Predicting the pathological features of the mesorectum before the laparoscopic approach to rectal cancer

Predictive model of the surgical difficulty of robot-assisted total mesorectal excision for rectal cancer: a multicenter, retrospective study

Rectal cancer robotic surgery is becoming more and more common, but evidence for predicting surgical difficulty is scarce. Our goal was to look at the elements that influence the complexity of robot-assisted total mesorectal excision (R-TME) in the medical care of middle and low rectal cancer as well as to establish and validate a predictive model on the basis of these factors. Within this multicenter retrospective investigation, 166 consecutive patients receiving R-TME between January 2021 and December 2022 with middle and low rectal cancer were included and categorized according to the median operation time. A nomogram was created to forecast the procedure's complexity after variables that could affect its difficulty were found using logistic regression analysis. Using R software, a total of 166 patients were randomly split into two groups: a test group (48 patients) and a training group (118 patients) at a ratio of 7 to 3. The median operation time of all patients was 207.5 min; patients whose operation time was ≥ 207.5 min were allocated to the difficult surgery group (83 patients), and patients whose operation time was < 207.5 min were allocated to the nondifficult surgery group. Multivariate analysis revealed that body mass index (BMI), the gap between the tumor and the anal verge and the posterior rectal mesenteric thickness were independent predictors of surgical duration. A clinical predictive model was created and assessed employing the above independent predictors. The results of the receiver operating characteristic (ROC) analysis revealed the adequate discriminative ability of the predictive model. Our study revealed that it is feasible to predict surgical difficulty by obtaining clinical and magnetic resonance parameters for imaging (the gap between the anal verge and the tumour, and posterior mesorectal thickness), and these predictions could be useful in making clinical decisions.

Predictors of operative difficulty in robotic low anterior resection for rectal cancer

AIM

This study evaluates the relationship of tumour and anatomical features with operative difficulty in robotic low anterior resection performed by four experienced surgeons in a high-volume colorectal cancer practice.

METHODS

Data from 382 patients who underwent robotic low anterior resection by four expert surgeons between January 2016 and June 2019 were included in the analysis. Operating time was used as a measure of operative difficulty. Univariate and multivariate mixed models were used to identify associations between baseline characteristics and operating time, with surgeon as a random effect, thereby controlling for variability in surgeon speed and proficiency. In an exploratory analysis, operative difficulty was defined as conversion to laparotomy, a positive margin or an incomplete mesorectum.

RESULTS

Median operating time was 4.28 h (range 1.95-11.33 h) but varied by surgeon from 3.45 h (1.95-6.10 h) to 5.93 h (3.33-11.33 h) (P < 0.001). Predictors of longer operating time in multivariate analysis were male sex, higher body mass index, neoadjuvant radiotherapy, low tumour height, greater sacral height and larger mesorectal area at the S5 vertebral level. Conversion occurred in two cases (0.5%), and incomplete mesorectum and positive margins were found in nine (2.4%) and 19 (5.0%) patients, respectively. Neoadjuvant radiotherapy and larger pelvic outlet were the only characteristics associated with the exploratory measure of difficulty.

CONCLUSION

Predicting operative difficulty based on easy to identify, preoperative radiological and clinical variables is feasible in robotic anterior resection.

Standardization of ileoanal J-pouch surgery technique: Quality assessment of minimally invasive ileoanal J-pouch surgery videos

BACKGROUND

Ileal pouch anal anastomosis is a complex procedure associated with significant morbidity, with several complications after ileal pouch anal anastomosis surgery leading to pouch failure. The aim of the study is to evaluate the heterogeneity surrounding the technique of ileoanal J-pouch surgery by assessing the safety and quality of published online peer-reviewed surgical videos.

METHODS

Ileal pouch anal anastomosis videos published on peer-reviewed surgical journals and video channels were edited and anonymized to demonstrate specific steps of the surgical procedure: mobilization and division of the rectum, formation of the ileoanal J-pouch reservoir, anastomosis, and lengthening techniques. The anonymized videos were presented to a group of reviewers with expertise in ileal pouch anal anastomosis blinded to the names and affiliations of the surgeons performing the procedure. Primary outcome was the rate of interobserver variability in the assessment of specific technical steps of the ileal pouch anal anastomosis surgery procedure. Secondary outcome was the appropriateness of the use of surgical videos review as an assessment tool for ileal pouch anal anastomosis surgery, measured as rate of reviewers being unable to answer for poor video quality.

