Early-stage clinical evaluation of real-time artificial intelligence assistance for laparoscopic cholecystectomy.

The growing availability of surgical digital data and developments in analytics such as artificial intelligence (AI) are being harnessed to improve surgical care. However, technical and cultural barriers to real-time intraoperative AI assistance exist. This early-stage clinical evaluation shows the technical feasibility of concurrently deploying several AIs in operating rooms for real-time assistance during procedures. In addition, potentially relevant clinical applications of these AI models are explored with a multidisciplinary cohort of key stakeholders.

Risk factors for in-hospital mortality after emergency colorectal surgery in octogenarians: results of a cohort study from a referral center.

PURPOSE: The objective of this study was to investigate predictive factors of mortality in emergency colorectal surgery in octogenarian patients. METHODS: It is a retrospective cohort study conducted at a single-institution tertiary referral center. Consecutive patients who underwent emergency colorectal surgery between January 2015 and January 2020 were identified. The primary endpoint was 30-day mortality. Univariate and multivariate analyses were performed using a logistic regression model. RESULTS: A total of 111 patients were identified (43 men, 68 women). Mean age was 85.7 ± 3.7 years (80-96). Main diagnoses included complicated sigmoiditis in 38 patients (34.3%), cancer in 35 patients (31.5%), and ischemic colitis in 31 patients (27.9%). An ASA score of 3 or higher was observed in 88.3% of patients. The mean Charlson score was 5.9. The Possum score was 35.9% for mortality and 79.3% for morbidity. The 30-day mortality rate was 25.2%. Univariate analysis of preoperative risk factors for mortality shows that the history of valvular heart disease (p = 0.008), intensive care unit provenance (p = 0.003), preoperative sepsis (p < 0.001), diagnosis of ischemic colitis (p = 0.012), creatinine (p = 0.006) and lactate levels (p = 0.01) were significantly associated with 30-day mortality, and patients coming from home had a lower 30-day mortality rate (p = 0.018). Intraoperative variables associated with 30-day mortality included ileostomy creation (p = 0.022) and temporary laparostomy (p = 0.004). At multivariate analysis, only lactate (p = 0.032) and creatinine levels (p = 0.027) were found to be independent predictors of 30-day mortality, home provenance was an independent protective factor (p = 0.004). Mean follow-up was 3.4 years. Survival at 1 and 3 years was 57.6 and 47.7%. CONCLUSION: Emergency colorectal surgery is challenging. However, age should not be a contraindication. The 30-day mortality rate (25.2%) is one of the lowest in the literature. Hyperlactatemia (> 2mmol/L) and creatinine levels appear to be independent predictors of mortality.

End-to-end invaginated pancreaticojejunostomy during minimally invasive pancreatoduodenectomy: technical description and single center experience.

BACKGROUND: Remarkable progress has been made in pancreatic surgery over the last decades with the introduction of minimally invasive techniques. Minimally invasive pancreatoduodenectomy (MIPD) remains one of the most challenging operations in abdominal surgery and it is performed in a few centers worldwide. The treatment of the pancreatic stump is a crucial step of this operation; however, the best strategy to perform pancreatic anastomosis is still debated. In this article, we describe the technical details of our original technique of modified minimally invasive end-to-end invaginated pancreaticojejunostomy (EIPJ) using video footage. METHODS: In the current study, we retrospectively analyzed a pilot series of 67 consecutive cases of minimally invasive (7 robotic/60 fully laparoscopic) MIPD operated on at the General Surgery Department of the Panico Hospital, Tricase (Italy) between March 2017 and October 2022.The reconstruction phase involved an EIPJ, tailored using an intra-ductal anastomotic plastic stent. The aim of this study was to describe the technique and evaluate the short-term outcomes of patients undergoing MIPD with EIPJ. RESULTS: The mean operative time to perform the EIPJ was 21.57 ± 3.32 min. Seven patients (10.5%) developed biochemical leaks and 13 (19.4%) developed clinically relevant pancreatic fistulas (grade B or C according to the definition of the International Study Group on Pancreatic Surgery). CONCLUSION: The early results confirm that this anastomosis is safe, easy to perform, and effective in the hands of hepatobiliopancreatic (HBP) surgeons with experience in minimally invasive surgery.

