Radical en bloc peritonectomy in advanced ovarian cancer

Exploring the Potential Role of Upper Abdominal Peritonectomy in Advanced Ovarian Cancer Cytoreductive Surgery Using Explainable Artificial Intelligence

The Surgical Complexity Score (SCS) has been widely used to describe the surgical effort during advanced stage epithelial ovarian cancer (EOC) cytoreduction. Referring to a variety of multi-visceral resections, it best combines the numbers with the complexity of the sub-procedures. Nevertheless, not all potential surgical procedures are described by this score. Lately, the European Society for Gynaecological Oncology (ESGO) has established standard outcome quality indicators pertinent to achieving complete cytoreduction (CC0). There is a need to define what weight all these surgical sub-procedures comprising CC0 would be given. Prospectively collected data from 560 surgically cytoreduced advanced stage EOC patients were analysed at a UK tertiary referral centre.We adapted the structured ESGO ovarian cancer report template. We employed the eXtreme Gradient Boosting (XGBoost) algorithm to model a long list of surgical sub-procedures. We applied the Shapley Additive explanations (SHAP) framework to provide global (cohort) explainability. We used Cox regression for survival analysis and constructed Kaplan-Meier curves. The XGBoost model predicted CC0 with an acceptable accuracy (area under curve [AUC] = 0.70; 95% confidence interval [CI] = 0.63-0.76). Visual quantification of the feature importance for the prediction of CC0 identified upper abdominal peritonectomy (UAP) as the most important feature, followed by regional lymphadenectomies. The UAP best correlated with bladder peritonectomy and diaphragmatic stripping (Pearson's correlations > 0.5). Clear inflection points were shown by pelvic and para-aortic lymph node dissection and ileocecal resection/right hemicolectomy, which increased the probability for CC0. When UAP was solely added to a composite model comprising of engineered features, it substantially enhanced its predictive value (AUC = 0.80, CI = 0.75-0.84). The UAP was predictive of poorer progression-free survival (HR = 1.76, CI 1.14-2.70, P: 0.01) but not overall survival (HR = 1.06, CI 0.56-1.99, P: 0.86). The SCS did not have significant survival impact. Machine Learning allows for operational feature selection by weighting the relative importance of those surgical sub-procedures that appear to be more predictive of CC0. Our study identifies UAP as the most important procedural predictor of CC0 in surgically cytoreduced advanced-stage EOC women. The classification model presented here can potentially be trained with a larger number of samples to generate a robust digital surgical reference in high output tertiary centres. The upper abdominal quadrants should be thoroughly inspected to ensure that CC0 is achievable.

Surgical Anatomy of the Liver-Significance in Ovarian Cancer Surgery

INTRODUCTION

Ovarian cancer is the leading cause of death among all gynecological malignancies. Most patients present with an advanced stage of the disease. The routes of spread in ovarian cancer include peritoneal dissemination, direct invasion, and lymphatic or hematogenous spread, with peritoneal and lymphatic spread being the most common among them. The flow direction of the peritoneal fluid makes the right subphrenic space a target site for peritoneal metastases, and the most frequently affected anatomical area in advanced cases is the right upper quadrant. Complete cytoreduction with no macroscopically visible disease is the most important prognostic factor.

METHODS

We reviewed published clinical anatomy reports associated with surgery of the liver in cases of advanced ovarian cancer.

RESULTS

The disease could disseminate anatomical areas, where complex surgery is required-Morrison's pouch, the liver surface, or porta hepatis. The aim of the present article is to emphasize and delineate the gross anatomy of the liver and its surgical application for oncogynecologists. Moreover, the association between the gross and microscopic anatomy of the liver is discussed. Additionally, the vascular supply and variations of the liver are clearly described.

CONCLUSIONS

Oncogynecologists performing liver mobilization, diaphragmatic stripping, and porta hepatis dissection must have a thorough knowledge of liver anatomy, including morphology, variations, functional status, potential diagnostic imaging mistakes, and anatomical limits of dissection.

Narrative review of liver mobilization, diaphragm peritonectomy, full-thickness diaphragm resection, and reconstruction

Epithelial ovarian cancer is the most lethal among gynecologic cancers. Despite advances in research efforts to cure this disease, the recurrence and survival rates have not significantly improved. Primary cytoreductive surgery and adjuvant chemotherapy are the standard treatment options for patients with epithelial ovarian cancer. Two randomized trials recently introduced neoadjuvant chemotherapy followed by interval cytoreductive surgery as an alternative treatment option. In any case, the size of the residual tumor after surgery is the most important prognostic factor for patients with ovarian cancer. With the improvement of surgical techniques in gynecologic oncology, cytoreductive surgery is now performed for the pelvic area and entire abdomen. Currently, surgical resectability of a mass spreading into the upper abdomen is the most important factor for achieving optimal cytoreduction. In this study, we explain the procedure of a cytoreductive surgery, involving the resection of a tumor located in the upper abdomen. We aimed to review and describe the surgical techniques involved in liver mobilization, diaphragm peritonectomy, and full-thickness diaphragm resection and reconstruction. Further, we have assessed the postoperative care involved and discussed complications that may possibly arise along with suggestions to avoid them based on the review of previous literature on the subject.