RESULTS

In total, 29 video fragments were distributed, and 13 assessors completed a 60-item survey, organized in 7 major domains. The survey completion rate was 93.4%. Out of a total 729 answers, in 23 (3.2%) the reviewers indicated they were unable to comment due to poor video image, and in 48 (6.5%) were unable to comment due to the particular step not being shown in the procedure. The proportion of assessors rating rectal mobilization technically appropriate ranged from 30.7% to 92.3% and from 7.7% to 69.2% for safety. The level of rectal division was considered appropriate in 0 to 53.8% of the videos, whereas the stapling technique used for rectal division was appropriate in 0 to 70% of the videos.

CONCLUSION

Our study assessed published peer-reviewed videos on ileal pouch anal anastomosis surgery and reported heterogeneity in the safety of the demonstrated techniques. Blind assessment of published peer-reviewed ileal pouch anal anastomosis videos reported a high rate of unsafe or inappropriate technique for rectal mobilization and transection in the reviewed videos, with fair interobserver agreement among reviewers. There is a need for consensus on what is considered safe and appropriate in ileal pouch anal anastomosis surgery. Peer review of ileal pouch anal anastomosis surgery videos could facilitate training and accreditation in this complex procedure.

Patient-specific mental rehearsal with three-dimensional models before low anterior resection: randomized clinical trial

Background

It was hypothesized that preparing for a surgical procedure, taking into account individual patient characteristics, may facilitate the procedure and improve surgical quality. The aim of this study was to compare different case-specific, preoperative mental rehearsal methods before minimally invasive rectal cancer surgery.

Methods

In this RCT, patients were allocated in a 1 : 1 : 1 : 1 ratio to four groups: systematic mental rehearsal (SMR) using MRI scans; SMR and three-dimensional (3D) virtual models; SMR and synthetic 3D printed models; and routine practice (control group). Surgeons operating on all but the control group underwent mental rehearsal with the visual aids, including axial MRI scans of the pelvis, interactive 3D virtual models reconstructed from axial MRIs, and synthetic models, manufactured by 3D printing. Operations were video-recorded and assessed by two experts blinded to allocation using two validated scores, the Competency Assessment Tool (CAT) and Objective Clinical Human Reliability Analysis (OCHRA). The primary outcome of the study was surgical performance, measured by the CAT.

Results

Forty-nine patients were randomized and allocated to the four groups. There were 12 participants in each of the control, MRI and SMR, and virtual and SMR groups, whereas the SMR using physical models and simulation group included 13. No difference was observed between groups in median CAT scores (control 30.50, MRI 34.25, virtual 31.75, physical 34.00; P = 0.748, partial η² <0.001, where _pη² is indicative of effect size) or OCHRA scores (anterior, posterior, right and left lateral planes, transection P>0.200, _pη² =0.052–0.088). Time spent not performing dissection was significantly shorter for the SMR with MRI group than for the control (57.5 versus 42 respectively; P < 0.001, _pη² =0.212).

Conclusion

Mental rehearsal did not affect CAT and OCHRA scores of consultant surgeons. Reference number: ISRCTN 75603704 (https://www.isrctn.com).

Pelvic dimensions on preoperative imaging can identify poor-quality resections after laparoscopic low anterior resection for mid- and low rectal cancer

BACKGROUND

High-quality surgery is essential for optimal oncologic outcomes in rectal cancer, but total mesorectal excision (TME) can be difficult for mid- and low rectal cancers. Preoperative identification of patients at risk for difficult TME may change the operative approach. The objective of this study was to determine if MRI pelvimetry can predict poor-quality surgery in patients undergoing laparoscopic low anterior resection (LAR) for mid- and low rectal cancer.

METHODS

All patients undergoing laparoscopic LAR for rectal cancer ≤ 9 cm from the anal verge at a single tertiary care referral center from 2011 to 2017 were retrospectively reviewed. Pelvic dimensions were measured from preoperative staging MRI on sagittal and axial views. Pelvimetry variables were all dichotomized based on median values. Exploratory factor analysis then identified the most relevant variables for regression analysis. The primary outcome was poor-quality resection, defined as an incomplete mesorectal grade, or involved circumferential (CRM) or distal (DRM) resection margins.

RESULTS

There were 92 patients included in this study, of which 70% were male, the mean BMI was 26.0 kg/m², and the mean tumor height was 6.6 cm. Preoperative (chemo)radiotherapy was administered in 70%, and the pathologic T-stage was T3/T4 in 41%. The overall incidence of poor-quality resection was 17%, including 13% incomplete TME, 7% involved CRM, and 1% involved DRM. Factor analysis identified S1-pubic symphysis and the angle between S1 and S5-bottom of symphysis (angle ABD) as relevant variables. After adjusting for pathologic T-stage, BMI, and tumor height, a S1-S5-bottom of symphysis angle > 74.3^° (OR 6.19, 95% CI 1.18-32.37) independently predicted poor-quality resection.

