Robotic versus open resection for colorectal liver metastases in a "referral centre Hub&Spoke learning program". A multicenter propensity score matching analysis of perioperative outcomes.

Background: Surgical resection is still considered the optimal treatment for colorectal liver metastasis (CRLM). Although laparoscopic and robotic surgery demonstrated their reliability especially in referral centers, the comparison between perioperative outcomes of robotic liver resection (RLR) and open (OLR) liver resection are still debated when performed in referral centers for robotic surgery, not dedicated to HPB. Our study aimed to verify the efficacy and safety of perioperative outcomes after RLR and OLR for CRLM in an HUB&Spoke learning program (H&S) between a high volume center for liver surgery and high volume center for robotic surgery. Methods: We analyzed prospective databases of Pineta Grande Hospital (Castel Volturno) and Robotic Surgical Units (Foligno-Spoleto and Arezzo) from 2011 to 2021. A 1:1 propensity score matching (PSM) was performed according to baseline characteristics of patients, solitary/multiple CRLM, anterolateral/posterosuperior location. Results: 383 patients accepted to be part of the study (268 ORL and 115 RLR). After PSM, 45 patients from each group were included. Conversion rate was 8.89 %. RLR group had a significantly lower blood loss (226 vs. 321 ml; p=0.0001), and fewer major complications (13.33 % vs. 17.78 %; p=0.7722). R0 resection was obtained in 100% of OLR (vs.95.55%, p =0.4944. Hospital stay was 8.8 days in RLR (vs. 15; p=0.0001).Conclusion: H&S represents a safe and effective program to train general surgeons also in Hepatobiliary surgery providing R0 resection rate, blood loss volume and morbidity rate superimposable to referral centers. Furthermore, H&S allow a reduction of health mobility with consequent money saving for patients and institutions.

Minimally Invasive Approach to Gastric GISTs: Analysis of a Multicenter Robotic and Laparoscopic Experience with Literature Review.

Background: Gastrointestinal stromal tumors (GISTs) are most frequently located in the stomach. In the setting of a multidisciplinary approach, surgery represents the best therapeutic option, consisting mainly in a wedge gastric resection. (1) Materials and methods: Between January 2010 to September 2020, 105 patients with a primary gastrointestinal stromal tumor (GISTs) located in the stomach, underwent surgery at three surgical units. (2) Results: A multi-institutional analysis of minimally invasive series including 81 cases (36 laparoscopic and 45 robotic) from 3 referral centers was performed. Males were 35 (43.2%), the average age was 66.64 years old. ASA score ≥3 was 6 (13.3%) in the RS and 4 (11.1%) in the LS and the average tumor size was 4.4 cm. Most of the procedures were wedge resections (N = 76; 93.8%) and the main operative time was 151 min in the RS and 97 min in the LS. Conversion was necessary in five cases (6.2%). (3) Conclusions: Minimal invasive approaches for gastric GISTs performed in selected patients and experienced centers are safe. A robotic approach represents a useful option, especially for GISTs that are more than 5 cm, even located in unfavorable places.

Automatic Search-and-Replace From Examples With Coevolutionary Genetic Programming.

We describe the design and implementation of a system for executing search-and-replace text processing tasks automatically, based only on examples of the desired behavior. The examples consist of pairs describing the original string and the desired modified string. Their construction, thus, does not require any specific technical skill. The system constructs a solution to the specified task that can be used unchanged on popular existing software for text processing. The solution consists of a search pattern coupled with a replacement expression: the former is a regular expression which describes both the strings to be replaced and their portions to be reused in the latter, which describes how to build the modified strings. Our proposed system is internally based on genetic programming and implements a form of cooperative coevolution in which two separate populations are evolved independently, one for search patterns and the other for replacement expressions. We assess our proposal on six tasks of realistic complexity obtaining very good results, both in terms of absolute quality of the solutions and with respect to the challenging baselines considered.

Weighted Hierarchical Grammatical Evolution.

