Robot-assisted transcervical esophagectomy with a bilateral cervical approach for thoracic esophagectomy.

BACKGROUND: Thoracic esophageal cancer resection through the neck approach has recently been reported as mediastinoscopic surgery. We present the first report of a new minimally invasive technique for thoracic esophageal cancer: robot-assisted transcervical esophagectomy with a bilateral cervical approach. METHODS: Ten cases of robot-assisted bilateral transcervical esophagectomy performed at the National Cancer Center Hospital East, Japan, from February 2023 to August 2023 were reviewed. The short-term surgical outcomes were presented, and the feasibility and efficacy of this procedure were discussed. RESULTS: The mean operation time for the cervical procedure was 184.2 ± 23.6 min. The total time for the whole procedure was 472.7 ± 28.4 min, and total intraoperative blood loss was 162.2 ± 40.0 ml. Among the 10 cases, one patient developed recurrent nerve paralysis, one patient developed pulmonary complications, and no patients developed postoperative pneumonia. The median postoperative hospital stay was 22 (range: 12-43) days. No patients developed severe postoperative surgical complications, which were graded as Clavien-Dindo ≥ III. The total number of surgically harvested mediastinal lymph nodes was 37.2 ± 11.2. CONCLUSIONS: Robot-assisted bilateral transcervical esophagectomy, a novel procedure for thoracic esophageal cancer, was safe and feasible. Using this procedure, the incidence of recurrent nerve palsy, which is a problem with transcervical esophagectomy and mediastinoscopic esophagectomy, is expected to decrease.

Total RAMIE with three-field lymph node dissection by a simultaneous two-team approach using a new docking method for esophageal cancer.

BACKGROUND: Thoracic esophageal cancer surgery using robotic approaches for the thoracic and abdominal parts has recently been reported as total robot-assisted minimally invasive esophagectomy (RAMIE). We herein present the first report of a new technique for esophageal cancer: total RAMIE with three-field lymph node dissection (3FLND) by a simultaneous two-team approach using a new docking method. METHODS: We reviewed 20 patients who underwent total RAMIE with 3FLND by a simultaneous two-team approach at the National Cancer Center East Hospital from March 2023 to September 2023. Short-term surgical outcomes and the safety and efficacy of this technique were analyzed. RESULTS: The mean operative time for abdominal surgery with this new docking technique was 135 ± 19.6 min. The total operative time was 488 ± 42.9 min, and the time from the end of abdominal manipulation to the end of surgery was 80.1 ± 15.6 min. The intraoperative blood loss was 116.7 ± 64.4 mL. The incidence of anastomotic leakage, postoperative vocal cord paralysis, and postoperative pneumonia was 10%, 5%, and 10%, respectively. The median postoperative hospital stay was 14 days (range 11-63 days). No in-hospital deaths occurred, and R0 resection was possible in all cases. The average number of lymph nodes dissected was 87.7. CONCLUSION: These results demonstrate that total RAMIE with a simultaneous two-team approach using the new docking method can be safely introduced. The simultaneous cervical and abdominal manipulation with the new docking method allowed total RAMIE without prolonging the operating time, suggesting that it may be a valuable approach for esophageal cancer surgery.

Efficiency of conversion surgery for esophageal squamous cell carcinoma with solitary abdominal para-aortic lymph node metastasis.

PURPOSE: Abdominal para-aortic lymph nodes (PANs) are sites of distant metastasis in esophageal squamous cell cancer (ESCC). The prognosis of patients with Stage IVB ESCC and abdominal PAN metastasis is extremely poor. However, chemotherapy for ESCC has recently been developed, and the effectiveness of combined induction therapy and conversion surgery remains unclear. The primary objective of this study was to evaluate the short- and long-term outcomes of conversion surgery for ESCC and solitary abdominal PAN metastases after induction therapy. METHODS: Thirteen patients who underwent conversion esophagectomy for cStage IVB ESCC with solitary abdominal PAN metastasis after induction therapy between January 2017 and October 2022 at our institution were enrolled. The short- and long-term outcomes of conversion surgery were retrospectively evaluated. RESULTS: Three patients (23.1%) had pathological abdominal PAN metastasis, and six patients (46.2%) without pathological abdominal PAN metastasis showed that chemotherapy eliminated the tumors in the abdominal PAN. Three patients (23.1%) had postoperative complications of Clavien-Dindo grade II or higher. The 3-year overall and recurrence-free survival rates were 83.1% and 51.3%, respectively. CONCLUSIONS: Our findings showed that conversion surgery for ESCC and solitary abdominal PAN metastasis led to a good prognosis when induction therapy was successful.