Laparoscopy-assisted vs open total gastrectomy with D2 lymphadenectomy for advanced gastric cancer: results of a retrospective, multicenter study.

The aim of this study was to retrospectively compare the results of laparoscopy-assisted total gastrectomy (LATG) with those of open total gastrectomy (OTG) for advanced gastric cancer. Patients undergoing total gastrectomy for a T4a, N0-3a-b, M0 gastric adenocarcinoma were divided into two groups. Patients in group A (n = 122) underwent LAG, whereas patients in group B (n = 109) underwent OTG. Mean length of follow-up was 39 months. Primary study's endpoints were postoperative mortality and morbidity, overall late survival (OS) and disease-free survival (DFS). Secondary endpoints were the number of retrieved lymph nodes, operating time, intraoperative blood loss, postoperative length of stay (LOS) and the incidence of local recurrence. Twenty-four patients in group A (19.6%) required conversion into OTG. Postoperative mortality was absent in both groups. Postoperative morbidity was 19% in group A and 11% in group B [p = 0.19]. OS was 34% in group A and 42% in group B [p = 0.21]. DFS was 29% in group A and 33% in group B [p = 0.49]. Mean number of retrieved lymph nodes was 29 in group A and 34 in group B [p < 0.01]. Mean intraoperative blood loss was 230 ml in group A and 180 ml in group B [p = 0.02]. Mean postoperative LOS was 9 days in group A and 11 days in group B [p = 0.09]. Local recurrence was 19% in group A and 13% in group B [p = 0.20]. For advanced gastric cancer, OTG favorably compares with LATG.

One-stage approach to cholecystocholedocholithiasis treatment: a feasible surgical strategy for emergency settings and frail patients.

BACKGROUND: Cholecystocholedocholithiasis (CCL) occurs in up to 18% of patients undergoing laparoscopic cholecystectomy (LC). The two-stage treatment using endoscopic retrograde cholangiopancreatography (ERCP) followed by LC is the treatment of choice for CCL. However, only 10 to 60% of patients have common bile duct (CBD) stones at the time of ERCP, thus exposing patients to unnecessary ERCPs, causing 3 to 15% of post-interventional pancreatitis. One-stage laparoscopic-endoscopic rendezvous (LERV) is an alternative for the treatment of CCL. Given the selective top-to-bottom CBD cannulation, LERV reduces the risk of pancreatitis and failed CBD cannulation. Additionally, LERV is performed exclusively in patients presenting CBD stones at intraoperative cholangiography, avoiding unnecessary ERCPs. Despite its advantages, considering the logistical burden of coordinating different specialties, LERV is performed in few centers. Here, we present the largest retrospective series of LERVs performed at our department, analyzing elective and emergency procedures. METHODS: All consecutive patients undergoing LERV for CCL between January 2014 and December 2021 were included. LERV success rate, operative time, biliary outflow restoration rate, postoperative complications (POC), length of hospital stay (LOS), and recurrences were analyzed. RESULTS: 181 patients were included (61 elective LERVs, 120 emergency LERVs). We reported a 100% LERV success rate, a 97.79% biliary outflow restoration rate, a 0% conversion rate, a mean intraoperative time of 120.17 ± 31.35 min, and LOS of 4.00 ± 2.82 days. POC included 7 Clavien-Dindo type 1, 11 type 2, and 3 type 3 cases. Seven patients presented with CBD stone recurrence: 2 within 30 days after discharge, 3 within 6 months after discharge, and 2 patients at 1 year. No statistically significant difference was found between elective and emergency patients. CONCLUSION: LERV is safe, representing a valid option even in emergency settings, thus enabling the management of CCL within a single procedure, consequently sparing additional anesthesia and decreasing post-ERCP complications.

Intraoperative bowel perfusion quantification with hyperspectral imaging: a guidance tool for precision colorectal surgery.