Grammatical evolution (GE) is one of the most widespread techniques in evolutionary computation. Genotypes in GE are bit strings while phenotypes are strings, of a language defined by a user-provided context-free grammar. In this paper, we propose a novel procedure for mapping genotypes to phenotypes that we call weighted hierarchical GE (WHGE). WHGE imposes a form of hierarchy on the genotype and encodes grammar symbols with a varying number of bits based on the relative expressive power of those symbols. WHGE does not impose any constraint on the overall GE framework, in particular, WHGE may handle recursive grammars, uses the classical genetic operators, and does not need to define any bound in advance on the size of phenotypes. We assessed experimentally our proposal in depth on a set of challenging and carefully selected benchmarks, comparing the results of the standard GE framework as well as two of the most significant enhancements proposed in the literature: 1) position-independent GE and 2) structured GE. Our results show that WHGE delivers very good results in terms of fitness as well as in terms of the properties of the genotype-phenotype mapping procedure.

The unwanted third wheel in the Calot's triangle: Incidence and surgical significance of caterpillar hump of right hepatic artery with a systematic review of the literature.

BACKGROUND: Caterpillar hump of the right hepatic artery is a rare variation increasing the risk of vascular and biliary injuries during hepatobiliary surgery. The aim of this study is to record the cases of the right hepatic artery forming caterpillar hump in a cohort of patients underwent laparoscopic cholecystectomy and to report a review of the literature systematically conducted. METHODS: We reviewed clinical and surgical video data of 230 patients with symptomatic cholelithiasis treated with laparoscopic cholecystectomy between January 2016 and August 2017. A systematic literature search in PubMed, Medline, Cochrane and Ovid databases until 30th June 2017 was also performed in accordance with the PRISMA statement. RESULTS: Our institutional data indicated that 1.3% of 230 patients presented caterpillar hump right hepatic artery. The systematic review included 16 studies reporting data from a total of 498 human cadavers and 579 patients submitted to cholecystectomy. The overall proportion of surgical patients with the caterpillar hump right hepatic artery was 6.9%. CONCLUSIONS: Variations of the cystic artery are not just an anatomical dissertation, assuming a very crucial role in surgical strategies to avoid uncontrolled vascular lesions. A meticulous knowledge of the hepatobiliary triangle in association with all elements of 'Culture of Safety in Cholecystectomy' is mandatory for surgeons facing more than two structures within Calot's triangle.

Oncologic Effectiveness and Safety of Splenectomy in Total Gastrectomy for Proximal Gastric Carcinoma: Meta-analysis of Randomized Controlled Trials.

BACKGROUND/AIM: The role of splenectomy as an essential component of radical surgery for proximal gastric cancer, from an oncological point of view, is still debated, and no consistent recommendations have been proposed. The aim of this systematic review with meta-analysis was to provide a more robust answer regarding the oncological effectiveness and safety of splenectomy in total gastrectomy for proximal gastric carcinoma. MATERIALS AND METHODS: A systematic review and meta-analysis of randomized controlled trials was planned and performed in accordance with Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement and Cochrane Handbook for Systematic Reviews of Intervention. Patients with a histological diagnosis of gastric adenocarcinoma located in the upper third of the stomach who underwent D2 total gastrectomy with or without splenectomy were selected. The primary outcome was to analyze the influence of splenectomy on the overall survival of patients. Additionally, the mean difference in procedure time, length of hospital stay, number of retrieved lymph nodes, as well as the odds ratio of postoperative complications comparing splenectomy to spleen preservation were investigated in a secondary analysis Results: Overall, four studies with a total of 978 patients met the inclusion criteria. The pooled analysis showed no difference in overall survival rates between those who underwent spleen preservation compared to the splenectomy-treated group (risk ratio=0.92, 95% confidence interval=0.79 to 1.06, p=0.277). Interestingly, all studies reporting overall morbidity data highlighted statistically significant differences in favor of spleen-preservation group (odds ratio=2.11, 95% confidence interval=1.44 to 3.09, p<0.001). CONCLUSION: In total, gastrectomy for proximal gastric cancer, splenectomy should not be recommended as it increases operative morbidity without improving survival when compared to spleen preservation. Furthermore, our results may help in planning the updated versions of Gastric Cancer Treatment Guidelines. This meta-analysis, however, points to the urgent need for high-quality, well-designed, large-scale, clinical trials, with short-as well as long-term evaluation comparing splenectomy with spleen-preserving procedures, in a controlled randomized manner to help future research and to establish an evidence-based approach to gastric cancer treatment.