CONCLUSIONS

MRI pelvimetry can identify patients at risk for a poor-quality resection after laparoscopic proctectomy for mid- and low rectal cancer. These patients may benefit from the selective use of more advanced access methods to improve surgical resection quality.

Prediction of surgical difficulty in minimally invasive surgery for rectal cancer by use of MRI pelvimetry

Background

Technical difficulties in rectal surgery are often related to dissection in a limited surgical field. This study investigated the clinical value of MRI pelvimetry in the prediction of surgical difficulty associated with minimally invasive rectal surgery.

Methods

Patients with rectal cancer who underwent laparoscopic or robotic total mesorectal excision between 2005 and 2017 were reviewed retrospectively and categorized according to surgical difficulty on the basis of duration of surgery, conversion to an open procedure, use of the transanal approach, postoperative hospital stay, blood loss and postoperative complications. Preoperative clinical and MRI‐related parameters were examined to develop a prediction model to estimate the extent of surgical difficulty, and to compare anastomotic leakage rates in the low‐ and high‐grade surgical difficulty groups. Prognosis was investigated by calculating overall and relapse‐free survival, and cumulative local and distant recurrence rates.

Results

Of 121 patients analysed, 104 (86·0 per cent) were categorized into the low‐grade group and 17 (14·0 per cent) into the high‐grade group. Multivariable analysis indicated that high‐grade surgical difficulty was associated with a BMI above 25 kg/m² (odds ratio (OR) 4·45, P = 0·033), tumour size 45 mm or more (OR 5·42, P = 0·042), anorectal angle 123° or more (OR 5·98, P = 0·028) and pelvic outlet less than 82·7 mm (OR 6·62, P = 0·048). All of these features were used to devise a four‐variable scoring model to predict surgical difficulty. In patients categorized as high grade for surgical difficulty, the anastomotic leakage rate was 53 per cent (9 of 17 patients), compared with 9·6 per cent (10 of 104) in the low‐grade group (P < 0·001). The high‐grade group had a significantly higher local recurrence rate than the low‐grade group (P = 0·002).

Conclusion

This study highlights the impact of clinical variables and MRI pelvimetry in the prediction of surgical difficulty in minimally invasive rectal surgery.

Predicting the level of difficulty of the double-stapling technique in laparoscopic total mesorectal excision

BACKGROUND

The transection of rectum and fashioning of anastomosis is a crucial step in laparoscopic total mesorectal excision (TME) and the double-stapling technique (DST) is often employed. This study aimed to evaluate the factors that were associated with difficult DST.

METHOD

Cases of laparoscopic TME were retrospectively reviewed. The clinico-anatomical parameters were retrieved from a prospectively maintained database. In addition, pelvic dimensions were taken by reviewing the magnetic resonance imaging scan. The number of stapler cartridges used for intracorporeal transection of rectum was used as a surrogate for the level of difficulty of DST and its relationship with various parameters were evaluated.

RESULTS

There were a total of 121 consecutive cases analyzed. The mean number of stapler cartridges used was 2.1 ± 0.7. Pelvic inlet (p = 0.002) and tumor height (p = 0.015) were predictors of the number of cartridges used, R² = 0.366. A model was developed to predict the likelihood of transecting the rectum with two or less stapler cartridges, which included the following parameters: gender, pelvic inlet, interspinous distance, intertuberous distance, and tumor height. The predicted probability also correlated with overall operation time (p = 0.009) and anastomotic leakage (p = 0.023).

CONCLUSION

The difficulty of DST was associated with patient's clinico-anatomical factors. Surgeons can consider other feasible alternatives, like transanal anastomosis, when a technically challenging DST is anticipated.

Anatomical basis for the choice of laparoscopic surgery for low rectal cancer through the pelvic imaging data-a cohort study

Background

Low rectal cancer surgery without anus conservation needs permanent ileostomy or colostomy which seriously affects the quality of life of patients. Therefore, low rectal cancer surgery not only pays attention to the safety of surgical treatment but also to the anus conservation.

Methods

Sixty-seven patients suffering from low rectal cancer had undergone laparoscopic surgery which was analyzed through retrospective study. They were divided into the anus-conserving and non-anus-conserving groups. Thirty-five set of pelvic data was obtained from the preoperative CT and MRI images. After that, the discriminant function was obtained to predict the surgery methods for patients with low rectal carcinoma.

Results

Anal-conserving group discriminant function (F1) = − 33.698 + 6.045 × anal margin distance (cm) + 1.105 × T4; non-anus-conserving group discriminant function (F2) = − 14.125 + 3.138 × anal margin distance (cm) + 0.804 × T4. If F1 is greater than F2, then the case can be treated as the anus reservation while if F2 is greater than F1 the case cannot be treated anus reservation. The accuracy of the discriminant function was evaluated which was found to be 97%.

