Usefulness of an Artificial Intelligence Model in Recognizing Recurrent Laryngeal Nerves During Robot-Assisted Minimally Invasive Esophagectomy.

BACKGROUND: Recurrent laryngeal nerve (RLN) palsy is a common complication in esophagectomy and its main risk factor is reportedly intraoperative procedure associated with surgeons' experience. We aimed to improve surgeons' recognition of the RLN during robot-assisted minimally invasive esophagectomy (RAMIE) by developing an artificial intelligence (AI) model. METHODS: We used 120 RAMIE videos from four institutions to develop an AI model and eight other surgical videos from another institution for AI model evaluation. AI performance was measured using the Intersection over Union (IoU). Furthermore, to verify the AI's clinical validity, we conducted the two experiments on the early identification of RLN and recognition of its location by eight trainee surgeons with or without AI. RESULTS: The IoUs for AI recognition of the right and left RLNs were 0.40 ± 0.26 and 0.34 ± 0.27, respectively. The recognition of the right RLN presence in the beginning of right RLN lymph node dissection (LND) by surgeons with AI (81.3%) was significantly more accurate (p = 0.004) than that by surgeons without AI (46.9%). The IoU of right RLN during right RLN LND recognized by surgeons with AI (0.59 ± 0.18) was significantly higher (p = 0.010) than that by surgeons without AI (0.40 ± 0.29). CONCLUSIONS: Surgeons' recognition of anatomical structures in RAMIE was improved by our AI system with high accuracy. Especially in right RLN LND, surgeons could recognize the RLN more quickly and accurately by using the AI model.

Modification of the lesser curvature incision line enhanced gastric conduit perfusion as determined by indocyanine green fluorescence imaging and decreased the incidence of anastomotic leakage following esophagectomy.

AIM: This study aimed to investigate the effectiveness of a modified incision line on the lesser curvature for gastric conduit formation during esophagectomy in enhancing the perfusion of gastric conduit as determined by indocyanine green fluorescence imaging and reducing the incidence of anastomotic leakage. METHODS: A total of 272 patients who underwent esophagectomy at our institute between 2014 and 2022 were enrolled in this study. These patients were divided based on two different types of cutlines on the lesser curvature: conventional group (n = 141) following the traditional cutline and modified group (n = 131) adopting a modified cutline. Gastric conduit perfusion was assessed by ICG fluorescence imaging, and clinical outcomes after esophagectomy were evaluated. RESULTS: The distance from the pylorus to the cutline was significantly longer in the modified group compared with the conventional group (median: 9.0 cm vs. 5.0 cm, p < 0.001). The blood flow speed in the gastric conduit wall was significantly higher in the modified group than that in the conventional group (median: 2.81 cm/s vs. 2.54 cm/s, p = 0.001). Furthermore, anastomotic leakage was significantly lower (p = 0.024) and hospital stay was significantly shorter (p < 0.001) in the modified group compared with the conventional group. Multivariate analysis identified blood flow speed in the gastric conduit wall as the only variable significantly associated with anastomotic leakage. CONCLUSIONS: ICG fluorescence imaging is a feasible, reliable method for the assessment of gastric conduit perfusion. Modified lesser curvature cutline could enhance gastric conduit perfusion, promote blood circulation around the anastomotic site, and reduce the risk of anastomotic leakage after esophagectomy.

Prognostic Impact of Positive Peritoneal Lavage Cytology on Resectable Pancreatic Body and Tail Cancer: A Retrospective Study.

