laparoscopic procedures. Secondary outcomes were the numbers of nearly complete and incomplete TME in robotic and laparoscopic rectal resections. RESULTS: Twelve articles were included in the final analysis. Complete TME was reported by all authors, involving 1510 procedures, showing a significant difference in favor of robotic surgery (OR = 1.83, 95% CI 1.08-3.10, p = 0.03). Nearly complete and incomplete TME showed no significant difference between the procedures. Meta-regression analysis showed that none of patients' and tumors' characteristics significantly impacted on complete TME. CONCLUSIONS: Our results underline that the robotic approach to rectal resection is the better way to obtain a complete TME. However, it is mandatory that randomized clinical trials should be performed to assess definitively if robotic minimally invasive surgery is better than a laparoscopic resection.

The relationship between mesorectal grading and oncological outcome in rectal adenocarcinoma.

AIM: The prognostic association between mesorectal grading and oncological outcome in patients undergoing resection for rectal adenocarcinoma is controversial. The aim of this retrospective chart review was to determine the individual impact of mesorectal grading on rectal cancer outcomes. METHOD: We compared oncological outcomes in patients with complete, near-complete and incomplete mesorectum who underwent rectal excision with curative intent from 2009 to 2014 for Stage cI-III rectal adenocarcinoma. We also assessed the independent association of mesorectal grading and oncological outcome using multivariate models including other relevant variables. RESULTS: Out of 505 patients (339 men, median age of 60 years), 347 (69%) underwent a restorative procedure. There were 452 (89.5%), 33 (6.5%) and 20 (4%) patients with a complete, near-complete and incomplete mesorectum, respectively. Local recurrence was seen in 2.4% (n = 12) patients after a mean follow-up of 3.1 ± 1.7 years. Unadjusted 3-year Kaplan-Meier analysis by mesorectal grade showed decreased rates of overall, disease-free and cancer-specific survival and increased rates of overall and distant recurrence with a near-complete mesorectum, while local recurrence was increased in cases of an incomplete mesorectum (all P < 0.05). On multivariate analyses, a near-complete mesorectum was independently associated with decreased cancer-specific survival (hazard ratio 0.26, 95% CI 0.1-0.7; P = 0.007). There were no associations between mesorectal grading and overall survival, disease-free survival, overall recurrence or distant recurrence (all P > 0.05). CONCLUSION: Mesorectal grading is independently associated with oncological outcome. It provides unique information for optimizing surgical quality in rectal cancer.

[New perspectives in rectal cancer surgery: Transanal total mesorectal excision. Initial experiences]. / Új távlatok a végbélrák sebészetében: Transanalis teljes mesorectum excisio. Kezdeti eredményeink.

INTRODUCTION: Colorectal cancer is the second most frequent cause of oncologic mortality. Its key prognostic factors are operability and surgical quality. Total mesorectal excision is the gold standard of rectal cancer surgery, however, it is hardly achievable with the laparoscopic technique in a number of cases due to anatomical issues. Transanal total mesorectal excision (TaTME) is a new operative concept, which may address this technical problem. AIM: We aimed to present the initial Hungarian experiences with the new technique. METHOD: Retrospective analysis of clinical data of the first year case series at two Hungarian centers initiating the technique. RESULTS: A total of 17 transanal total mesorectal excision (TaTME) operations were performed at two centers. Major perioperative complications happened in two cases. There was no 30-day mortality. CONCLUSIONS: Early Hungarian experiences with transanal total mesorectal excision (TaTME) give hope of a brand new era of rectal cancer surgery. Orv Hetil. 2018; 159(1): 16-22.

Introduction to Total Mesorectal Excision.

Colorectal cancer is the second leading cause of mortality in the West, and rectal cancer accounts for about 25% of the colon cancers. The concept of total mesothelial excision (TME) was the most important event in surgery for rectal cancer of the last two decades, because even without a curative approach, it reduced local recurrence and extended 5-year survival.

Transanal NOTES total mesorectal excision (TME) in patients with rectal cancer: Is anatomy better preserved?

BACKGROUND: Natural orifice transluminal endoscopic surgery (NOTES) and single-incision laparoscopy are spreading worldwide. Total mesorectal excision (TME), the standard treatment for patients with distal rectal tumors, is usually performed in an "up-to-down" approach, either laparoscopically (LAPTME) or as an open procedure. We have already reported a NOTES-inspired, transanal, "down-to-up" variant of TME (NOTESTME). The main aim of this study was to assess the quality of the resected specimen in patients who had undergone either NOTESTME or LAPTME. METHODS: All patients with distal rectal neoplasia presenting between January 2011 and December 2014 were considered for the study. Additional inclusion criteria comprised American Society of Anesthesiologists score ≤ III and the absence of previous open surgery. Assignment to either group was sequential and based on the rank of inclusion in the study. The primary endpoint was the macroscopic quality of the specimen. Secondary endpoints included nerve visualization, tumor perforation, operating time, status of margins, and number of retrieved nodes. RESULTS: Eighteen patients (6 men, 12 women) were in the NOTESTME group and 15 (7 men, 8 women) in the LAPTME group, respectively. The TME specimen was considered complete or mainly regular in 16 patients who had undergone NOTESTME (88.9 %) and in 11 patients who had undergone LAPTME (73.3 %), (p > 0.05). During the procedure, we visually identified the neurovascular bundles of Walsh in 14 patients in the NOTESTME group (77.8 %) and in only 5 patients in the LAPTME group (33.3 %), (p < 0.05). Mean operative time was 245 min (range 155-440 min) in the NOTESTME group and 275 min (range 180-400 min) in the LAPTME group (p > 0.05). A median of 11 nodes per specimen (range 8-22 nodes) was retrieved in the NOTESTME group and 12 nodes (range 6-41 nodes) in the LAPTME group, respectively (p > 0.05). Distal and radial margins were comparable in both groups. CONCLUSIONS: Compared to the LAPTME, the NOTESTME seems to be associated with a more frequent intraoperative identification of the sacral nerves. However, the difference in overall quality of the retrieved specimen, although favoring NOTESTME, did not reach statistical significance in this small series.

