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

Navigating Complexity in Liver Resection: A Narrative Review of Factors Influencing Intraoperative Difficulty

Background: Liver resection remains the cornerstone for curative management in primary liver malignancies. Liver surgery ranges from simple wedge resections to complex hepatectomies involving vascular or biliary reconstructions. The anatomical complexity of the liver and these varied surgical approaches create challenges in assessing operative difficulty. This literature review explores the key factors influencing operative difficulty in liver resection for primary liver malignancy across surgical techniques. Methods: A broad literature review was conducted to determine the factors that were associated with increased operative difficulty in liver resection using the Embase, PubMed, and Cochrane databases for studies published between 2000 and 2025. Results: This review identifies several patient, tumor, and surgical factors that influence operative difficulty in liver resection. Numerous difficult scoring systems were identified, yet their applicability across different operative approaches remains uncertain. Across open and minimally invasive techniques, tumor size and location are commonly used to determine complexity. However, debate remains regarding the optimal cutoff for tumor diameter. Other identified factors include the extent of resection, patient-specific variables (e.g., cirrhosis, body mass index, previous surgeries), and surgical technique. In addition, liver resection procedures classified based on the 2000 Brisbane terminology have been stratified into three groups of increasing difficulty. Conclusion: The ability to predict operative difficulty is useful for case selection, surgical planning, and risk stratification for meaningful shared decision-making. Future research should focus on refining predictive models by integrating composite measures, including patient-reported outcomes and long-term survival. A unified, validated scoring system applicable across surgical techniques could enhance consistency in clinical practice and research to improve outcomes.

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.

Simple pelvimetry predicts the pelvic manipulation time in robot-assisted low and ultra-low anterior resection for rectal cancer

PURPOSE

This study explored the difficulty factors in robot-assisted low and ultra-low anterior resection, focusing on simple measurements of the pelvic anatomy.

METHODS

This was a retrospective analysis of the clinical data of 61 patients who underwent robot-assisted low and ultra-low anterior resection for rectal cancer between October 2018 and April 2023. The relationship between the operative time in the pelvic phase and clinicopathological data, especially pelvic anatomical parameters measured on X-ray and computed tomography (CT), was evaluated. The operative time in the pelvic phase was defined as the time between mobilization from the sacral promontory and rectal resection.

RESULTS

Robot-assisted low and ultra-low anterior resections were performed in 32 and 29 patients, respectively. The median operative time in the pelvic phase was 126 (range, 31-332) min. A multiple linear regression analysis showed that a short distance from the anal verge to the lower edge of the cancer, a narrow area comprising the iliopectineal line, short anteroposterior and transverse pelvic diameters, and a small angle of the pelvic mesorectum were associated with a prolonged operative time in the pelvic phase.

CONCLUSION

Simple pelvic anatomical measurements using abdominal radiography and CT may predict the pelvic manipulation time in robot-assisted surgery for rectal cancer.

Effect of prolonged operative time on short-term outcomes of open vs minimally invasive proctectomy

BACKGROUND

Minimally invasive proctectomy (MIP) may offer advantages over open proctectomy (OP). Increased operative times (OTs) are linked to inferior outcomes for various operations; however, the interplay between OT and approach for proctectomy is not well-established. This study aimed to evaluate associations of increasing OT on 30-day morbidity in OP and MIP cohorts.

METHODS

The American College of Surgeons National Quality Improvement Program Targeted Proctectomy Dataset was used to identify patients undergoing proctectomy. Cases were stratified by open or minimally invasive surgical approach and following propensity score matching between the groups, and OT quartiles were established for each group. Perioperative outcomes were compared among quartiles, and multivariate regression was used to identify factors associated with prolonged OT.

RESULTS

The median OT was longer for MIP (271 vs 232 min; P < .01). Although increased OT was associated with higher overall morbidity for both open and minimally invasive approaches, this effect was more pronounced in OP than in MIP (63.2% vs 38.4%, respectively; P < .001). Factors associated with prolonged OT included the procedure performed, male sex, higher body mass index scores, diverting ileostomy, and, in malignant disease, mid or lower and T4 tumors (all P < .05).

CONCLUSION

Herein, prolonged OT was associated with worse short-term outcomes for both OP and MIP cases; however, its detrimental effect was more pronounced for open surgery than for minimally invasive surgery. Our data suggested that MIP may offer short-term advantages for demanding cases requiring longer OTs.

Development of artificial blood loss and duration of excision score to evaluate surgical difficulty of total laparoscopic anterior resection in rectal cancer

PURPOSE

Total laparoscopic anterior resection (tLAR) has been gradually applied in the treatment of rectal cancer (RC). This study aims to develop a scoring system to predict the surgical difficulty of tLAR.

METHODS

RC patients treated with tLAR were collected. The blood loss and duration of excision (BLADE) scoring system was built to assess the surgical difficulty by using restricted cubic spline regression. Multivariate logistic regression was used to evaluate the effect of the BLADE score on postoperative complications. The random forest (RF) algorithm was used to establish a preoperative predictive model for the BLADE score.

RESULTS

A total of 1,994 RC patients were randomly selected for the training set and the test set, and 325 RC patients were identified as the external validation set. The BLADE score, which was built based on the thresholds of blood loss (60 ml) and duration of surgical excision (165 min), was the most important risk factor for postoperative complications. The areas under the curve of the predictive RF model were 0.786 in the training set, 0.640 in the test set, and 0.665 in the external validation set.

CONCLUSION

This preoperative predictive model for the BLADE score presents clinical feasibility and reliability in identifying the candidates to receive tLAR and in making surgical plans for RC patients.