BACKGROUND: The prognostic impact of positive peritoneal lavage cytology on pancreatic cancer is unclear. Therefore, this study aimed to evaluate its impact in resectable pancreatic body and tail cancer. METHODS: Between January 2006 and December 2019, 97 patients with pancreatic body and tail cancer underwent peritoneal lavage cytology and curative resection at our institution. We analyzed the impact of positive peritoneal lavage cytology on clinicopathological factors and on the prognosis of pancreatic body and tail cancer. RESULTS: Malignant cells were detected in 14 patients (14.4%) using peritoneal lavage cytology. In these patients, the tumor diameter was significantly larger (p < 0.001) and anterior serosal invasion (p = 0.034), splenic artery invasion (p = 0.013), lympho-vessel invasion (p = 0.025), and perineural invasion (p = 0.008) were significantly more frequent. The R1 resection rate was also significantly higher in patients with positive peritoneal lavage cytology than in negative patients (p = 0.015). Positive peritoneal lavage cytology had a significantly poor impact on overall survival (p = 0.001) and recurrence-free survival (p < 0.001). This cytology was also an independent poor prognostic factor for recurrence (p = 0.022) and was associated with peritoneal dissemination and liver metastasis. CONCLUSIONS: Positive peritoneal lavage cytology is considered to be indicative of more systemic disease in patients with resectable pancreatic body and tail cancer than in patients with negative peritoneal lavage cytology. Early detection of pancreatic cancer before it develops micrometastases is important to improve prognosis, and CY+ patients require more intensive multimodality treatment than standard treatment for resectable pancreatic cancer.

Effectiveness of computed tomography scoring for the early diagnosis of anastomotic leakage after esophagectomy.

PURPOSE: Anastomotic leakage after esophagectomy is associated with increased mortality; therefore, early diagnosis is highly important. This study aimed to identify the characteristic computed tomography (CT) findings of cervical anastomotic leakage after esophagectomy for esophageal cancer and evaluate the effectiveness of CT scoring in screening the anastomotic leakage. METHODS: Overall, 91 patients who underwent thoracoscopic esophagectomy with cervical esophago-gastric anastomosis were included. We investigated the correlation between anastomotic leakage and the presence of the microbubble sign, evident air retention, and fluid collection in the cervical and mediastinal regions. CT findings were scored, and the cutoff value was set to 2 points on the receiver operating characteristic curve. The patients were divided into two groups based on the CT score (≥ 2 points and ≤ 1 point). RESULTS: CT findings of the microbubble sign (p = 0.01; odds ratio [OR], 8.545; 95% confidence interval [CI], 1.596-45.73), cervical air retention (p < 0.01; OR, 12.43; 95% CI, 2.084-74.17), and cervical fluid collection (p < 0.01; OR, 9.359; 95% CI, 1.753-49.96) significantly correlated with anastomotic leakage. The ≥ 2-point CT score group showed a significantly higher incidence of anastomotic leakage than the ≤ 1-point group (p < 0.01; OR, 16.28; 95% CI [4.704-56.38]). A ≥ 2-point CT score had higher sensitivity (84.2%) than upper gastrointestinal series (36.8%). CONCLUSION: The presence of microbubble sign, air retention, and fluid collection in the cervical area correlated with anastomotic leakage after cervical anastomosis in thoracoscopic esophagectomy. CT scores are useful early anastomotic leakage detectors.

Usefulness of skeletal muscle measurement by computed tomography in patients with esophageal cancer: changes in skeletal muscle mass due to neoadjuvant therapy and the effect on the prognosis.

PURPOSE: This analysis was performed to clarify the usefulness of skeletal muscle measurements using computed tomography (CT) in patients with esophageal cancer and the effect of treatment-induced changes in the skeletal muscle mass on the prognosis. METHODS: Ninety-seven male patients who underwent thoracoscopic esophagectomy for esophageal squamous cell carcinoma were included in the study. The preoperative CT images were analyzed retrospectively. RESULTS: In a survival analysis performed according to the preoperative data of skeletal muscle, the low-skeletal muscle index (l-SMI) group had a poorer outcome than the normal skeletal muscle index (n-SMI) group in terms of both the overall survival (OS) and the relapse-free survival (RFS) (OS: P < 0.01, RFS: P = 0.01). In the multivariate analysis for the OS, preoperative l-SMI was an independent predictor (hazard ratio: 3.68, 95% confidence interval 1.32-10.2, P = 0.01). In patients who underwent neoadjuvant therapy (NAT), the SMI was significantly reduced after NAT (P < 0.01). The preoperative skeletal muscle area on CT was strongly correlated with the results of a bioelectrical impedance analysis (BIA) (ρ = 0.77, P < 0.01). CONCLUSIONS: A decreased preoperative skeletal muscle mass was associated with a poor outcome. In patients who underwent NAT, the SMI was significantly reduced after NAT. An analysis of the skeletal muscle mass using CT images was found to be useful for providing data that corresponded with BIA data.