BACKGROUND: Poor anastomotic perfusion can cause anastomotic leaks (AL). Hyperspectral imaging (HSI), previously validated experimentally, provides accurate, real-time, contrast-free intestinal perfusion quantification. Clinical experience with HSI is limited. In this study, HSI was used to evaluate bowel perfusion intraoperatively. METHODS: Fifty-two patients undergoing elective colorectal surgeries for neoplasia (n = 40) or diverticular disease (n = 12), were enrolled. Intestinal perfusion was assessed with HSI (TIVITA®, Diaspective Vision, Am Salzhaff, Germany). This device generates a perfusion heat map reflecting the tissue oxygen saturation (StO2) amount. Prior to anastomose creation, the clinical transection line (CTL) was highlighted on the proximal bowel and imaged with HSI. Upon StO2 heat map evaluation, the hyperspectral transection line (HTL) was identified. In case of CTL/HTL discrepancy > 5 mm, the bowel was always resected at the HTL. HSI outcomes were compared to the clinical ones. RESULTS: AL occurred in one patient who underwent neoadjuvant radiochemotherapy and ultralow anterior resection for rectal cancer. HSI assessment was feasible in all patients, and StO2-values were significantly higher at proximal segments than distal ones. Twenty-six patients showed CTL/HTL discrepancy, and these patients had a lower mean StO2 (54.55 ± 21.30%) than patients without discrepancy (65.10 ± 21.30%, p = 0.000). Patients undergoing neoadjuvant radiochemotherapy showed a lower StO2 (51.41 ± 23.41%) than non-neoadjuvated patients (60.51 ± 24.98%, p = 0.010). CONCLUSION: HSI is useful in detecting intraoperatively marginally perfused segments, for which the clinical appreciation is unreliable. Intestinal vascular supply is lower in patients undergoing neoadjuvant radiochemotherapy, and this novel finding together with the clinical impact of HSI perfusion quantification deserves further investigation in larger trials.

Development and Validation of a Predictive Model for Internal Hernia After Roux-en-Y Gastric Bypass in a Multicentric Retrospective Cohort: The Swirl, Weight Excess Loss, Liquid Score.

OBJECTIVE: The aim of this study was to develop and validate a prediction score for internal hernia (IH) after Roux-en-Y gastric bypass (RYGB). SUMMARY BACKGROUND DATA: The clinical diagnosis of IH is challenging. A sensitivity of 63% to 92% was reported for computed tomography (CT). METHODS: Consecutive patients admitted for abdominal pain after RYGB and undergoing CT and surgical exploration were included retrospectively. Potential clinical predictors and radiological signs of IH were entered in binary logistic regression analysis to determine a predictive score of surgically confirmed IH in the Geneva training set (January 2006-December 2014), and validated in 3 centers, Geneva (January 2015-December 2017) and Neuchâtel and Strasbourg (January 2012-December 2017). RESULTS: Two hundred twenty-eight patients were included, 80 of whom (35.5%) had surgically confirmed IH, 38 (16.6%) had a negative laparoscopy, and 110 (48.2%) had an alternate diagnosis. In the training set of 61 patients, excess body weight loss >95% (odds ratio [OR] 6.73, 95% confidence interval [CI]: 1.13-39.96), swirl sign (OR 8.93, 95% CI: 2.30-34.70), and free liquid (OR 4.53, 95% CI: 1.08-19.0) were independent predictors of IH. Area under the curve (AUC) of the score was 0.799. In the validation set of 167 patients, AUC was 0.846. A score ≥2 was associated with an IH incidence of 60.7% (34/56), and 5.3% (3/56) had a negative laparoscopy. CONCLUSIONS: The score could be incorporated in the clinical setting. To reduce the risk of delayed IH diagnosis, emergency explorative laparoscopy in patients with a score ≥ 2 should be considered.

Impact of surgical repair on type IV paraesophageal hernias (PEHs).

