Automatic preoperative 3d model registration in laparoscopic liver resection.

PURPOSE: : Augmented Reality (AR) in Laparoscopic Liver Resection requires anatomical landmarks and the silhouette to be found on the laparoscopic image. They are used to register the preoperative 3D model obtained from CT segmentation. The existing AR systems rely on the surgeon to 1) annotate the landmarks and silhouette and 2) provide an initial registration. These non-trivial tasks require surgeon attention which may perturb the procedure. We propose methods to solve both tasks, hence registration, automatically. METHODS: : The landmarks are the lower ridge and the falciform ligament. We solve 1) by training a U-Net from a new dataset of 1415 labelled images extracted from 68 procedures. We solve 2) by a novel automatic coarse-to-fine pose estimation method, including visibility-reasoning within an iterative robust process. In addition, we propose to divide the ridge into six anatomical sub-parts, making its annotation and use in registration more accurate. RESULTS: : Our method detects the silhouette with an error equivalent to an experienced surgeon. It detects the ridge and ligament with higher errors owing to under-detection. Nonetheless, our method successfully initialises the registration with tumour target registration errors of 22.4, 14.8 and 7.2 mm for 3 clinical procedures. In comparison, the errors from manual initialisation are 30.5, 15.1 and 16.3 mm. CONCLUSION: : Our results are promising, suggesting that we have found an appropriate methodological approach.

Practical model to identify liver transplant recipients at low risk of postoperative haemorrhage, bile leakage and ascites.

BACKGROUND: This study aimed to identify a subgroup of recipients at low risk of haemorrhage, bile leakage and ascites following liver transplantation (LT). METHODS: Factors associated with significant postoperative ascites (more than 10 ml/kg on postoperative day 5), bile leakage and haemorrhage after LT were identified using three separate multivariable analyses in patients who had LT in 2010-2019. A model predicting the absence of all three outcomes was created and validated internally using bootstrap procedure. RESULTS: Overall, 944 recipients underwent LT. Rates of ascites, bile leakage and haemorrhage were 34.9, 7.7 and 6.0 per cent respectively. The 90-day mortality rate was 7.0 per cent. Partial liver graft (relative risk (RR) 1.31; P = 0.021), intraoperative ascites (more than 10 ml/kg suctioned after laparotomy) (RR 2.05; P = 0.001), malnutrition (RR 1.27; P = 0.006), portal vein thrombosis (RR 1.56; P = 0.024) and intraoperative blood loss greater than 1000 ml (RR 1.39; P = 0.003) were independently associated with postoperative ascites and/or bile leak and/or haemorrhage, and were introduced in the model. The model was well calibrated and predicted the absence of all three outcomes with an area under the curve of 0.76 (P = 0.001). Of the 944 patients, 218 (23.1 per cent) fulfilled the five criteria of the model, and 9.6 per cent experienced postoperative ascites (RR 0.22; P = 0.001), 1.8 per cent haemorrhage (RR 0.21; P = 0.033), 4.1 per cent bile leak (RR 0.54; P = 0.048), 40.4 per cent severe complications (RR 0.70; P = 0.001) and 1.4 per cent 90-day mortality (RR 0.13; P = 0.004). CONCLUSION: A practical model has been provided to identify patients at low risk of ascites, bile leakage and haemorrhage after LT; these patients could potentially qualify for inclusion in non-abdominal drainage protocols.

Intra-versus extracorporeal anastomosis in laparoscopic right colectomy: a meta-analysis of 3699 patients.

BACKGROUND: Laparoscopic right colectomy (LRC) has become a gold standard. However, a major current concern is still whether anastomosis should be performed extracorporeally or entirely laparoscopically. This meta-analysis assesses and compares peri- and postoperative outcomes of intracorporeal anastomosis (IA) versus extracorporeal anastomosis (EA) in LRC. METHODS: The research used the PubMed, Embase and Cochrane databases for studies comparing IA with EA during LRC. Our main endpoint was parietal abscess. Secondary endpoints were 30-day morbidity, mortality, time to onset of gas and stools, length of stay, number of lymph nodes removed and postoperative incisional hernia rates. The MINORS criteria were used to evaluate the quality of the studies examined. RESULTS: Twenty-four articles comprising 3699 patients, published between 2004 and 2020, were included in this meta-analysis. After sensitivity analysis, IA was associated with a decrease in parietal abscesses (OR 0.526, IC 0.333-0.832, p = 0.006). CONCLUSION: This meta-analysis finds that IA allows a decrease in parietal abscesses and time to first gas and stools, surgical repair and length of stay, with similar overall complications.

Intracorporeal versus extracorporeal anastomosis in laparoscopic right hemicolectomy: results from the CLIMHET study group.

