Evaluating the benefit of contact-force feedback in robotic surgery using the Saroa surgical system: A preclinical study.

INTRODUCTION: Robotic surgery without contact-force feedback could be less safe, as forces exerted by the robot system may exceed tissue tolerance. This study aimed to evaluate the benefit of contact-force feedback. METHODS: Nine junior and 11 senior surgeons performed two tasks using Saroa, a robotic surgical system with a force feedback function. In Task A, the participants estimated the order of stiffness of substances when feedback was on and off. In Task B, the effect of feedback on compression with a designated force (3 N) was assessed. RESULTS: In Task A, the proportion of participants who correctly estimated the order of stiffness of the substances was similar when feedback was on and off. However, the median maximum force applied to the substances was significantly smaller when feedback was on than when it was off (5.0 vs. 6.9 N, p = .011), which was more obvious among the junior surgeons (5.0 vs. 7.7 N, p = .015) than among the senior surgeons (4.7 vs. 5.9 N, p = .288). In Task B, deviations from the designated force (3 N) for three substances were smaller when feedback was on (0, -0.1, and 0.7, respectively) than when it was off (-0.3, -0.5, and 1.3, respectively). Regarding the dispersion of the force to the substances, the interquartile range tended to be smaller with feedback; this trend was more obvious in the junior surgeons. CONCLUSION: With contact-force feedback, tissue stiffness could be estimated with a small force, particularly by the junior surgeons; specified force could be accurately applied to the tissue.

Lipid Peroxidation Regulators GPX4 and FSP1 as Prognostic Markers and Therapeutic Targets in Advanced Gastric Cancer.

Gastric cancer is one of the most common cancers worldwide, and new therapeutic strategies are urgently needed. Ferroptosis is an intracellular iron-dependent cell death induced by the accumulation of lipid peroxidation, a mechanism different from conventional apoptosis and necrosis. Therefore, induction of ferroptosis is expected to be a new therapeutic strategy. Glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1) have been identified as the major inhibitors of ferroptosis. Herein, we performed immunohistochemistry for GPX4, FSP1, and 4-HNE using tissues from patients with gastric cancer and investigated the relationship between these factors and prognosis. Patients with high GPX4 expression or high GPX4 expression and low 4-HNE accumulation tended to have a poor prognosis (p = 0.036, 0.023), whereas those with low FSP1 expression and high 4-HNE accumulation had a good prognosis (p = 0.033). The synergistic induction of cell death by inhibiting GPX4 and FSP1 in vitro was also observed, indicating that the cell death was non-apoptotic. Our results indicate that the expression and accumulation of lipid peroxidation-related factors play an important role in the clinicopathological significance of gastric cancer and that novel therapeutic strategies targeting GPX4 and FSP1 may be effective in treating patients with gastric cancer who have poor prognosis.

Blood flow assessment of gastric tube with indocyanine green fluorescence angiography and postoperative endoscopy during esophagectomy: indocyanine green enhancement time indicated congestion.

BACKGROUND: During esophagectomy, evaluation of blood supply to the gastric tube is critically important to estimate and avoid anastomotic complications. This retrospective study investigated the relationship between indocyanine green (ICG) fluorescence angiography during esophagectomy and postoperative endoscopy findings, especially mucosal color change. METHODS: This study retrospectively collected data from 86 patients who underwent subtotal esophagectomy and reconstruction using a gastric tube for esophageal cancer at the Tokyo Medical and Dental University between 2017 and 2020. The flow speed of ICG fluorescence in the gastric tube was evaluated during the operation. Additionally, the main root of ICG enhancement and pattern of ICG distribution in the gastric tube were evaluated. On postoperative day 1 (POD1), the change in the mucosal color to white, thought to reflect ischemia, or black, thought to reflect congestion of the proximal gastric tube, was evaluated. The correlations between these factors, clinical parameters, and surgical outcomes were evaluated. Univariate and multivariate analyses used logistic regression to identify the risk factors affecting mucosal color change. RESULTS: Multivariate analyses revealed that the only independent significant predictor of mucosal congestion on POD1 was the ICG enhancement time of the right gastric tube tip (odds ratio, 14.49; 95% confidential interval, 2.41-87.24; P = 0.004). CONCLUSIONS: This study indicated that the ICG enhancement time is related to venous malperfusion and congestion rather than arterial malperfusion and ischemia.