BACKGROUND: Paraesophageal hernias (PEHs; types II-III-IV) account for about 5% of all hiatal hernias (HHs). The peculiarity of PEHs is the presence of a herniated sac which contains a more or less important part of the stomach, along with other abdominal organs in type IV PEHs. Surgical treatment is more complex since it requires a reduction not only of the herniated content but also of the "container," namely the sac adherent to mediastinal structures. Since type III and IV PEHs are mostly grouped together as large PEHs, there is a lack of articles in the literature with regards to clear surgical outcomes, as well as management algorithms in type IV PEHs. This study aims to compare outcomes in type IV vs. type III PEHs after surgical repair. METHODS: A retrospective study of patients who underwent laparoscopic PEH hernia repair (LPEHR) was conducted in a single institution between 2006 and 2020. Patient baseline characteristics and surgical outcomes were analyzed. RESULTS: A total of 103 patients were included in the analysis. Patients presenting with type IV PEHs (12/103) were significantly older than patients with type III PEHs (91/104) (75.25 ± 7.15 vs. 66.91 ± 13.58 respectively (p = 0.039), and more fragile with a higher Charlson Comorbidity Index (CCI) (4.25 ± 1.48 vs. 2.96 ± 1.72, p = 0.016). Operative time was significantly longer (243 ± 101.73 vs. 133.38 ± 61.76, p = 0.002), and postoperative morbidity was significantly higher in type IV PEH repair (50% vs. 8.8% type III, p = 0.000). CONCLUSION: Patients with type IV PEHs appear to be older and frailer. The higher incidence of postoperative complications in patients with type IV PEHs should advocate for a precise indication for surgical treatment, which should be performed in centers of expertise.

Laparoscopic Versus Open Hartmann Reversal: A Case-Control Study.

BACKGROUND: Laparoscopic reversal of Hartmann's procedure (LHR) offers reduced morbidity compared with open Hartmann's reversal (OHR). The aim of this study is to compare the outcome of laparoscopic versus open Hartmann reversal. MATERIALS AND METHODS: Thirty-four patients who underwent Hartmann reversal between January 2017 and July 2019 were evaluated. Patients underwent either LHR (n = 17) or OHR (n = 17). Variables such as numbers of patients, patient's age, sex, body mass index (BMI), comorbidities, ASA (American Society of Anesthesiology) score, indication for previous open sigmoid resection, mean operation time, rate of conversion to open surgery, length of hospital stay, mortality, and morbidity were retrospectively evaluated. RESULTS: The two groups of patients were homogeneous for gender, age, body mass index, cause of primary surgery, time to reversal, and comorbidities. In 97% of the cases, HP was done by open surgery. Our data revealed no difference in mean operation time (LHR: 180.5 ± 35.1 vs. OHR: 225.2 ± 48.4) and morbidity rate, although, in OHR group, there were more severe complications. Less intraoperative blood loss (LHR: 100 ± 40 mL vs. OHR: 450 ± 125 mL; p value <0.001), shorter time to flatus (LHR: 2.4 days vs. OHR: 3.6 days; p value <0.021), and shorter hospitalization (LHR: 4.4 vs. OHR: 11.2 days; p value <0.001) were observed in the LHR group. Mortality rate was null in both groups. Discussion. LHR is feasible and safe even for patients who received a primary open Hartmann's procedure. We suggest careful patient's selection allowing LHR procedures to highly skilled laparoscopy surgeons.

Autologous peritoneal graft for venous vascular reconstruction after tumor resection in abdominal surgery: a systematic review.

Radical surgical resection (R0) is the only option to cure patients with borderline resectable or multivisceral intraabdominal malignancies involving major vessels. Autologous peritoneal flap has been described as a safe and versatile option for vascular reconstruction, but still limited experience exists regarding its use. An extensive literature review was performed to analyze results of vascular reconstruction with an autologous peritoneal graft. Fifteen reports were found for a total of 94 patients. No cases of arterial vascular reconstruction were found. Two different types of peritoneal patch have been described, backed (APFG, 30 patients) or not backed (ANFP, 64 patients) by posterior rectus sheath. A patch type of reconstruction was adopted in 70 patients (74.5%), while a tubular reconstruction in 24 (25.5%). Postoperative mortality was 5.3% (5 cases). Graft outcomes with very heterogeneous follow-ups (7 days-47 months) were available only in 85 patients (90.4%). Among them, a graft patency was documented in 80 patients (94.1%), while a stenotic graft was reported in 5 patients (5.9%). No differences in graft outcomes were observed between the patch and tubular groups (p = 0.103), nor between the ANFP and APFG groups (p = 0.625). In reported experiences, autologous peritoneal graft seems to represent a safe and versatile option for functional restoration of venous vascular anatomy after resection, especially in operations with high risk of contamination, trauma, liver transplantation and unplanned vascular resection. Unfortunately, the data available in the literature do not make it possible to draw any evidence-based conclusions on these considerations.