BACKGROUND: Laparoscopic right hemicolectomy (LRHC) is increasingly performed for the treatment of right colon disease. Nevertheless, standardization of the surgical technique regarding the performance of intracorporeal (IC) or extracorporeal (EC) anastomosis is lacking. The purpose of this study was to compare short-term postoperative outcomes in patients who had laparoscopic right colectomy either with IC or EC. METHODS: This was a retrospective, non-randomized and multicenter study conducted from January 2005 to December 2015 on the CLIMHET study group cohort from five tertiary centers in France. Data were collected for all patients with LRHC to compare patient characteristics, intraoperative data and postoperative outcomes in terms of medical and surgical complications, duration of hospitalization and mortality. A multivariate analysis was performed to compare the results in the two groups. RESULTS: Of the 597 patients undergoing LRHC, 150 had IC and 447 had EC. The incidence of medical complications (cardiac, vascular, and pulmonary complications) was lower in the IC group than in the EC group (13 vs 20%, p = 0.049). This difference remained significant in multivariate analysis after adjusting to field characteristics and patient histories (p = 0.009). Additionally, a shorter hospital stay (7 vs 8 days, p = 0.003) was observed in the IC group as compared to the EC group. This difference remained significant in favor of the IC group in multivariate analysis (p = 0.029). There was no difference between the groups as regards: surgical complications (p = 0.76), time of mobilization (p = 0.93), reintervention rate (p = 1) and 90-day mortality (p = 0.47). CONCLUSIONS: Our results show that IC anastomosis in LRHC is associated with fewer medical complications and shorter hospital stays compared to EC anastomosis.

Surgical management of gastric adenocarcinoma. Official expert recommendations delivered under the aegis of the French Association of Surgery (AFC).

Gastric adenocarcinoma (GA) is the 5th most common cancer in the world; in France, however, its incidence has been steadily decreasing. Twenty-five experts brought together under the aegis of the French Association of Surgery collaborated in the drafting of a series of recommendations for surgical management of GA. As concerns preoperative evaluation and work-up, echo-endoscopy aimed at clarifying lymph node status should be performed in all candidates for surgical resection and exploratory laparoscopy in cases of GA cT3/T4 and/or N+ for peritoneal carcinomatosis. On the other hand, PET-scan should not be performed systematically, but only when the other modalities for diagnosis prove insufficient. Laparotomy remains the route of choice to achieve total or partial gastrectomy with D2 lymph node lymphadenectomy for advanced lesions (>T2N0). To limit the risk of dumping syndrome and esophageal reflux and as a way of reestablishing continuity, construction of a jejunal pouch on Roux-en-Y following total gastrectomy is recommended. In cases of peritoneal carcinosis in GA with a low peritoneal cancer index (PCI) (<7) in a patient in good general condition whose disease is controlled by chemotherapy, macroscopically complete cytoreduction with intraperitoneal hyperthermal chemotherapy will probably be required, and it will have to take place in an expert center. Only in the event of Child A cirrhosis may gastrectomy with D2 lymphadenectomy be considered. Palliative gastrectomy or surgical bypass for distal stomach obstruction in a patient in good general condition may also be envisioned.

The increasing prominence of "non-surgical" articles in surgical literature.

INTRODUCTION: Publications in the surgical field have usually to do with technical skills (TS). However, the field peripheral to surgical procedures, which brings to bear non-technical skills (NTS) has been achieving increasing prominence. The goal of this study is to objectively assess the evolution of the two fields in surgical literature. METHODS: The authors perused all the articles published over a decade in four large-scale surgical journals and assigned them to the following three categories: (1) TS, (2) NTS or (3) miscellaneous. While the "TS group" included all aspects of surgical procedures, the "NTS group" comprised all aspects of non-surgical perioperative management, and the "miscellaneous group" was composed of all elements extraneous to the first two fields. RESULTS: Of the 8775 articles analyzed, 4326 (49%) belonged to the TS group, 2343 (27%) to the NTS group and 2138 (24%) to the miscellaneous group. There was a significant decrease in the proportion of TS publications [61% in 2007, 44% in 2016 (P<0.001)], accompanied by a significant increase in the proportion of NTS publications (16% in 2007, 34% in 2016 (P<0,001)] over the course of the last decade. The trend first appeared in 2009 and has been confirmed and reinforced over the ensuing years. CONCLUSION: The increasing prominence of non-surgical skills represents a major shift in the editorial choices of high impact surgical journals. It highlights the extent to which the surgical community is manifesting increased interest in the perioperative field, which is now drawing almost as much attention as surgical procedure per se.

BRAF mutation is not associated with an increased risk of recurrence in patients undergoing resection of colorectal liver metastases.