Intraoperative Recurrent Laryngeal Nerve Monitoring for Esophagectomy: A National Cohort Study.

BACKGROUND: Lymphadenectomy around the recurrent laryngeal nerve (RLN) is an essential part of curative surgery for esophageal cancer. Although several single-center studies have shown that intraoperative nerve monitoring (IONM) can avoid RLN palsy, this has not been confirmed in a large-scale multicenter study. This study used a national database to evaluate whether IONM can reduce postoperative RLN palsy during minimally invasive esophagectomy (MIE) for esophageal cancer. METHODS: We retrieved data of patients with esophageal cancer who underwent 3-field thoracoscopic or robotic MIE with cervical anastomosis with IONM(+) (502 patients) and without IONM(-) (4353 patients) from April 2020 to March 2022 from the Diagnosis Procedure Combination database in Japan. We used propensity score-matching analysis to compare the frequency of postoperative RLN palsy and respiratory complications between the IONM(+) group and IONM(-) group. RESULTS: The postoperative RLN palsy rate was significantly lower in the IONM(+) than IONM(-) group (odds ratio, 0.24; 95% CI, 0.13-0.46). The respiratory complication rate was also significantly lower in the IONM(+) than in the IONM(-) group (odds ratio, 0.66; 95% CI, 0.45-0.97). The anesthesia time was significantly longer in the IONM(+) group (regression coefficient, 60.1 minutes; 95% CI, 44.2-76.9 minutes). The length of postoperative hospitalization tended to be shorter in the IONM(+) than in the IONM(-) group (regression coefficient, -1.39 days; 95% CI, -3.91 to 1.14). CONCLUSIONS: This national cohort study showed that IONM during 3-field MIE for esophageal cancer was associated with a reduction of postoperative RLN palsy and respiratory complications.

Effects of a force feedback function in a surgical robot on the suturing procedure.

BACKGROUND: Currently, widely used robotic surgical systems do not provide force feedback. This study aimed to evaluate the impact and benefits of a force feedback function on the suturing procedure. METHODS: Twenty surgeons were recruited and divided into young (Y-group, n = 11) and senior (S-group, n = 9) groups, based on their years of surgical experience. The effect of the force feedback function on suturing quality was evaluated using an objective assessment system (A-LAP mini, Kyoto Kagaku Co., Ltd., Kyoto, Japan). Each participant completed the suturing task on intestinal model sheets with the robotic contact force feedback on and off. The task accomplishment time (s), maximal force (Newton, N) applied to the robotic forceps, and quality of suturing (assessed by A-LAP mini) were recorded as performance parameters. RESULTS: In total, the maximal force applied to the robotic forceps was significantly decreased with the robotic force feedback switched on (median [interquartile range]: 2.8 N (2.3-3.2)) as compared with when the feedback was switched off (3.4 N (2.7-4.0), P < 0.001). The contact force feedback function did not affect the objectively assessed suturing score (18 points (17.7-19.0) versus 18 points (17.0-19.0), P = 0.421). The contact force feedback function slightly shortened the task accomplishment time in the Y-group (552.5 s (466.5-832) versus 605.5 s (476.2-689.7), P = 0.851) but not in the S-group (566 s (440.2-703.5) versus 470.5 s (419.7-560.2), P = 0.164). CONCLUSIONS: With the contact force feedback function, the suturing task was completed with a smaller maximal force, while maintaining the quality of suturing. Because the benefits are more apparent in young surgeons, robots with the contact force feedback function will facilitate the educational process in novice surgeons.