6-Month Gastrointestinal Quality of Life (QoL) Results after Endoscopic Sleeve Gastroplasty and Laparoscopic Sleeve Gastrectomy: A Propensity Score Analysis.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is currently the most commonly performed bariatric procedure. Endoscopic sleeve gastroplasty (ESG) is a promising new bariatric technique which is less invasive in its approach. To date no study has compared quality of life (QoL) outcomes between LSG and ESG. The aim of this study is to compare QoL after ESG and LSG using a propensity score analysis. METHODS: QoL was evaluated by means of Gastrointestinal Quality of Life Index (GIQLI) questionnaire before and 6 months after the procedure. Patients were matched for age, sex, preoperative weight, and comorbidities. RESULTS: Propensity score matching resulted in 23 pairs of patients homogeneous for age (p = 0.3), preoperative BMI (p = 0.3), sex (p = 0.74), and comorbidities (p = 0.9). Post-ESG patients, despite a less important %EWL (39.9 (17.5-58.9)vs 54.9 (46.2-65); p = 0.01) and %TWL (13.4 (7.8-20.9) vs 18.8 (17.6-21.8); p = 0.03), presented better QoL (14 [3-24] vs 13 (- 1-23) ΔGIQLI score; p = 0.79) with clear advantage for the gastrointestinal symptoms subdomain (66.5 (61-70.5) vs 59 (55-63); p = 0.001), while post-LSG patients presented a worsening of GERD symptoms (30.7% vs 0%) and an increased use of PPI therapy (p = 0.004). Resolution or improvement of comorbidities was similar (ESG 53% vs LSG 45.8%; p = 0.79) in both groups. CONCLUSION: LSG may significantly affect QoL and results in worsening of gastrointestinal symptoms including GERD. ESG is a promising less invasive bariatric endoscopic procedure that demonstrated a positive impact on both QoL and comorbidities, which could lead to greater patient acceptance earlier in their disease or at a younger age.

Does endoscopic sleeve gastroplasty stand the test of time? Objective assessment of endoscopic ESG appearance and its relation to weight loss in a large group of consecutive patients.

INTRODUCTION: Endoscopic sleeve gastroplasty (ESG) is a promising bariatric treatment. Gastric volume reduction and delayed gastric emptying are the probable mechanisms driving weight loss. However, there are concerns regarding the overtime ESG effectiveness. This study aims to evaluate the correlation between endoscopic gastroplasty integrity overtime and weight loss. PATIENTS AND METHODS: Patients undergoing follow-up endoscopy (6 and 12 months) after ESG were included. ESG were classified in three groups according to endoscopic appearance: open when all the stiches were loose; partially intact if at least one stitch was loose; intact if all the stitches were present and tight. Initial BMI, excess weight loss (%EWL) and total weight loss (%TWL) at 6 and 12 months were assessed against gastroplasty endoscopic appearance. RESULTS: From October 2016 to April 2019, 133 patients underwent ESG, 87 (65.4%) had a follow-up EGD at 6 months. ESG was open in six cases (6.9%), partially intact in 38 (43.7%) and intact in 43 (49.4%). The overall %EWL and %TWL was 34.5 ± 19.8 and 13.2 ± 7.4, respectively; 25.7 ± 26.9 and 11.8 ± 11.8 for the open group, 30.8 ± 20.1 and 12.4 ± 7.8 for the partially intact group; 39.1 ± 19.7 and 14.0 ± 6.4 for the intact gastroplasty. Forty-one patients underwent a 12 months endoscopy: 10 (24.4%) had an intact ESG, 24 (58.5%) had a partially intact gastroplasty, and in 7 (17.0%) cases the sutures were lost. Overall %EWL and %TWL at 12 months was 34.3 ± 21.9 and 13.1 ± 8.1: 19.3 ± 13.4 and 8.9 ± 6.1 for the open group; 36.0 ± 24.2 and 13.1 ± 8.9 for the partially intact group; 40.3 ± 17.3 and 17.2 ± 5.4 for the intact group. ESG appearance correlated with preoperative BMI (r 0.34; p 0.001) and %EWL at 6 months (r 0.22; p 0.035) and 12 months (r 0.29; p 0.065). CONCLUSION: This preliminary work shows that weight loss correlates with ESG endoscopic appearance over time. Initial BMI predicts endoscopic suture duration over time. Larger studies and longer follow-up are needed.