Predictive impact of the thoracic inlet space on ICG fluorescence blood flow speed in the gastric conduit wall and anastomotic leakage after esophagectomy.

PURPOSE: The thoracic inlet space might influence the blood vessel perfusion in the gastric conduit. The purpose of this study was to clarify the impacts of the thoracic inlet space on blood vessel perfusion in the gastric conduit and anastomotic leakage after esophagectomy. METHODS: One hundred and forty-two esophageal cancer patients underwent esophagectomy followed by gastric conduit reconstruction via the retrosternal route. The blood flow speed in the gastric conduit was measured using indocyanine green fluorescence before and after reconstruction. Parameters at the thoracic inlet space were measured using CT. We then investigated the correlation between these two parameters and whether they could predict anastomotic leakage after esophagectomy. RESULTS: Blood flow speed in the gastric conduit was slower after reconstruction than before reconstruction (P < 0.001). The incidence of anastomotic leakage (n = 23) was higher among patients with a delayed blood flow speed before reconstruction (n = 27) than among those with a non-delayed blood flow speed before reconstruction (n = 115) (P < 0.001). Among the patients with a non-delayed blood flow speed before reconstruction, the thoracic inlet area (TIA, sternum-tracheal distance × clavicle head distance) was positively correlated with the blood flow speed after reconstruction (P = 0.023) and was identified as an independent predictor of anastomotic leakage (P < 0.001). CONCLUSION: A narrow TIA was associated with a delayed blood flow speed in the gastric conduit after reconstruction and was capable of predicting anastomotic leakage in the patients with a non-delayed blood flow speed before reconstruction.

Internal hernia caused by bridge formation between the medial and lateral segments of the liver: a case report.

BACKGROUND: Despite numerous reports on ischemic bowel obstruction caused by internal hernia, no case presentation has been reported of an internal hernia caused by a bridge formed between the medial and lateral zones of the liver. Herein, we report the first case of ischemic bowel obstruction caused by a hepatic bridge. CASE PRESENTATION: A 24-year-old man complaining of abdominal pain was referred to our hospital and admitted. Computed tomography showed formation of a closed loop of small bowel with a hernia orifice near the hilar region, and poor contrast of the prolapsed small bowel. We suspected ischemic bowel obstruction caused by an internal hernia with a fissure of the greater omentum as the hernia orifice, and performed emergency surgery. Laparoscopic observation revealed that the medial and lateral segments of the liver formed a bridge on the dorsal side at the liver portal, and that the small intestine was ischemic in the gap created between the bridge and the medial and lateral liver segments. A Meckel's diverticulum was also invaginated in the gap. The bridge was dissected out and the hernia orifice was opened to release the bowel obstruction. The small bowel was preserved and the Meckel's diverticulum was resected. The patient's postoperative course was uneventful. CONCLUSIONS: We experienced a case of ischemic bowel obstruction caused by hepatic bridge formation, which was successfully treated by laparoscopic surgery.

Clinicopathological Role of Vasohibin in Gastroenterological Cancers: A Meta-Analysis.