[A Case of Specific Pneumonia Diagnosed as Peritumoral Infiltration during Nivolumab Treatment for Esophageal Cancer].

The patient is a 54-year-old man who was diagnosed with advanced unresectable esophageal cancer. He underwent three courses of FP therapy and was followed up for observation after chemoradiotherapy and PR. Metastasis appeared in the upper lobe of the left lung and new lung metastasis was found in the lower lobe of the right lung despite FP therapy 2 years and 1 month after the start of treatment. Nedaplatin and docetaxel were administered as a second-line chemotherapy; however, the lung metastasis worsened. Consequently, nivolumab was introduced as a third-line chemotherapy. The metastases in the lower lobe of the right lung disappeared with pneumonia after 6 courses of nivolumab, which was diagnosed as a peritumoral infiltration(PTI). PTI is difficult to distinguish from drug-induced lung injury and should be diagnosed carefully because it is an imaging finding that reflects the desired antitumor effect.

Optimal placement of self-fixating mesh in the rectus abdominis muscle for ventral hernia repair when using the enhanced-view totally extraperitoneal Rives-Stoppa technique.

INTRODUCTION: Laparoscopic retro-muscular Rives-Stoppa (RS) ventral hernia repair using the enhanced-view totally extraperitoneal (eTEP) technique (eTEP-RS) is becoming common. Although self-fixating mesh is useful with good fixation, some surgeons think the fixating surface must be oriented towards the rectus abdominis muscle for safety reasons in eTEP-RS. Attaching the self-fixating mesh to the rectus abdominis, the ceiling of the operative field, is challenging and time-consuming. MATERIAL AND SURGICAL TECHNIQUE: First, the self-fixating mesh is folded in half with the fixation surface facing outwards. Second, we create a partition sheet and insert the sheet between the two arms of the folded mesh. The folded mesh is then inserted intracorporeally. We can unfold the mesh easily from one-quarter width to half width on the rectus abdominis muscle because of the insertion of the partition sheet. Finally, the mesh is unfolded to full width, and the mesh placement is completed. DISCUSSION: The eTEP-RS is still a new procedure and has not yet been standardized. However, our technique will increase the use of self-fixating mesh and improve the outcomes of eTEP-RS.

Left thoracoscopic approach in the supine position for torsion of the residual esophagus after esophagectomy: a case report.

BACKGROUND: Anastomotic stenosis can occur after esophagectomy and gastric tube reconstruction. The effective surgical treatment for refractory anastomotic stenosis, which seems difficult to resolve with endoscopic treatment, has not been established. We report a case of refractory stenosis due to esophageal torsion in which reconstructive surgery was possible using a left thoracoscopic approach in the supine position. CASE PRESENTATION: A 72-year-old man who underwent thoracoscopic subtotal esophagectomy and retrosternal gastric tube reconstruction for esophageal cancer 6 months previously presented to us. Postoperative endoscopy revealed that the residual esophagus was twisted approximately 360°, just above the anastomotic site. Conservative endoscopic treatment failed to improve the condition due to severe passage obstruction, and reconstructive surgery was repeated. Surgery was performed in the supine position using a left thoracoscopic approach. The entire circumferences of the gastric tube and residual esophagus were dissected from the inferior mediastinum to the top of the sternum, with focus on preserving the right gastroepiploic vein and gastric-tube wall. Subsequently, laparoscopic surgery was performed to remove the gastric tube from the thoracoabdominal junction. After separating the esophagus on the oral side of the torsion from the left cervical wound, the abdomen was opened, the gastric tube was pulled out through the abdominal wound, and adhesions in the abdominal cavity were peeled off to raise the gastric tube cranially via the retrosternal route. An end-to-side anastomosis was performed using a circular stapler, and the esophageal torsion and previous anastomosis were resected. Oral intake was resumed on the 7th postoperative day, and the patient was discharged on the 38th day. CONCLUSIONS: After subtotal esophagectomy and retrosternal gastric tube reconstruction, the left thoracoscopic approach is one of the most minimally invasive approaches and is especially useful for preserving the right gastroepiploic artery and veins and for mobilizing the gastric tube wall.