Conclusion

The discriminant function of pelvic data provides anatomical basis for the choice of surgical methods for low rectal cancer.

Predictors of surgical outcomes and survival in rectal cancer patients undergoing laparoscopic total mesorectal excision after neoadjuvant chemoradiation therapy: the interest of pelvimetry and restaging magnetic resonance imaging studies

BACKGROUND

Locally advanced rectal cancer (LARC) requires a multimodal therapy tailored to the patient and tumor characteristics. Pretreatment magnetic resonance imaging (MRI) is necessary to stage the primary tumor, while restaging MRI, which is not systematically performed, may be of interest to identify poor responders to neoadjuvant chemoradiation therapy (NCRT), and redefine therapeutic approach. The EuMaRCS study group aimed to investigate the role and accuracy of pretreatment (including pelvimetry) and restaging MRIs in predicting surgical difficulties and surgical outcomes in LARC therapy.

METHODS

Patients with mid or low LARC who were administered NCRT, who underwent laparoscopic total mesorectal excision, and for whom pretreatment and restaging MRIs were available, were included.

RESULTS

MRIs of 170 patients (median age: 61 years) were reanalyzed by the same radiologist. Pelvimetry differed significantly between males and females, but no gender difference was noted in the clinical and tumor characteristics. Tumor volume and tumor height assessed on the restaging MRI were associated, respectively, with operative time and estimated blood loss. Conversion was predicted by tumor volume, interischial distance and pubic tubercle height. The quality of the surgical resection was found to be a predictor of overall and disease-free survival. The sensitivity and specificity of tumor regression grade 1 to identify a pathologic complete response were 76.9% and 89.3%, respectively.

CONCLUSIONS

In LARC management, pelvimetry and restaging MRI may be useful to predict surgical difficulties and surgical outcomes. However, the main independent predictor of patient survival appears to be the achievement of a successful surgical resection.

Present status and perspectives of endosonography 2017 in gastroenterology

Endoscopic ultrasound has become an essential tool in modern gastroenterology and abdominal surgery. Compared with all other endoscopic methods, it has the most potential for innovation and its future looks bright. Thus, we compiled this summary of established and novel applications of endoscopic ultrasound methods to inform the reader about what is already possible and where future developments will lead in improving patient care further. This review is structured in four parts. The first section reports on developments in diagnostic endoscopic ultrasound, the second looks at semi-invasive endoscopic ultrasound, and the third discusses advances in therapeutic endoscopic ultrasound. An overview on the future prospects of endoscopic ultrasound methods concludes this article.

Mental practice with interactive 3D visual aids enhances surgical performance

BACKGROUND

Evidence suggests that Mental Practice (MP) could be used to finesse surgical skills. However, MP is cognitively demanding and may be dependent on the ability of individuals to produce mental images. In this study, we hypothesised that the provision of interactive 3D visual aids during MP could facilitate surgical skill performance.

METHODS

20 surgical trainees were case-matched to one of three different preparation methods prior to performing a simulated Laparoscopic Cholecystectomy (LC). Two intervention groups underwent a 25-minute MP session; one with interactive 3D visual aids depicting the relevant surgical anatomy (3D-MP group, n = 5) and one without (MP-Only, n = 5). A control group (n = 10) watched a didactic video of a real LC. Scores relating to technical performance and safety were recorded by a surgical simulator.

RESULTS

The Control group took longer to complete the procedure relative to the 3D&MP condition (p = .002). The number of movements was also statistically different across groups (p = .001), with the 3D&MP group making fewer movements relative to controls (p = .001). Likewise, the control group moved further in comparison to the 3D&MP condition and the MP-Only condition (p = .004). No reliable differences were observed for safety metrics.

CONCLUSION

These data provide evidence for the potential value of MP in improving performance. Furthermore, they suggest that 3D interactive visual aids during MP could potentially enhance performance, beyond the benefits of MP alone. These findings pave the way for future RCTs on surgical preparation and performance.

Current concepts of colorectal cancer resection pathology

The discussion of pathology results is one of the important items in the multidisciplinary meeting. These results describe not only the adequacy of earlier treatments (neoadjuvant therapy, surgery), but guide subsequent treatment decisions by providing staging information and additional prognostic and predictive factors. In the era of next-generation sequencing, every so often the emphasis is put on the molecular background of tumours, but the information that can be retrieved from the resection specimen remains essential for optimal patient care. In the current review the different surgical approaches will be described, together with the relevant macroscopic evaluations. Microscopic features will be addressed, giving an overview that is aimed at optimal information exchange in the multidisciplinary meeting. Finally, special requirements for reporting local excisions and specimen after neoadjuvant therapy will be discussed.