A novel device to assess the oxygen saturation and congestion status of the gastric conduit in thoracic esophagectomy.

BACKGROUND: In thoracic esophagectomy, anastomotic leakage is one of the most important surgical complications. Indocyanine green (ICG) is the most widely used method to assess tissue blood flow; however, this technique has been pointed out to have disadvantages such as difficulty in evaluating the degree of congestion, lack of objectivity in evaluating the degree of staining, and bias easily caused by ICG injection, camera distance, and other factors. Evaluating tissue oxygen saturation (StO2) overcomes these disadvantages and can be performed easily and repeatedly. It is also possible to measure objective values including the degree of congestion. We evaluate novel imaging technology to assess tissue oxygen saturation (StO2) in the gastric conduit during thoracic esophagectomy. METHODS: Fifty patients were enrolled, with seven excluded due to intraoperative findings, leaving 43 for analysis. These patients underwent thoracic esophagectomy for esophageal cancer. The device was used intraoperatively to evaluate tissue oxygen saturation (StO2) and total hemoglobin index (T-HbI), which guided the optimal site for gastric tube anastomosis. The efficacies of StO2 and T-HbI in relation to short-term outcomes were analyzed. RESULTS: StO2, indicating blood supply to the gastric tube, remained stable beyond the right gastroepiploic artery (RGEA) end but significantly decreased distally to the demarcation line (p <  0.05). T-HbI, indicative of congestion, significantly decreased past the RGEA (p <  0.05). Three patients experienced anastomotic leakage. These patients exhibited significantly lower StO2 (p <  0.01) and higher T-HbI (p <  0.01) at both the RGEA end and the demarcation line. Furthermore, the anastomotic site, usually within 3 cm of the RGEA's anorectal side, also showed significantly lower StO2 (p <  0.01) and higher T-HbI (p <  0.01) in patients with anastomotic leakage. CONCLUSIONS: The novel device provides real-time, objective evaluations of blood flow and congestion in the gastric tube. It proves useful for safer reconstruction during thoracic esophagectomy, particularly by identifying optimal anastomosis sites and predicting potential anastomotic leakage.

[Management of Postoperative Infectious Complications After Thoracic Esophagectomy].

Although minimally invasive procedures such as thoracoscopic surgery and robot-assisted surgery have become increasingly popular in esophageal cancer in recent years, perioperative management remains a very important topic. However, perioperative management is still an extremely important issue, as esophagectomy is still a highly invasive procedure. Especially in recent years, as the patient population ages, it is expected that we will have more and more opportunities to deal with patients with various pre-existing medical conditions in addition to the original decline in physical function. In this article, we discuss the management of infectious complications in the perioperative management of esophageal surgery, with a particular focus on esophagectomy and reconstruction.

The feasibility of post-photodynamic therapy salvage esophagectomy in patients with esophageal squamous cell carcinoma treated with definitive chemoradiotherapy.

BACKGROUND: Photodynamic therapy (PDT) is a minimally invasive salvage treatment for local residual or recurrent lesions that persist after the definitive chemoradiotherapy (dCRT) of esophageal cancer. However, esophageal cancer persistence after PDT is associated with a poor prognosis. Although esophagectomy is a curative treatment option, few studies have evaluated its efficacy. Thus, this study aimed to evaluate the outcomes of salvage esophagectomy after PDT. METHODS: 14 patients who underwent salvage esophagectomy for residual or recurrent esophageal cancer after PDT between April 2006 and November 2022 at our institution, were enrolled. The short-term (e.g., blood loss, operative time, R0 rate, postoperative complications, and postoperative hospital stay) and long-term (e.g., overall survival [OS] and recurrence-free survival [RFS]) of salvage esophagectomy after PDT were evaluated retrospectively. RESULTS: The median operative time and intraoperative blood loss were 355 min and 350 ml, respectively. Eight patients (57.1%) had postoperative complications of Clavien-Dindo grade II or more. The median postoperative hospital stay was 20.5 days. The 3-year OS and RFS rates were 23.5% (95% confidence interval [CI] 5.7-48.0) and 16.3% (95% CI 2.7-40.3), respectively. Seven patients with an R0 had significantly longer OS than the seven patients with R1 and 2 (p = 0.045). The 3-year OS rate for patients with R0 was 52.6%. CONCLUSIONS: Although salvage esophagectomy after PDT carries certain risks, patients who achieved an R0 had a promising long-term prognosis. The location and size of the lesion may be critical factors in determining whether R0 can be achieved with salvage esophagectomy after PDT.