Active Learning of Regular Expressions for Entity Extraction.

We consider the automatic synthesis of an entity extractor, in the form of a regular expression, from examples of the desired extractions in an unstructured text stream. This is a long-standing problem for which many different approaches have been proposed, which all require the preliminary construction of a large dataset fully annotated by the user. In this paper, we propose an active learning approach aimed at minimizing the user annotation effort: the user annotates only one desired extraction and then merely answers extraction queries generated by the system. During the learning process, the system digs into the input text for selecting the most appropriate extraction query to be submitted to the user in order to improve the current extractor. We construct candidate solutions with genetic programming (GP) and select queries with a form of querying-by-committee, i.e., based on a measure of disagreement within the best candidate solutions. All the components of our system are carefully tailored to the peculiarities of active learning with GP and of entity extraction from unstructured text. We evaluate our proposal in depth, on a number of challenging datasets and based on a realistic estimate of the user effort involved in answering each single query. The results demonstrate high accuracy with significant savings in terms of computational effort, annotated characters, and execution time over a state-of-the-art baseline.

Oncologic Effectiveness and Safety of Bursectomy in Patients with Advanced Gastric Cancer: A Systematic Review and Updated Meta-Analysis.

Purpose/Aim: In the past few decades some researchers have questioned whether bursectomy for gastric cancer is essential from an oncological point of view and no consistent recommendations have been proposed. The aim of this systematic review with meta-analysis is to investigate the oncologic effectiveness and safety of bursectomy for the treatment of advanced gastric cancer patients. MATERIALS AND METHODS: We planned and performed this systematic review and meta-analysis in accordance with Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement and Cochrane Handbook for Systematic Reviews of Intervention. RESULTS: Overall, four studies with a total of 1,340 patients met inclusion criteria. The pooled hazard ratio for overall survival between the bursectomy versus nonbursectomy groups was [HR = 0.85, 95% CI 0.66-1.11, p =.252]. Interestingly, the pooled HR between the two groups in serosa-positive cases subgroup, showed a significant improvement of overall survival rate in favor of bursectomy [HR = 0.72, 95% CI 0.73-0.99, p <.05]. CONCLUSIONS: Bursectomy represents a surgical procedure that might be able to improve overall survival in serosa positive gastric cancer patients. However, a definitive conclusion could not be made because of the studies' methodological limitations. This meta-analysis points to the urgent need of high quality, large-scaled, clinical trials with short- as well as long-term evaluation comparing bursectomy with non bursectomy procedures, in a controlled randomized manner, helping future researches and establishing a modern and tailored approach to gastric cancer.

Robot-assisted versus open liver resection in the right posterior section.

BACKGROUND: Open liver resection is the current standard of care for lesions in the right posterior liver section. The objective of this study was to determine the safety of robot-assisted liver resection for lesions located in segments 6 and 7 in comparison with open surgery. METHODS: Demographics, comorbidities, clinicopathologic characteristics, surgical treatments, and outcomes from patients who underwent open and robot-assisted liver resection at 2 centers for lesions in the right posterior section between January 2007 and June 2012 were reviewed. A 1:3 matched analysis was performed by individually matching patients in the robotic cohort to patients in the open cohort on the basis of demographics, comorbidities, performance status, tumor stage, and location. RESULTS: Matched patients undergoing robotic and open liver resections displayed no significant differences in postoperative outcomes as measured by blood loss, transfusion rate, hospital stay, overall complication rate (15.8% vs 13%), R0 negative margin rate, and mortality. Patients undergoing robotic liver surgery had significantly longer operative time (mean, 303 vs 233 minutes) and inflow occlusion time (mean, 75 vs 29 minutes) compared with their open counterparts. CONCLUSIONS: Robotic and open liver resections in the right posterior section display similar safety and feasibility.

Non-cirrhotic liver tolerance to intermittent inflow occlusion during laparoscopic liver resection.