BACKGROUND: BRAF mutation is associated with a poor prognosis in patients with metastatic colorectal cancer. For patients with resectable colorectal liver metastases (CRLMs), the prognostic impact of BRAF mutation is unknown and the benefit of surgery debated. This nationwide intergroup (ACHBT, FRENCH, AGEO) study aimed to evaluate the oncological outcome of patients undergoing liver resection for BRAF-mutated CRLMs. METHODS: The study included patients who underwent resection for BRAF-mutated CRLMs in 24 centres between 2012 and 2016. A case-matched comparison was made with 183 patients who underwent resection of CRLMs with wild-type BRAF during the same interval. RESULTS: Sixty-six patients who underwent resection for BRAF-mutated CRLMs in 24 centres were compared with 183 patients with wild-type BRAF. The 1- and 3-year disease-free survival (DFS) rates were 46 and 19 per cent for the BRAF-mutated group, and 55·4 and 27·8 per cent for the group with wild-type BRAF (P = 0·430). In multivariable analysis, BRAF mutation was not associated with worse DFS (hazard ratio 1·16, 95 per cent c.i. 0·72 to 1·85; P = 0·547). The 1- and 3-year overall survival rates after surgery were 94 and 54 per cent respectively among patients with BRAF mutation, and 95·8 and 82·9 per cent in those with wild-type BRAF (P = 0·004). Median survival after disease progression was 23·0 (95 per cent c.i. 11·0 to 35·0) months among patients with mutated BRAF and 44·3 (35·9 to 52·6) months in those with wild-type BRAF (P = 0·050). Multisite disease progression was more common in the BRAF-mutated group (48 versus 29·8 per cent; P = 0·034). CONCLUSION: These results support surgical treatment for resectable BRAF-mutated CRLM, as BRAF mutation by itself does not increase the risk of relapse after resection. BRAF mutation is associated with worse survival in patients whose disease relapses after resection of CRLM, as for non-metastatic colorectal cancer.

Liver hypertrophy: Underlying mechanisms and promoting procedures before major hepatectomy.

Various procedures can promote hypertrophy of the future liver remnant (FLR) before major hepatectomy to prevent postoperative liver failure. The pathophysiological situation following portal vein embolization (PVE), hepatic artery ligation/embolization or hepatectomy remains unclear. On one hand, the main mechanisms of hepatic regeneration appear to be driven by hepatic hypoxia (involving the hepatic arterial buffer response), an increased portal blood flow inducing shear stress and the involvement of several mediators (inflammatory cytokines, vasoregulators, growth factors, eicosanoids and several hormones). On the other hand, several factors are associated with impaired liver regeneration, such as biliary obstruction, malnutrition, diabetes mellitus, male gender, age, ethanol and viral infection. All these mechanisms may explain the varying degrees of hypertrophy observed following a surgical or radiological procedure promoting hypertrophy the FLR. Radiological procedures include left and right portal vein embolization (extended or not to segment 4), sequential PVE and hepatic vein embolization (HVE), and more recently combined PVE and HVE. Surgical procedures include associated liver partition and portal vein ligation for staged hepatectomy, and more recently the combined portal embolization and arterial ligation procedure. This review aimed to clarify the pathophysiology of liver regeneration; it also describes radiological or surgical procedures employed to improve liver regeneration in terms of volumetric changes, the feasibility of the second step and the benefits and drawbacks of each procedure.

Skin preparation for abdominal surgery.

INTRODUCTION: Surgical site infections (SSI) are a public health issue. The purpose of this review is to review the literature on methods of pre-operative skin preparation for the prevention of SSI in abdominal surgery. METHODS: In order to obtain the best level of evidence, only meta-analyses and randomized controlled clinical trials were selected from the Cochrane Library and PubMed databases. High-powered non-randomized studies were included when results were not available for the questions asked. The primary endpoint was the rate of SSI within 30 days. RESULTS: Analysis of the 20 selected studies suggested that hair removal in the operative field is not recommended except when it interferes with surgery; in this case, hair clipping or chemical depilation is recommended and shaving should be banned. For the pre-operative shower, the choice of a detergent product with or without antiseptic does not seem to matter, and there were no published data on the required number of showers or the interval before surgery. Application of an alcohol-based solution to the operative field for cutaneous disinfection is recommended; the products used seem to be equivalent, and there is no need for pre-operative detergent scrubbing. There is no strong evidence to recommend adhesive plastic drapes for clean or contaminated surgery. CONCLUSION: Some recommendations on skin preparation before abdominal surgery to reduce the rate of SSI are based on a high level of evidence. Other recommendations such as the number and duration of pre-operative showers or use of adhesive plastic skin drapes are less well supported.

Neoadjuvant chemotherapy for initially unresectable intrahepatic cholangiocarcinoma.