Impact of pre-diabetes, well-controlled diabetes, and poorly controlled diabetes on anastomotic leakage after esophagectomy for esophageal cancer: a two-center retrospective cohort study of 1901 patients.

BACKGROUND: Diabetes is known to be associated with anastomotic leakage (AL) after esophagectomy. However, it is unknown whether well-controlled diabetes is also associated with AL. METHODS: We conducted a two-center retrospective cohort database study of patients who underwent oncological esophagectomy (2011-2019). Patients were divided into four groups: normoglycemia, pre-diabetes, well-controlled diabetes (hemoglobin A1c [HbA1c] < 7.0%), and poorly controlled diabetes (HbA1c ≥ 7.0%). The occurrence of AL and length of stay were compared between groups using multivariable analyses. The relationship between categorical HbA1c levels and AL was also investigated in patients stratified by diabetes medication before admission. RESULTS: Among 1901 patients, 1114 (58.6%) had normoglycemia, 480 (25.2%) had pre-diabetes, 180 (9.5%) had well-controlled diabetes, and 127 (6.7%) had poorly controlled diabetes. AL occurred in 279 (14.7%) patients. Compared with normoglycemia, AL was significantly associated with both well-controlled diabetes (odds ratio 1.83, 95% confidence interval [CI] 1.22-2.74) and poorly controlled diabetes (odds ratio 1.95, 95% CI 1.23-3.09), but not with pre-diabetes. Preoperative HbA1c levels showed a J-shaped association with AL in patients without diabetes medication, but no association in patients with diabetes medication. Compared with normoglycemia, only poorly controlled diabetes was significantly associated with longer hospital stay after surgery, especially in patients with operative morbidity (unstandardized coefficient 14.9 days, 95% CI 5.6-24.1). CONCLUSIONS: Diabetes was associated with AL after esophagectomy even in well-controlled patients, but pre-diabetes was not associated with AL. Operative morbidity, including AL, in poorly controlled diabetes resulted in prolonged hospital stays compared with normoglycemia.

Real-time detection of the recurrent laryngeal nerve in thoracoscopic esophagectomy using artificial intelligence.

BACKGROUND: Artificial intelligence (AI) has been largely investigated in the field of surgery, particularly in quality assurance. However, AI-guided navigation during surgery has not yet been put into practice because a sufficient level of performance has not been reached. We aimed to develop deep learning-based AI image processing software to identify the location of the recurrent laryngeal nerve during thoracoscopic esophagectomy and determine whether the incidence of recurrent laryngeal nerve paralysis is reduced using this software. METHODS: More than 3000 images extracted from 20 thoracoscopic esophagectomy videos and 40 images extracted from 8 thoracoscopic esophagectomy videos were annotated for identification of the recurrent laryngeal nerve. The Dice coefficient was used to assess the detection performance of the model and that of surgeons (specialized esophageal surgeons and certified general gastrointestinal surgeons). The performance was compared using a test set. RESULTS: The average Dice coefficient of the AI model was 0.58. This was not significantly different from the Dice coefficient of the group of specialized esophageal surgeons (P = 0.26); however, it was significantly higher than that of the group of certified general gastrointestinal surgeons (P = 0.019). CONCLUSIONS: Our software's performance in identification of the recurrent laryngeal nerve was superior to that of general surgeons and almost reached that of specialized surgeons. Our software provides real-time identification and will be useful for thoracoscopic esophagectomy after further developments.

A novel imaging technology to assess oxygen saturation of the gastric conduit in thoracic esophagectomy.