While inflow occlusion techniques are accepted methods to reduce bleeding during open liver surgery, their use in laparoscopic liver resections are limited by possible effects of pneumoperitoneum on ischemia-reperfusion liver damage. This retrospective study was designed to investigate the impact of intermittent pedicle clamping (IPC) on patients with normal liver undergoing minor laparoscopic liver resections. Three matched groups of patients were retrospectively selected from our in-house database: 11 patients who underwent robot-assisted liver resection with IPC, and 16 and 11 patients who underwent robot-assisted liver resection without IPC and open liver resection with IPC, respectively. The primary end point was to assess differences in postoperative serum alanine, aspartate aminotransferase (ALT and AST) and bilirubin levels. The curves of serum AST, ALT and bilirubin levels in a span of time of five postoperative days were not significantly different between the three groups. IPC has no relevant effects on ischemia-reperfusion liver damage even in the presence of pneumoperitoneum.

Extracorporeal Pringle maneuver in robot-assisted liver surgery.

Hemorrhage is a major complication in laparoscopic liver surgery and inflow occlusion methods are difficult to be reproduced in this setting. This study investigated 10 consecutive patients who underwent robot-assisted liver resection. An extracorporeal Pringle maneuver was carried out encircling the hepato-duodenal ligament using an endowristed robotic arm and exteriorizing the tourniquet at the epigastrium allowing the on-table surgeon to independently control intermittent clamping. The extracorporeal Pringle maneuver was effective and without complications for all patients. The assistant was able to apply consecutive clampings whereas the console surgeon proceeded in parenchyma transection. Robot-assisted liver surgery can be made safer by the use of the extracorporeal Pringle maneuver.

Robot-assisted parenchymal-sparing liver surgery including lesions located in the posterosuperior segments.

OBJECTIVE: The aim of the study is to describe techniques of robot-assisted parenchymal-sparing liver surgery. BACKGROUND: Laparoscopy provides the same oncologic outcomes as open liver resection and better early outcome. Limitations of laparoscopy remain resections in posterior and superior liver segments, frequently approached with laparoscopic right hepatectomy, bleeding from the section line, and prolonged operative times when a combined procedure is needed. METHODS: We retrospectively analyzed our series of robot-assisted liver resections between 2008 and September 2010 to evaluate whether robot assistance can overcome the limitations of laparoscopy. RESULTS: A total of 23 patients underwent robot-assisted liver resection for a total of 21 subsegmentectomies, 6 segmentectomies, 2 segmentectomies S6 + subsegmentectomies S7, 1 bisegmentectomy S2-3, and 2 pericystectomies. In ten cases (47.8%) liver nodules were located in the posterior and superior liver segments. In three cases the tumor was in contact with a main portal branch and in two cases with a hepatic vein. In one case the tumor had contact with both hepatic vein and portal branch. In the latter cases a no-margin resection was carried out. In 16 cases (65.5%) liver resection was associated with a concomitant procedure (10 laparoscopic colectomies, 1 robotic rectal resection, 3 laparoscopic radiofrequency ablations, and 2 extensive adhesiolyses). Mean operative time was 280 ± 101 min, blood loss was 245 ± 254 ml, and mean hospital stay was 8.9 ± 9.4 days. Mortality was nil. One case of biliary leakage and two of intraoperative hemorrhage requiring transfusion were the main complications encountered. CONCLUSIONS: Robot assistance allows optimal access to all liver segments and facilitates parenchymal-sparing surgery also for lesions located in the posterosuperior segments or in contact with main liver vessels.

Robot-assisted laparoscopic management of cardia carcinoma according to Siewert recommendations.