BACKGROUND: Locoregional extension of intrahepatic cholangiocarcinoma (ICC) at the time of diagnosis results in a low resectability rate and poor prognosis. The aim of this retrospective study was to assess the efficacy of neoadjuvant chemotherapy for locally advanced ICC. METHODS: All consecutive patients with ICC between 2000 and 2013 were included prospectively in a single-centre database and analysed retrospectively. Patients with locally advanced ICC considered as initially unresectable received primary chemotherapy, followed by surgery in those with secondary resectability. Results of patients who underwent surgery for locally advanced ICC were compared with those of patients with initially resectable ICC treated by surgery alone. RESULTS: A total of 186 patients were included in the study. Of 74 patients with locally advanced ICC, 39 (53 per cent) underwent secondary resection after a median of six chemotherapy cycles. Patients in this group were younger (P = 0·030) and had more advanced disease than those who had surgery alone, and presented more frequently with lymphadenopathy (P = 0·010) and vascular invasion (P = 0·010). Postoperative morbidity and mortality were no different between the groups. The median survival of patients who had surgery after chemotherapy was 24·1 months, and that of patients who had surgery alone was 25·7 months (P = 0·391). CONCLUSION: Patients with locally advanced ICC treated by surgery following neoadjuvant chemotherapy had similar short- and long-term results to patients with initially resectable ICC who had surgery alone. Neoadjuvant chemotherapy as a first-line treatment for locally advanced ICC may be an effective downstaging option, facilitating secondary resectability in patients with initially unresectable disease.

Feasibility prospective study of laparoscopic cholecystectomy with suprapubic approach.

BACKGROUND: Since the publication of laparoscopic cholecystectomy (LC) using three ports instead of four, no significant evolution has impacted on our clinical practice in order to improve length of stay, postoperative pain, time of recovery and cosmetic results. Recently, a renewed interest has been observed with the suprapubic approach, called occult scar laparoscopic cholecystectomy (OSLC). The aim of this prospective multicentric study was to evaluate the feasibility of OSLC in 2 French centers. METHODS: From March to September 2014, 60 patients were prospectively included in this study. The operation incisions consisted of an umbilical incision for camera; an incision in the right groin for maneuvers of exposition and a suprapubic incision for instrumental dissection and clipping. Outcome was by operative time, operative complications, hospital length of stay, analgesia required after surgery, and cosmetic outcomes. The Patient Satisfaction Scale and Visual Analog Score (VAS) also were used to evaluate the level of cosmetic result and postoperative pain. RESULTS: No laparoscopy was converted to an open procedure, the mean operative time was 53±20min. No patient had intraoperative bile duct injury or significant bleeding. The mean length of stay was 1.70±0.76 days. Two patients (3%) experienced postoperative complication (1 intra-abdominal abscess treated by antibiotics and 1 subcutaneous seroma of the 11-mm port wound treated successfully by needle aspiration). CONCLUSION: The technique proved to be safe and feasible with no specific complication and without specific instrument. It offers satisfactory postoperative pain level and good cosmetic results.

The concept of prehabilitation: What the surgeon needs to know?

Despite advances in surgical techniques, anesthesia and perioperative care, which became safer and accessible to a higher proportion of high-risk patients, major surgery remains morbid with a lot of patients not recovering their previous capacity. Indeed surgery is a physiological stress and decreases functional capacity in the postoperative period. A "prehabilitation" program should increase functional capacity in anticipation of an upcoming stress. It should occur after the surgical consultation and before surgery, and is based on three components: physical care, nutritional support and psychological support, during 6 to 8 weeks. The aims of prehabilitation are to improve both nutritional status and pre- and postoperative fitness, and to reduce postoperative complications. Prehabilitation demonstrated benefit on postoperative complications in cardiovascular surgery but its benefit in digestive surgery is still unclear with contradictory results. The aim of this review was to summarize results of prehabilitation on the pre- and postoperative period and to determine its possible future in digestive surgery.

Effects of clamping procedures on central venous pressure during liver resection.

BACKGROUND: Various clamping procedures are used to decrease bleeding during liver resections but their effect on central venous pressure (CVP) remains unclear. The aim of this study was to assess the variations of the CVP during two different clamping procedures. METHODS: We retrospectively reviewed 29 patients (19 males, 10 females) who had Pringle maneuver (PM) and clamping of the inferior vena cava below the liver (IVCC) during major liver resections. RESULTS: Mean decrease of the CVP after PM, IVCC, and PM+IVCC was 0.84 ± 1.37, 2.17 ± 2.13 and 3.17 ± 2.56 cmH20, respectively (P=0.02, P<0.0001 and P<0.0001, respectively). IVCC was more effective in inducing a decrease of the CVP than PM alone (P<0.05). The combination of both PM and IVCC induced the greatest decrease but not to a level of significance compared to IVCC alone (P=0.25). CONCLUSION: IVCC remains the more efficient procedure to lower the CVP. However, although PM is commonly used to control vascular inflow within the liver its significant influence on the CVP could participate to the reduction of bleeding during liver resections.