BACKGROUND: Real-time evaluation of blood perfusion is important when selecting the site of anastomosis during thoracic esophagectomy. This study investigated a novel imaging technology that assesses tissue oxygen saturation (StO2) in the gastric conduit and examined its efficacy. METHODS: Fifty-one patients undergoing thoracic esophagectomy for esophageal cancer who underwent intraoperative StO2 endoscopic imaging to assess the gastric conduit for the optimal site of anastomosis were examined. Efficacy of oxygen saturation imaging and patient outcomes were analyzed. RESULTS: All 51 patients underwent esophagectomy without intraoperative problems. Mean StO2 in the gastric tube was highest at the pre-pylorus area and then gradually decreased proceeding toward the tip. StO2 was well preserved in areas supplied by the right gastroepiploic artery but low in other areas. Anastomotic sites were selected based on StO2 imaging and tension considerations; most were located within 3 cm of the end of the right gastroepiploic artery. Three patients developed postoperative anastomotic leakage (5.8%). Mean StO2 at the point of anastomosis was significantly lower in the patients who experienced leakage than in those who did not (P = 0.04). CONCLUSION: Intraoperative endoscopic StO2 imaging is useful in esophageal cancer patients undergoing thoracic esophagectomy to determine the optimal site for anastomosis to minimize the risk of anastomotic leakage.

Propensity-Matched Analysis of the Short-Term Outcome of Robot-Assisted Minimally Invasive Esophagectomy Versus Conventional Thoracoscopic Esophagectomy in Thoracic Esophageal Cancer.

BACKGROUND: In this matched-cohort study, we investigated the short-term outcome of robot-assisted minimally invasive esophagectomy (RAMIE) compared with conventional minimally invasive thoracoscopic esophagectomy (MIE) in esophageal cancer patients. METHODS: One hundred eighty-nine patients with thoracic esophageal cancer scheduled to undergo thoracic esophagectomy between 2020 and 2021 were assigned to either RAMIE or MIE. Then, we retrospectively evaluated the postoperative surgical complications between two groups in a propensity-matched analyzation. RESULTS: Based on the propensity-matched score, 50 patients who underwent RAMIE or MIE were selected. Thoracic surgery time in RAMIE/MIE group were 233.1/173.3 min (p < 0.01), respectively. No significant intergroup differences were observed regarding incisional anastomotic leakage (RAMIE group 4.0% vs. MIE group 6.0%) and pneumonia (RAMIE group 8.0% vs. MIE group 12.0%; p = 0.68). The respective incidences of recurrent laryngeal nerve paralysis were 34.0 and 8.0% in the MIE and RAMIE groups, respectively (p < 0.01). In the matched cohort, no differences were observed between the groups in the success accomplishment of the clinical management pathway (RAMIE group 94.0% vs. MIE group 88.0%). CONCLUSIONS: Although patients who underwent RAMIE had longer operation times, the incidence of recurrent laryngeal nerve paralysis was lower than with MIE. Further study in a prospective multi-institutional setting are required to confirm the superiority of RAMIE compared with MIE.

Propensity-matched analysis of the efficacy of olanexidine gluconate versus chlorhexidine-alcohol as an antiseptic agent in thoracic esophagectomy.

BACKGROUND: In the present matched-cohort study, we investigated the efficacy of olanexidine gluconate in comparison with chlorhexidine-alcohol as an antiseptic agent in thoracic esophagectomy. METHODS: A total of 372 patients with esophageal cancer who were scheduled to undergo thoracic esophagectomy between 2016 and 2018 were assigned to one of two groups based on the preoperative antiseptic agent used in thoracic esophagectomy. We investigated the incidence of surgical site infectious complications in the propensity-matched cohort. RESULTS: Based on the propensity score, 116 patients prepared with 1.5% olanexidine gluconate and 114 patients prepared with 1.0% chlorhexidine-alcohol as surgical skin antisepsis were selected. No significant intergroup differences were observed with respect to incisional surgical site infection (0.8% in the olanexidine group versus 0.8% in the chlorhexidine group) and deep fascial/organ space surgical site infection (1.7%/10.3% in the olanexidine group versus 3.5%/15.7% in the chlorhexidine group, p = 0.39/p = 0.03). Notably, the respective incidences of surgical site infection except anastomotic leakage were 1.7% and 7.0% in the olanexidine and chlorhexidine groups (p = 0.04). CONCLUSIONS: Olanexidine gluconate was well tolerated and significantly reduced incidence of surgical site infection except anastomotic leakage in comparison with chlorhexidine-alcohol as an antiseptic agent in thoracic esophagectomy with three-field lymph node dissection.