BACKGROUND: Resection of cardia and upper gastric carcinoma is considered a demanding procedure in laparoscopic surgery. Robotics could aid laparoscopic dissection of the oesophago-gastric junction and oesophageal anastomosis, enlarging indications for a minimally invasive approach to these tumours. METHODS: Data from 17 consecutive patients with histologically proved cardia carcinoma were collected in a prospective database to assess the feasibility and safety of laparoscopic robot-assisted radical surgery, using the four-arm da Vinci surgical system. The type of surgery was chosen according to Siewert recommendations. Outcome measures were conversion rate, intra- and post-operative morbidity and mortality, operative time, blood loss, number of lymph nodes harvested and macroscopic and microscopic evaluation of resection margins. RESULTS: Seventeen laparoscopic operations were completed without conversion (14 extended gastrectomies, two transhiatal distal oesophagectomies and one transthoracic distal oesophagectomy). Extended lymph node dissection and oesophago-jejunal anastomosis were successfully carried out using the da Vinci system. Mean operative time was 327.2 ± 93.4 min and blood loss 279 ± 199 ml. The mean number of nodes retrieved was 28 ± 9 and all resection margins were negative. There was no mortality and overall morbidity was acceptably low (41.1%). During a mean follow-up time of 20 months, four recurrences were recorded (two multivisceral, one to the lung and one nodal), with two recurrence-related deaths. CONCLUSIONS: Robot-assisted laparoscopic radical surgery of the oesophago-gastric junction is feasible and safe. Longer follow-up time and randomized studies are needed to evaluate the long-term outcome and advantages for the patient of this new technology.

Laparoscopic resection with intracorporeal anastomosis for colon carcinoma located in the splenic flexure.

BACKGROUND: Treatment of splenic flexure (SF) colon cancer is not standardized. A laparoscopic approach is considered a challenging procedure. METHODS: This review examines a single-institution experience with laparoscopic colon resection for cancer of the SF. Intraoperative, pathologic, and postoperative data of patients who underwent laparoscopic SF resection were reviewed to assess for oncologic safety as well as early- and medium-term outcomes. RESULTS: Between September 2004 and January 2009, laparoscopic SF resection was performed for 15 patients with SF. Two cases of conversion were reported, and for three patients, colonic resection was robot assisted. In all cases, the anastomosis was completed intracorporeally. The distal margin was 3.8 +/- 2.5 cm, and the proximal margin was 7.8 +/- 3.7 cm from the tumor site. The mean number of harvested nodes was 9.2 +/- 5.3. The mean operative time was 183.6 +/- 45 min, and the blood loss was 98 +/- 33 ml. No major morbidity was recorded. CONCLUSIONS: Laparoscopic partial resection seems to be feasible and safe for the treatment of early-stage and locally advanced SF cancer.

Short- and medium-term outcome of robot-assisted and traditional laparoscopic rectal resection.

BACKGROUND: Traditional laparoscopic anterior rectal resection (TLAR) has recently been used for rectal cancer, offering good functional results compared with open anterior resection and resulting in a better postoperative early outcome. However, laparoscopic rectal resection can be technically demanding, especially when a total mesorectal excision is required. The aim of this study was to verify whether robot-assisted anterior rectal resection (RLAR) could overcome limitations of the laparoscopic approach. METHODS: Sixty-six patients with rectal cancer were enrolled in the study. Twenty-nine patients underwent RLAR and 37 TLAR. Groups were matched for age, BMI, sex ratio, ASA status, and TNM stage, and were followed up for a mean time of 12 months. RESULTS: Robot-assisted laparoscopic rectal resection results in shorter operative time when a total mesorectal excision is performed (165.9+/-10 vs 210+/-37 minutes; P<0.05). The conversion rate is significantly lower for RLAR (P<0.05). Postoperative morbidity was comparable between groups. Overall survival and disease-free survival were comparable between groups, even though a trend towards better disease-free survival in the RLAR group was observed. CONCLUSION: RLAR is a safe and feasible procedure that facilitates laparoscopic total mesorectal excision. Randomized clinical trials and longer follow-ups are needed to evaluate a possible influence of RLAR on patient survival.

Laparoscopic and robot-assisted one-stage resection of colorectal cancer with synchronous liver metastases: a pilot study.