Full Robotic Distal Pancreatectomy: Safety and Feasibility Analysis of a Multicenter Cohort of 236 Patients.

Introduction. Despite the widespread use of the robotic technology, only a few studies with small sample sizes report its application to pancreatic diseases treatment. Our aim is to present the results of a multicenter study on the safety and feasibility of robot-assisted distal pancreatectomy (RDP). Materials and Methods. All RDPs for benign, borderline, and malignant diseases performed in 5 referral centers from 2008 to 2016 were included. Perioperative outcomes were evaluated. Results. Two hundred thirty-six patients were included. Spleen preservation was performed in 114 cases (48.3%). Operative time was 277.8 ± 93.6 minutes. Progressive improvement in operative time was observed over the study period. Conversion rate was 6.3%. Morbidity occurred in 102 cases (43.2%), mainly due to grade A fistulas. Reoperation was required in 10 patients. Postoperatively, 2 patients died of sepsis due to a grade C fistula. Hospital readmission was necessary in 11 cases. A R0 resection was always achieved, with a mean number of 16.2 ± 15 harvested lymph nodes. Conclusion. To our knowledge, this is one of the largest RDP series. Safety and feasibility including the low conversion rate, the high spleen preservation rate, the adequate operative time, and the acceptable morbidity and mortality rates confirm the validity of this technique. Appropriate oncological outcomes have been also obtained.

Hybrid fluorescent magnetic gastrojejunostomy: an experimental feasibility study in the porcine model and human cadaver.

BACKGROUND: Laparoscopic gastrojejunostomies are time consuming and require a specific training. Alternatively, sutureless anastomosis can be achieved using endoscopically delivered magnetic rings. Our aim was to assess the feasibility and reproducibility of an endo-laparoscopic gastrojejunostomy technique, using a pair of magnets coated with a near-infrared fluorescent biocompatible polymeric material. METHODS: Five pigs (3 acute and 2 survival models) and one human anatomical specimen were included. In the survival models, the distal ring was inserted into the duodenum endoscopically, and it was fixed to a thread clipped to the gastric mucosa. Twenty-four hours later, a two-port laparoscopy was performed using a near-infrared (NIR) laparoscope. The magnet position in the jejunum was detected with the transluminal fluorescence of the dye. Magnetic interaction with the metallic tip of the laparoscopic grasper allowed to capture the ring and bring the bowel loop to the future anastomotic site on the gastric wall. The proximal magnet was inserted into the stomach endoscopically and released when magnetic interaction started, allowing for a precise connection with the distal ring. The animals were followed up for 12 days and underwent control endoscopies and radiograms. In the acute animals, the anastomotic procedure was repeated 24 times. Finally, the procedure was performed in the human anatomical specimen. RESULTS: There were no technical problems, and magnetic connection could be precisely directed at both the anterior and posterior gastric walls. No complications occurred during the survival period and the anastomoses were patent on day 5. Transluminal fluorescence enabled a rapid detection of the magnet. CONCLUSIONS: Hybrid-reduced port magnetic gastrojejunostomy using a pair of fluorescently coated magnetic rings was feasible, reproducible, and easy to perform in both porcine and cadaver models.

Simultaneous computer-assisted assessment of mucosal and serosal perfusion in a model of segmental colonic ischemia.