Novel universally applicable technique for performing bilateral transcervical mediastinoscopic-assisted transhiatal laparoscopic esophagectomy: a truly minimally invasive procedure.

BACKGROUND: The procedure of mediastinoscopic-assisted transhiatal esophagectomy (MATE) is only performed in a few institutions, despite this being the ultimate form of minimally invasive surgery for performing esophagectomy for esophageal and esophagogastric cancer in that it entails no chest wall trauma. We have developed a novel, universally applicable, surgical procedure for performing bilateral transcervical mediastinoscopic-assisted transhiatal laparoscopic esophagectomy (BTC-MATLE) that is an improvement on standard MATE surgery for esophageal and esophagogastric cancer. METHODS: The patient is placed in a supine position under general anesthesia with bilateral lung ventilation. BTC-MATLE combined with mediastinoscopic and transhiatal laparoscopic esophagectomy with total mediastinal lymph node dissection are performed synchronously. After lymph node dissection along both recurrent laryngeal nerves through bilateral cervical skin incisions, bilateral transcervical mediastinoscopic esophagectomy is performed to avoid collision outside the cervical region and ensure operability even in patients with narrow mediastimun. Laparoscopic gastric mobilization and subsequent lower esophageal mobilization meet the bilateral transcervical mediastinoscopic esophagectomy at the border of the middle and lower third of the esophagus. The gastric tube is pulled up into the cervical region via a posterior mediastinal route and anastomosed in the neck. RESULTS: BTC-MATLE was performed on 16 high-risk patients (Charlson Comorbidity Index ≥ 3 in 14 patients and two octogenarians with complex comorbidities). Median operation time and postoperative hospital stay were 231 min and 15 days, respectively. R0 resection was achieved in 15 patients (94%), and there were no in-hospital deaths. CONCLUSIONS: BTC-MATLE, a procedure for performing minimally invasive esophagectomy, is likely to become the applicable form of MATE surgery for esophageal and esophagogastric cancer, even in high-risk patients because it is truly minimally invasive and has excellent short-term outcomes.

Robotic esophagectomy with total mediastinal lymphadenectomy using four robotic arms alone in esophageal and esophagogastric cancer (RETML-4): a prospective feasibility study.

BACKGROUND: Robotic-assisted esophagectomy is still in the implementation phase. Robotic surgical systems refine visualization via robotically-enhanced surgical anatomy (RESA), and the stable articulated robotic arms provide precise movements. This prospective feasibility study was conducted to evaluate robotic esophagectomy with total mediastinal lymphadenectomy using four robotic arms exclusively (RETML-4). METHODS: The inclusion criterion was clinical stage I-IIIB esophageal cancer with stable general condition. Patients were positioned hemi-prone with single-lung ventilation, and the operation table was tilted until the patient was prone. The first, second, third, and fourth robotic ports were inserted into the ninth intercostal space (ICS) on the angulus inferior scapulae line, seventh ICS on the posterior axillary line, and the fifth and third ICS on the mid-axillary line, respectively. RETML-4 was performed by precise sharp dissection in wide stable operation fields, with countertraction created by a tip-up fenestrated grasper with gauze. Esophagectomy was performed separately for the middle to lower, and upper esophagus. After mobilizing the middle to lower esophagus and performing lymph node dissection, the upper esophagus was mobilized, with bilateral lymph node dissection along the recurrent laryngeal nerves. The assistant surgeon was involved only during removing gauze and collecting harvested lymph nodes in the thorax. RESULTS: RETML-4 was performed in all ten patients enrolled in 2018. The median postoperative hospital stay was 15 days, and the complication rate was 60%. Nine cases achieved R0 resection. Recurrence occurred in two cases. CONCLUSIONS: RETML-4 is feasible, and may facilitate minimally invasive esophagectomy by providing precise instrument movements and RESA.