[Treatment Strategies for Liver Oligometastases of Esophageal Cancer].

Benefits of local therapy for liver oligometastases of esophageal cancer has not been established. There are 2 cases of resection for liver oligometastases of esophageal cancer. Case 1: A 65-year-old male diagnosed with liver metastasis of esophageal cancer 12 months after initial treatment. A tumor located in segment 7 was resected after 6 months of chemotherapy. Case 2: A 71-year-old female diagnosed with liver metastasis of esophageal cancer 14 months after initial treatment. During 6 months of chemotherapy, tumor diameter increased but there were no new lesions. The tumor located in segment 8 was resected. In both cases, R0 resection was performed without intraoperative injury to the reconstructed esophagus. They had a recurrence free survival of more than 5 months. Resection of liver metastasis of esophageal cancer may be useful in combination with drug therapy in case it was diagnosed with liver oligometastases.

Thoracic esophageal injury due to a neck stab wound: a case report.

BACKGROUND: Traumatic esophageal injury leads to severe complications such as mediastinitis, pyothorax, and tracheoesophageal fistula. Although prompt diagnosis and treatment are required, there are no established protocols to guide diagnosis or treatment. In particular, thoracic esophageal injury tends to be diagnosed later than cervical esophageal injury because it has few specific symptoms. We report a case of thoracic esophageal injury caused by a cervical stab wound; the patient was stabbed with a sharp blade. CASE PRESENTATION: A 74-year-old woman was attacked with a knife while sleeping at home. The patient was taken to the emergency room with an injury localized to the left section of her neck. She was suspected of a left jugular vein and recurrent laryngeal nerve injury from cervical hematoma and hoarseness. On the day following the injury, computed tomography revealed a thoracic esophageal injury. Emergency surgery was performed for an esophageal perforation and mediastinal abscesses. Although delayed diagnosis resulted in suture failure, the patient was able to resume oral intake of food a month later following enteral feeding with a gastrostomy. Esophageal injuries due to sharp trauma are rare, and most are cervical esophageal injuries. There are very few reports on thoracic esophageal injuries. CONCLUSIONS: The possibility of thoracic esophageal injury should always be considered when dealing with neck stab wounds, particularly those caused by an attack.

[A Case of Advanced Esophagogastric Junction Cancer Responding to Combined Modality Therapy].

The patient was a 75-year-old man with advanced esophagogastric junction cancer.He received 2 courses of neoadjuvant chemotherapy with DCS followed by lower esophagectomy and total gastrectomy via the left thoracoabdominal approach. Pathological examination revealed EGJ adenocarcinoma(pT3N4M0, pStage Ⅳa).He was followed up after the surgery and was diagnosed with pulmonary portal lymph node and No.1 07 node recurrences 4 years and 8 months after the surgery, respectively.He received 2 courses of TS-1 monotherapy and chemoradiotherapy, resulting in a complete response(CR).He has remained in CR until June 2019.

[Surgical Treatment for Synchronous Double Cancer of the Thoracic Esophagus and Lung].

We herein report 2 cases of radical operation for synchronous double cancer of the thoracic esophagus and each side of the lung. Case 1:A 71-year-old woman with synchronous double cancer of the thoracic esophagus (Mt, T3N2M0, Stage III) and right lung (M, T2aN0M0, Stage I B) underwent esophagectomy concomitantly with right middle lobectomy through right thoracotomy (single-stage operation) after 2 courses of systemic chemotherapy with docetaxel, cisplatin and 5-fluorouracil( DCF regimen). Case 2:A 72-year-old man with synchronous double cancer of the thoracic esophagus( MtLt, T3N2M0, Stage III) and left lung( U, T1aN0M0, Stage I A) underwent 2-stage operation after 2 courses of the DCF therapy. Esophagectomy through right thoracotomy was performed followed by left upper lobectomy through left thoracotomy 3 months later. Treatment strategy for synchronous double cancer of the thoracic esophagus and lung is discussed based on our experiences and previous reports.