Transanal total mesorectal excision: technical aspects of approaching the mesorectal plane from below.

Standardization of transanal total mesorectal excision requires the delineation of the principal procedural components before implementation in practice. This technique is a bottom-up approach to a proctectomy with the goal of a complete mesorectal excision for optimal outcomes of oncologic treatment. A detailed stepwise description of the approach with technical pearls is provided to optimize one's understanding of this technique and contribute to reducing the inherent risk of beginning a new procedure. Surgeons should be trained according to standardized pathways including online preparation, observational or hands-on courses as well as the potential for proctorship of early cases experiences. Furthermore, technological pearls with access to the "video-in-photo" (VIP) function, allow surgeons to link some of the images in this article to operative demonstrations of certain aspects of this technique.

Mesorectal pathologic assessment in two grades predicts accurately recurrence, positive circumferential margin, and correlates with survival.

BACKGROUND AND OBJECTIVES: We aimed to determine the prognostic value of the mesorectum quality assessed in a two-grade system compared with a classic system. METHODS: Consecutive patients undergoing surgery for rectal cancer were included (n = 103). Mesorectum was assessed into three grades (classic system: complete, nearly complete, incomplete) and compared with a two-grade system (adequate, inadequate). RESULTS: Mesorectum was complete in 62 (60.25%) patients, nearly complete in 21, and incomplete in 20. Reassessment showed adequate mesorectum in 83 (80.5%) patients and inadequate in 20. A R0 resection was achieved in 90.4% of adequate mesorectum and in 65% of inadequate mesorectum (P = 0.006). Recurrence was present in 18% of adequate mesorectum patients as compared with 50% of inadequate mesorectum (P = 0.003). The classic system failed to accurately predict the 5-year survival rate between complete (78.9%) and nearly complete (86.2%) categories (P = 0.235); whereas a two grading system showed a 5-year survival rate of 80.8% for adequate versus 39.3% for inadequate (P = 0.034). CONCLUSION: High recurrence occurred in inadecuate mesorectum patients and was correlated with R1/R2 resections, positive margins, and decreased survival. We propose a simplified classification of mesorectum that correlates with survival and overall recurrence.

Radiotherapy-induced mesorectum alterations: histological evaluation of 90 consecutive cases.

OBJECTIVE: In order to identify the radiotherapy-induced histological modifications in the mesorectum, we reviewed the surgical specimens of 90 rectal resections comprehensive of the total mesorectal excision (23 cases radiologically classified as cT2N0M0 and 67 as cT3N0M0). All patients were preoperative treated with radiotherapy: 20 with 50 Gy, 20 with 20 Gy and 50 Gy irradiation associated to FOLFOX scheme chemotherapy. MATERIAL AND METHODS: Routine hematoxylin and eosin stained serial slides at 5 mm of intervals were obtained from surgical specimens and included the tumor site and the adjacent irradiated mucosa, the submucosa and the muscular layers of the rectal wall and the mesorectal adipose tissue, completely removed until to the mesorectal fascia. Ten subjects (eight cT2N0M0 and two cT3N0M0), who did not received preoperative oncological treatments were adopted as controls. RESULTS: Histologically, examination revealed fibrosis of the adipose tissue in 86 cases (95%), vascular damage including vasculities and fibrotic thickening wall of arteries and veins in 46 cases (51%), sclero-hyalinosis of lymph nodes with pericapsular fibrosis in 22 cases (23%) and perineural deposition of fibrosis in 12 (13%). These findings were ubiquitously observed in the whole mesorectum. Fibrosis of the adipose tissue and vasculitis were mainly associated to the combination of 50 Gy radiations plus chemotherapy (p < 0.05). CONCLUSION: The detection of histopathological alterations in the mesorectum can give reason of the well-known postoperative complications and long-term sequels.

Anatomical considerations for transanal minimal-invasive surgery: the caudal to cephalic approach.

AIM: Nerve-sparing surgery during laparoscopic rectal mobilization is still limited by anatomical constraints such as obesity, the narrowness of the male pelvis, an ultra low rectal cancer or all of these. The transanal approach for total mesorectal excision has overcome the shortcomings of limited access to the rectal 'no-man's land' close to the pelvic floor. The aim of this anatomical study was to define a roadmap of anatomical landmarks for the caudal to cephalic approach so as to standardize nerve-sparing rectal mobilization procedures. METHOD: Macroscopic dissections of the pelvis in a caudal to cephalic direction were performed in eight alcohol-glycerol embalmed cadavers. A roadmap of anatomical landmarks was created at different levels of section to demonstrate the sites of nerve injury. RESULTS: Extrinsic autonomic nerves to the urogenital organs and the internal sphincter muscle are closely adjacent to the lowest portion of the rectum above the pelvic diaphragm. CONCLUSION: This anatomical guide for the pelvic surgeon should facilitate a safe and nerve-sparing dissection of the mesorectal plane with a meticulous overview of the lowest autonomic nerve fibres. New anatomical insights by a 'caudal to cephalic' approach to the 'no-man's land' should help overcome anatomical constraints of a narrow, obese and male pelvis during rectal mobilization procedures.