Novel minimally invasive approach to lymph node dissection around the left renal vein in patients with esophagogastric junction cancer.

The left renal vein lymph node (LRVLN) may be the extended locoregional node in esophagogastric junction cancer; however, only open-surgical methods of dissection have been reported. We therefore developed a novel minimally invasive laparoscopic method for LRVLN dissection. Following esophagectomy, the stomach was mobilized and LRVLN dissection was started by taping the pancreatic body using two silicone drains. The transverse mesocolon was then retracted through the superior duodenal fossa to expose the horizontal duodenum and permit LRVLN dissection. We carried out the procedure successfully in 17 patients with advanced esophagogastric cancer. The median total and laparoscopic operative times were 415 and 161 min, respectively. Postoperative esophagectomy-related complications occurred in six patients. The median estimated blood loss was 120 ml and hospital stay was 15 days. This minimally invasive laparoscopic LRVLN dissection method was safe and effective, and may support faster recovery and earlier postoperative adjuvant therapy in patients with esophagogastric junction cancer.

Totally Mechanical Collard Technique for Cervical Esophagogastric Anastomosis Reduces Stricture Formation Compared with Circular Stapled Anastomosis.

BACKGROUND: The optimal technique for cervical esophagogastric anastomosis in esophagectomy has not yet been established. Using circular stapled (CS) technique effectively reduces the incidence of anastomotic leakage and shortens the operating time; however, anastomotic stricture has been reported to be more common. The present study was performed to compare the clinical outcomes of the recently developed totally mechanical Collard (TMC) and CS anastomosis. METHODS: We retrospectively reviewed consecutive esophageal cancer cases who are undergoing transthoracic extended esophagectomy with gastric conduit reconstruction using cervical CS or TMC anastomosis from December 2013 to December 2016. Propensity score matching and multivariate regression were used to adjust for differences in baseline characteristics. RESULTS: Among 313 patients, 93 underwent CS anastomosis and 220 underwent TMC anastomosis. Stricture formation occurred in 59 patients (18.8%), significantly more often with the CS than TMC anastomosis (30.1% vs. 14.1%, p = 0.001). No significant differences were observed in the refractory stricture rate (9.7% vs. 5.0%, p = 0.134) or the anastomotic leakage rate (11.8% vs. 10.9%, p = 0.845) between the two groups. The propensity score matching cohort study including 86 pairs of patients confirmed a significantly lower stricture formation rate with the TMC than CS technique (27.9% vs. 14.0%, p = 0.038). In the multivariable analysis, anastomotic leakage, the CS technique, and a body mass index of ≥25 mg/m2 were independently associated with a risk of stricture formation. CONCLUSION: TMC technique contributed to a reduced rate of stricture formation compared with CS technique in cervical esophagogastric anastomosis.

From photoelectron detachment spectra of BrHBr(-), BrDBr(-) and IHI(-), IDI(-) to vibrational bonding of BrMuBr and IMuI.