Vasohibin-1 (VASH1) is an angiogenesis inhibitor, while vasohibin-2 (VASH2) is a proangiogenic factor. The roles of VASH1 and VASH2 expression in gastroenterological cancers remain unclear. We searched for relevant literature, specifically studies on gastroenterological cancer, and evaluated the relationship between VASH expression and clinical outcomes. Nine studies on VASH1 involving 1,574 patients were included. VASH1 expression was associated with the TNM stage [OR (odds ratio) 2.05, 95% CI (confidence interval) 1.24-3.40], lymph node metastasis (OR 1.79, 95% CI 1.24-2.58), lymphatic invasion (OR 1.95, 95% CI 1.41-2.68), and venous invasion (OR 2.49, 95% CI 1.60-3.88); poor clinical outcomes were associated with high VASH1 expression. High VASH1 expression was associated with a significantly shorter overall survival (OS) [HR (hazard ratio) 1.69, 95% CI 1.25-2.29] and disease-free survival (DFS) (HR 2.01, 95% CI 1.28-3.15). Three studies on VASH2 involving 469 patients were analyzed. VASH2 expression was associated with the TNM stage (OR 4.21, 95% CI 1.89-9.51) and venous invasion (OR 2.10, 95% CI 1.15-3.84); poor clinical outcomes were associated with high VASH2 expression. High VASH2 expression was associated with a significantly lower OS (HR 1.61, 95% CI 1.09-2.37). In conclusion, high VASH1 and VASH2 expression levels were associated with poor clinical outcomes and prognosis in patients with gastroenterological cancers.

Indocyanine green fluorescence imaging for evaluating blood flow in the reconstructed conduit after esophageal cancer surgery.

We investigated the effectiveness of indocyanine green (ICG) fluorescence blood flow imaging of the gastric conduit to evaluate anastomotic leakage after esophagectomy. We identified 19 articles using the PRISMA standard for systematic reviews. The more recent studies reported attempts at objective quantification of ICG fluorescence imaging, rather than qualitative assessment. Anastomotic leakage after esophagectomy occurred in 0-33% of the patients who underwent ICG fluorescence imaging. According to the six studies that compared the incidence of anastomotic leakage in the ICG group and the control group, it ranged from 0 to 18.3% in the ICG group and from 0 to 25.2% in the control group, respectively. Overall, the incidence of anastomotic leakage in the ICG group (8.4%) was lower than that in the control group (18.5%). Although the incidence of anastomotic leakage was as high as 43.1% in patients who did not undergo any intraoperative intervention for poor blood flow, it was only 24% in patients who underwent intraoperative intervention. This systematic review revealed that ICG fluorescence imaging may be a crucial adjunctive tool for reducing anastomotic leakage after esophagectomy, suggesting that it should be performed during esophageal reconstruction.

Indications for resection of recurrent lesions in patients with distal cholangiocarcinoma based on prognostic factors: a single-institute retrospective study and brief literature review.

BACKGROUND: To evaluate the effectiveness of surgery for recurrent distal cholangiocarcinoma and determine surgical indications based on prognostic factors for the recurrence of distal cholangiocarcinoma. METHODS: We analysed the outcomes of 101 patients who underwent surgical resection for distal cholangiocarcinoma between 2000 and 2018. The clinicopathological factors and prognosis of primary and recurrent distal cholangiocarcinoma were investigated. RESULTS: Of the 101 patients with resected distal cholangiocarcinoma, 52 (51.5%) had relapsed. Seven (13.5%) and 45 patients (86.5%) underwent resection of recurrent lesions and palliative therapy, respectively. There were no major complications requiring therapeutic intervention after metastasectomy. The median overall survival in patients with and without surgery for recurrent lesions was 83.0 (0.0-185.6) and 34 months (19.0-49.0), respectively. Therefore, patients who had undergone surgery for recurrent lesions had a significantly better prognosis (p = 0.022). Multivariate analyses of recurrent distal cholangiocarcinoma revealed that recurrence within one year was an independent predictor of poor survival. Resection of recurrent lesions improved prognosis. CONCLUSIONS: Radical resection in recurrent distal cholangiocarcinoma may improve the prognosis in selected patients. Although time to recurrence is considered an important factor, the small number of cases of recurrence and resection of recurrent lesions in this study makes it difficult to conclude which patients are best suited for resection of recurrent lesions. This issue requires clarification in a multicentre prospective study, considering patients' background, such as the recurrence site and number of metastases.