BACKGROUND/PURPOSE: One-stage resection of primary colon cancer and synchronous liver metastases is considered an effective strategy of cure. A laparoscopic approach may represent a safe and advantageous choice for selected patients with the aim of improving the early outcome. METHODS: Between January 2008 and October 2008, 7 patients underwent one-stage laparoscopic resection for primary colorectal cancer combined with laparoscopic or robot-assisted liver resection. RESULTS: A total of five laparoscopic left-colon, one right-colon, and one rectal resections were performed. Three patients underwent preoperative left-colon stenting and two received neoadjuvant chemotherapy. The patient with rectal cancer underwent neoadjuvant radiotherapy. Liver procedures included one bisegmentectomy (segments 2, 3), 3 segmentectomies, 6 metastasectomies, and four laparoscopic ultrasound-guided radiofrequency ablations (LUG-RFAs). One patient with multiple liver metastases was managed by a two-stage hepatectomy partially conducted by a totally laparoscopic approach. The overall postoperative morbidity was null. The median hospital stay was 10 days (range 7-10 days). CONCLUSIONS: This pilot study suggests that laparoscopic one-stage colon and liver resection is feasible and safe. Robot assistance may facilitate liver resection, increasing the number of patients who may benefit from a minimally invasive operation.

Robot-assisted laparoscopic total and partial gastric resection with D2 lymph node dissection for adenocarcinoma.

BACKGROUND: Lymph node dissection and esophageal anastomosis, considered the more demanding steps of laparoscopic gastrectomy for gastric adenocarcinoma, can be performed with the use of a remote-controlled robot. METHODS: Thirteen patients with a histologically proved gastric cancer (six stage I, six stage II, and one stage III) were enrolled in a prospective study to assess feasibility and safety of the Da Vinci surgical system in total and partial gastrectomy with extended lymph node dissection. Outcome measures were conversion rate, intra- and postoperative morbidity and mortality, operative time, blood loss, number of lymph nodes harvested, and macroscopic and microscopic evaluation of resection margins. RESULTS: Eight distal, four total, and one proximal laparoscopic gastrectomies were completed without conversion. Extended lymph node dissection, and esophagojejunal and esophagogastric anastomoses were successfully carried out using the da Vinci System. Mean operative time was 286 +/- 32.6 min and blood loss was 103 +/- 87.5 ml. Mean number of nodes retrieved was 28.1 +/- 8.3 and all resection margins were negative. There was no mortality. Trocar bleeding requiring laparoscopy was the only major complication encountered. No recurrence occurred during a mean follow-up time of 12.2 +/- 4.5 months. CONCLUSIONS: Robot-assisted laparoscopic lymph node dissection and esophageal anastomosis are feasible and safe. Longer follow-up time and randomized studies are needed to evaluate long-term outcome and clinical advantages of this new technology.

Comparing fibrin sealant with staples for mesh fixation in laparoscopic transabdominal hernia repair: a case control-study.

BACKGROUND: Laparoscopic hernia repair is not as popular as cholecystectomy. We have performed more than 3,000 laparoscopic herniorrhaphies using the trans-abdominal (TAPP) technique. To prevent recurrences we fix the polypropylene mesh with staples. The use of fibrin glue for graft fixation is a possible alternative. METHODS: We have performed 3,130 laparoscopic hernia repairs over 14 years. For mesh fixation we used titanium clips and observed a small number of complications. In July 2003 we started using fibrin glue (Tissucol(R)). The purpose of this retrospective longitudinal study was to evaluate if the use of fibrin sealant was as safe and effective as conventional stapling and if there were differences in post-operative pain, complications and recurrences. RESULTS: From July 2003 to June 2006 we performed 823 laparoscopic herniorrhaphies. Fibrin glue (Tissucol(R)) was used in 88 cases. Two homogeneous groups of 68 patients (83 cases) treated with fibrin glue and 68 patients (87 cases) where the mesh was fixed with staples, were compared. Patients with relevant associated diseases or large inguino-scrotal hernias were excluded. Operative times were longer in the group treated with fibrin glue with a mean of 35 minutes (range 22-65 mins) compared to the group treated with staples (25 minutes, range 14-50 mins). The time of hospital stay was the same (24 hours). Post-operative complications, that were more frequent in the stapled group, included trocar site pain, hematomas, intra-operative bleedings and incisional hernias. No significant difference was observed concerning seromas, chronic pain and recurrence rate. CONCLUSIONS: Less post-operative pain, and a faster return to usual activities are the main advantages of laparoscopic repair compared to the traditional approach. The use of fibrin sealant reduces in our experience the risk of post- and intra-operative complications such as bleeding and incisional hernia; recurrence rates are similar, but the operative time is longer.