Photoelectron detachment XLX(-)(00(0)0) + hν → XLX(vib) + e(-) + KER (X = Br or I, L = H or D) at sufficiently low temperatures photoionizes linear dihalogen anions XLX(-) in the vibrational ground state (v1v2 (l)v3 = 00(0)0) and prepares the neutral radicals XLX(vib) in vibrational states (vib). At the same time, part of the photon energy (hν) is converted into kinetic energy release (KER) of the electron [R. B. Metz, S. E. Bradforth, and D. M. Neumark, Adv. Chem. Phys. 81, 1 (1992)]. The process may be described approximately in terms of a Franck-Condon type transfer of the vibrational wavefunction representing XLX(-)(00(0)0) from the domain close to the minimum of its potential energy surface (PES) to the domain close to the linear transition state of the PES of the neutral XLX. As a consequence, prominent peaks of the photoelectron detachment spectra (pds) correlate with the vibrational energies EXLX,vib of states XLX(vib) which are centered at linear transition state. The corresponding vibrational quantum numbers may be labeled vib = (v1v2 (l)v3) = (00(0)v3). Accordingly, the related most prominent peaks in the pds are labeled v3. We construct a model PES which mimics the "true" PES in the domain of transition state such that it supports vibrational states with energies EXLX,pds,00(0)v3 close to the peaks of the pds labeled v3 = 0, 2, and 4. Subsequently, the same model PES is also used to calculate approximate values of the energies EXMuX,00(0)0 of the isotopomers XMuX(00(0)0). For the heavy isotopomers XHX and XDX, it turns out that all energies EXLX,00(0)v3 are above the threshold for dissociation, which means that all heavy XLX(00(0)v3) with wavefunctions centered at the transition state are unstable resonances with finite lifetimes. Turning the table, bound states of the heavy XLX are van der Waals (vdW) bonded. In contrast, the energies EXMuX,00(0)0 of the light isotopomers XMuX(00(0)0) are below the threshold for dissociation, with wavefunctions centered at the transition state. This means that XMuX(00(0)0) are vibrationally bonded. This implies a fundamental change of the nature of chemical bonding, from vdW bonding of the heavy XHX, XDX to vibrational bonding of XMuX. For BrMuBr, the present results derived from experimental pds of BrHBr(-) and BrDBr(-) confirm the recent discovery of vibrational bonding based on quantum chemical ab initio calculations [D. G. Fleming, J. Manz, K. Sato, and T. Takayanagi, Angew. Chem., Int. Ed. 53, 13706 (2014)]. The extension from BrLBr to ILI means the discovery of a new example of vibrational bonding. These empirical results for the vibrational bonding of IMuI, derived from the photoelectron spectra of IHI(-) and IDI(-), are supported by ab initio simulations of the spectra and of the wavefunction representing vibrational bonding of IMuI.

Fundamental change in the nature of chemical bonding by isotopic substitution.

Isotope effects are important in the making and breaking of chemical bonds in chemical reactivity. Here we report on a new discovery, that isotopic substitution can fundamentally alter the nature of chemical bonding. This is established by systematic, rigorous quantum chemistry calculations of the isotopomers BrLBr, where L is an isotope of hydrogen. All the heavier isotopomers of BrHBr, BrDBr, BrTBr, and Br(4)HBr, the latter indicating the muonic He atom, the heaviest isotope of H, can only be stabilized as van der Waals bound states. In contrast, the lightest isotopomer, BrMuBr, with Mu the muonium atom, alone exhibits vibrational bonding, in accord with its possible observation in a recent experiment on the Mu+Br2 reaction. Accordingly, BrMuBr is stabilized at the saddle point of the potential energy surface due to a net decrease in vibrational zero point energy that overcompensates the increase in potential energy.

A novel imaging technology to assess tissue oxygen saturation and its correlation with indocyanine green in the gastric conduit during thoracic esophagectomy.

BACKGROUND: Anastomotic leakage in esophagectomy is a serious complication, and assessing blood perfusion in the conduit can help minimize this risk. Indocyanine green is the most widely used method to assess tissue blood flow; however, this technique has disadvantages. Evaluating tissue oxygen saturation in the gastric conduit during thoracic esophagectomy compared with indocyanine green blood perfusion assessment addresses these disadvantages and can be performed easily and repeatedly. METHODS: This was a prospective study of patients with esophageal cancer who underwent thoracic esophagectomy. Intraoperative tissue oxygen saturation and indocyanine green measurements were obtained to determine the anastomotic site and to compare the correlation between the 2 methods. Tissue oxygen saturation and indocyanine green values were obtained at the tip of the gastric conduit, the demarcation line indicating visible perfusion, and the end of the right gastroepiploic artery. RESULTS: Fifty-seven patients were enrolled in this study; 3 developed anastomotic leakage, and all 3 underwent robotic thoracic surgery. The tissue oxygen saturation value decreased gradually toward the tip of the conduit, as did congestion, and was significantly decreased at the tip compared with the value at the demarcation line (P = .001). Mean tissue oxygen saturation differed significantly between the leakage and no-leakage groups at the anastomosis site (P = .04). We found a negative correlation between tissue oxygen saturation and indocyanine green values at the end of the right gastroepiploic artery (r = -0.361; P = .03). CONCLUSION: Tissue oxygen saturation imaging was useful in determining the anastomotic site and addressed the disadvantages associated with indocyanine green.