Transcatheter arterial embolization for intercostal arterio-esophageal fistula in esophageal cancer.

BACKGROUND: While esophageal fistula formation in the adjacent organs is associated with high rates of morbidity and mortality, the management of non-aortic arterio-esophageal fistula has not been frequently reported. CASE PRESENTATION: A 69-year-old Japanese man who had undergone definitive chemoradiotherapy for esophageal cancer was admitted to our hospital with hematemesis. He was diagnosed with mediastinal abscess caused by esophageal perforation, and esophageal bypass surgery was performed. After 3 days, he presented with fatal hemoptysis. As angiography revealed an intercostal artery pseudoaneurysm, transcatheter arterial embolization was performed. CONCLUSIONS: When patients with esophageal cancer, especially those with a history of radiotherapy and/or mediastinitis, present with hematemesis and/or hemoptysis, the possibility of non-aortic arterio-esophageal fistula should be considered. Transcatheter arterial embolization is an effective treatment for non-aortic arterio-esophageal fistula.

[Long-Term Survivor of a Barrett's Esophageal Adenocarcinoma, Who Underwent Three Times Surgical Resection and MultidisciplinaryTherapyfor Lymph Node Recurrences - Report of a Case].

We report a case of a 42-year-old man who underwent 3 times surgical resection for lymph nodes recurrence and multidisciplinary therapy for Stage IV b Barrett's esophageal adenocarcinoma, and was well 6 years and 3 months after the first resection. The prognosis of the recurrence cases after radical recection of the esophageal cancer is extremely poor. Long-term prognosis may be obtained in few patients, but the cases are squamous cell carcinoma in most of the reported cases. The number of Barrett's esophageal adenocarcinoma patients is increasing, but it is not many. There is little reports, and there is no fixed treatment policy.

[A Patient with Stage IV Gastric Cancer Who Survived More Than Five Years after Gastrectomy].

The prognosis of patients with Stage IV gastric cancer is generally poor. The 5-year overall survival rate is less than 10%. The patient was a 73-year-old man with Stage IV gastric cancer. Before chemotherapy, peritoneal dissemination was observed using staging laparoscopy. The patient received first-line chemotherapy with TS-1 plus CDDP. Renal function worsened and consequently the therapy was stopped. He received 3 courses of chemotherapy with weekly PTX. The peritoneal dissemination had disappeared by the second staging laparoscopy and he underwent distal gastrectomy. The final diagnosis was pT4a, ly2, v1, pN2(4/16),M0, fStage III B. The patient received adjuvant chemotherapy of TS-1 for 4 years and 8months after gastrectomy. More than 5 year after gastrectomy, the patient is alive without recurrence.

Spleen preservation versus splenectomy in laparoscopic total gastrectomy with D2 lymphadenectomy for gastric cancer: A comparison of short-term outcomes.

INTRODUCTION: Splenic hilar lymph node dissection via a splenectomy for advanced proximal gastric cancer remains controversial. Recently, a laparoscopic spleen-preserving hilar lymph node dissection procedure was described in several publications. To assess the feasibility and safety of spleen-preserving laparoscopic total gastrectomy with D2 lymphadenectomy (LTG-D2), the present retrospective study compared the short-term surgical outcomes between spleen preservation and splenectomy during laparoscopic D2 total gastrectomy (LTG-D2S). METHOD: This study included 59 patients who underwent LTG-D2 and 19 patients who underwent LTG-D2S. RESULTS: The mean operation time did not significantly differ between the LTG-D2 and LTG-D2S groups (339.4 ± 56.8 vs 356.8 ± 46.0 min). The mean blood loss tended to be smaller in the LTG-D2 group than in the LTG-D2S group (105.9 ± 89.7 vs 210.0 ± 149.5 mL). The mean number of retrieved lymph nodes did not significantly differ between the LTG-D2 and LTG-D2S groups (39.9 ± 17.0 vs 40.6 ± 14.9), and the mean number of retrieved lymph nodes at the splenic hilum also did not significantly differ between the LTG-D2 and LTG-D2S groups (1.3 ± 1.7 vs 2.4 ± 2.6). Mild pancreatic fistula occurred in three cases (5%) in the LTG-D2 group and in three cases (15.8%) in the LTG-D2S group. CONCLUSION: A LTG-D2 is feasible in terms of the short-term outcomes. However, the indications for this complicated procedure should be considered carefully.