BACKGROUND: Fluorescence-based enhanced reality (FLER) enables the quantification of fluorescence signal dynamics, which can be superimposed onto real-time laparoscopic images by using a virtual perfusion cartogram. The current practice of perfusion assessment relies on visualizing the bowel serosa. The aim of this experimental study was to quantify potential differences in mucosal and serosal perfusion levels in an ischemic colon segment. METHODS: An ischemic colon segment was created in 12 pigs. Simultaneous quantitative mucosal and serosal fluorescence imaging was obtained via intravenous indocyanine green injection (0.2 mg/kg), using two near-infrared camera systems, and computer-assisted FLER analysis. Lactate levels were measured in capillary blood of the colonic wall at seven regions of interest (ROIs) as determined with FLER perfusion cartography: the ischemic zone (I), the proximal and distal vascularized areas (PV, DV), and the 50% perfusion threshold proximally and distally at the mucosal and serosal side (P50M, P50S, D50M, D50S). RESULTS: The mean ischemic zone as measured (mm) for the mucosal side was significantly larger than the serosal one (56.3 ± 21.3 vs. 40.8 ± 14.9, p = 0.001) with significantly lower lactate values at the mucosal ROIs. There was a significant weak inverse correlation between lactate and slope values for the defined ROIs (r = - 0.2452, p = 0.0246). CONCLUSIONS: Mucosal ischemic zones were larger than serosal zones. These results suggest that an assessment of bowel perfusion from the serosal side only can underestimate the extent of ischemia. Further studies are required to predict the optimal resection margin and anastomotic site.

Correction to: Discrimination between arterial and venous bowel ischemia by computer-assisted analysis of the fluorescent signal.

In the original version, Ines Gockel was omitted as a coauthor. The complete author listing is corrected here.

Discrimination between arterial and venous bowel ischemia by computer-assisted analysis of the fluorescent signal.

BACKGROUND: Arterial blood supply deficiency and venous congestion both play a role in anastomotic complications. Our aim was to evaluate a software-based analysis of the fluorescence signal to recognize the patterns of bowel ischemia. METHODS: In 18 pigs, two clips were applied on the inferior mesenteric artery (group A: n = 6) or vein (group V: n = 6) or on both (group A-V: n = 6). Three regions of interest (ROIs) were identified on the sigmoid: P = proximal to the first clip; C = central, between the two clips; and D = distal to the second clip. Indocyanine Green was injected intravenously. The fluorescence signal was captured by means of a near-infrared laparoscope. The time-to-peak (seconds) and the maximum fluorescence intensity were recorded using software. A normalized fluorescence intensity unit (NFIU: 0-to-1) was attributed, using a reference card. The NFIU's over-time variations were computed every 10 min for 50 min. Capillary lactates were measured on the sigmoid at the 3 ROIs. Various machine learning algorithms were applied for ischemia patterns recognition. RESULTS: The time-to-peak at the ischemic ROI C was significantly longer in group A versus V (20.1 ± 13 vs. 8.43 ± 3.7; p = 0.04) and in group A-V versus V (20.71 ± 11.6 vs. 8.43 ± 3.7; p = 0.03). The maximal NIFU at ROI C, was higher in the V group (1.01 ± 0.21) when compared to A (0.61 ± 0.11; p = 0.002) and A-V (0.41 ± 0.2; p = 0.0005). Capillary lactates at ROI C were lower in V (1.3 ± 0.6) than in A (1.9 ± 0.5; p = 0.0071), and A-V (2.6 ± 1.5; p = 0.034). The K nearest neighbor and the Linear SVM algorithms provided both an accuracy of 75% in discriminating between A versus V and 85% in discriminating A versus A-V. The accuracy dropped to 70% when the ML had to identify the ROI and the type of ischemia simultaneously. CONCLUSIONS: The computer-assisted dynamic analysis of the fluorescence signal enables the discrimination between different bowel ischemia models.

Virtual and Augmented Reality in Oncologic Liver Surgery.

Virtual reality (VR) and augmented reality (AR) in complex surgery are evolving technologies enabling improved preoperative planning and intraoperative navigation. The basis of these technologies is a computer-based generation of a patient-specific 3-dimensional model from Digital Imaging and Communications in Medicine (DICOM) data. This article provides a state-of-the- art overview on the clinical use of this technology with a specific focus on hepatic surgery. Although VR and AR are still in an evolving stage with only some clinical application today, these technologies have the potential to become a key factor in improving preoperative and intraoperative decision making.