Triple-incision laparoscopic distal gastrectomy for the resection of gastric cancer: comparison with conventional laparoscopy-assisted distal gastrectomy.

INTRODUCTION: Reduced port surgery and single-port surgery are currently in the spotlight as next-generation, minimally invasive surgical techniques. We performed a triple-incision laparoscopic distal gastrectomy (TIL-DG) for gastric cancer as a reduced port surgery. METHOD: A total of 76 patients underwent a TIL-DG. A D1+ or D2 lymph node dissection was performed, and the Roux-en-Y method was used for reconstruction. The short-term patient outcomes of the TIL-DG group were compared with those of the conventional laparoscopy-assisted distal gastrectomy group (59 cases) to evaluate the feasibility of TIL-DG. RESULTS: No significant differences were observed between the TIL-DG group and the laparoscopy-assisted distal gastrectomy group in terms of mean operative time, blood loss, and the length of the postoperative hospital stay. The mean number of retrieved regional lymph nodes in the TIL-DG group was slightly higher than that in the laparoscopy-assisted distal gastrectomy group. CONCLUSION: A triple-incision laparoscopic distal gastrectomy is a feasible and safe procedure.

[A case of advanced esophagogastric junction cancer responding to pre-operative combination chemotherapy of docetaxel, cisplatin, S-1, and trastuzumab].

We have no consensus on surgical treatment and chemotherapy for esophagogastric junction cancer in Japan. A 51-yearold man reporting dysphagia was examined, and through upper gastrointestinal endoscopy was found to have a tumor at the esophagogastric junction. Histologically, biopsy specimens indicated adenocarcinoma with genetic amplification of human epidermal growth factor receptor type 2(HER2). Positron emission tomography showed swelling of several abdominal lymph nodes with accumulation of fluorodeoxyglucose. He was treated with esophagogastorectomy with left thoracotomy after combination chemotherapy of docetaxel, cisplatin, S-1, and trastuzumab. He had no complication from the operation and had no adverse effect from the combination chemotherapy. Histopathological examination of the resected specimen showed a minute residual cancer nest at the muscularis propria of the esophagus, but no lymph node metastasis. This regimen could be useful for advanced junctional cancer with HER2 amplification as preoperative chemotherapy.

[A case of multiple distant lymph node metastases from advanced gastric cancer treated with adjuvant chemotherapy after total gastrectomy].

A 70-year-old woman with advanced gastric cancer (U, type 3, por, pT3, ly3, v2, pN3a [10/92, No. 1, 3], Stage IIIB) underwent total gastrectomy and D2 dissection followed by adjuvant chemotherapy with S-1. Eight months later, computed tomography (CT) showed multiple distant lymph node metastases, including metastases in the para-aortic and supraclavicular( Virchow's nodes) lymph nodes. Chemotherapy with cisplatin( CDDP) and irinotecan( CPT-11) was administered with concurrent radiation therapy for the para-aortic nodes. After 2 courses, the para-aortic lymph nodes showed complete response( CR), but Virchow's nodes showed partial response( PR). Dissection of Virchow's nodes was performed. Histopathological examination revealed a chemotherapeutic effect on the dissected node, and therefore, 2 more courses of chemotherapy were administered after the operation. Adverse events such as grade 3 neutropenia and grade 4 hyponatremia were observed. At present, the patient is well without recurrence, and chemotherapy is not being administered. Local therapy for distant metastasis followed by systemic chemotherapy may have been effective in this case.