Supracarinal dissection of the oesophagus and lymphadenectomy by MIE

The number of resected lymph nodes from the upper mediastinal area predicts long-term outcomes of esophageal squamous cell carcinoma after minimally invasive esophagectomy

BACKGROUND

The total number of resected lymph nodes (LNs) is an important determinant of longer survival after esophagectomy for esophageal squamous cell carcinoma (ESCC). However, the resected LN counts from areas that affect long-term outcomes remain unclear.

METHODS

This study included 406 patients who underwent minimally invasive esophagectomies (MIEs) at Kobe University Hospital. Resected LN counts were evaluated in the following areas: upper mediastinal (UM), middle mediastinal (MM), lower mediastinal (LM), and abdominal (Abd). Cut-off values for LN counts from each area were determined using receiver operating characteristics analysis of the survival status. Cox proportional hazards regression analyses were performed to identify prognostic factors.

RESULTS

The cut-off values for large or small numbers of resected LN counts in the UM, MM, LM, and Abd areas were 4, 8, 5, and 18, respectively, in patients with upper and middle thoracic (Ut/Mt) ESCC and 7, 6, 5, and 24, respectively, in patients with lower thoracic (Lt) ESCC. Multivariate analysis in patients with Ut/Mt ESCC revealed that tumor invasion depth, LN metastasis, and the resected LN count from the UM area were independent risk factors for overall survival [hazard ratio (HR), 7.04; 95% confidence interval (CI) 4.47-11.1; HR, 4.01; 95% CI 1.96-8.21; HR, 2.18; 95% CI 1.24-3.82, respectively]. In patients with Lt ESCC, tumor invasion depth, LN metastasis, and pulmonary complications were independent risk factors for overall survival (HR, 4.23; 95% CI 2.14-8.35; HR, 3.83; 95% CI 1.75-8.38; HR, 2.80; 95% CI 1.38-5.65, respectively). Resected LN counts from no areas were prognostic factors.

CONCLUSION

The number of resected LNs from the UM area influenced the survival outcomes of patients with Ut/Mt ESCC after MIE.

Successful management following combined thoracic endovascular aortic repair and minimally invasive esophagectomy for primary aortoesophageal fistula: A case report

Aortoesophageal fistula (AEF) is a rare but life-threatening pathology. We report a case of a primary AEF that was successfully managed with temporary thoracic endovascular aortic repair (TEVAR) and esophagectomy with video-assisted thoracoscopic surgery. A 73-year-old man was transferred to the emergency department with a complaint of hematemesis. A computed tomography scan identified an AEF due to aortic aneurysm. We placed a stent using TEVAR for the purpose of hemodynamic stasis, and the operation was performed 23 h after admission. Right video-assisted thoracoscopic esophagectomy (VATS-E) was chosen, and a cervical esophagostomy and a feeding gastrostomy tube was constructed. Infection had been effectively controlled postoperatively. Four months after the first operation, we performed esophageal reconstruction. At the 70-month follow-up examination, the patient had no signs of mediastinitis. VATS-E immediately after hemostabilization by TEVAR is useful management for primary AEF.

The circRNA circADAMTS6 promotes progression of ESCC and correlates with prognosis

Circular RNAs (circRNAs) are a type of noncoding RNA, which play a vital role in the occurrence and development of esophageal squamous cell carcinoma (ESCC). While the role of novel circADAMTS6 in ESCC remains unknown. We assessed circADAMTS6 expression in ESCC tissues and cells, and the relationship between circADAMTS6 expression and overall survival of ESCC patients. Functional experiments in vitro and xenograft in vivo assay were applied to explore the functions and mechanisms of circADAMTS6 in ESCC. Results found that up-regulation of circADAMTS6 was associated with poor overall survival and may acted as an independent risk factor for ESCC prognosis. Knockdown of circADAMTS6 significantly inhibited the proliferation, migration and invasion of ESCC cells and growth of xenograft tumors in vivo. Induced AGR2 expression was able to rescue the loss of function induced by si-circADAMTS6 in KYSE150 cell. CircADAMTS6 may acts as oncogene by activating AGR2 and the Hippo signaling pathway coactivator YAP in ESCC.

The role of magnetic anchoring and traction technique in thoracoscopic lymphadenectomy along the left recurrent laryngeal nerve

BACKGROUND

Dissecting lymph nodes along the left recurrent laryngeal nerve (LRLN) is the most challenging step in thoracoscopic-assisted esophagectomy. To retract the proximal esophagus in the existing lymphadenectomy methods, either a special trocar is required to insert and take out endoscopic instruments or thoracic punctures are needed to externally retract the esophageal loop. Therefore, advanced skills for esophageal traction are important to facilitate the LRLN lymphadenectomy and to reduce the incidence of trauma to the chest wall. Herein, we present the magnetic anchoring and traction technique, a novel method for LRLN lymphadenectomy during thoracoscopic esophagectomy.

METHODS

The magnetic anchoring traction system was successfully used to retract the upper thoracic esophagus and to help expose the upper mediastinum in 10 cases of thoracoscopic-assisted esophagectomy. When the external magnet was moved outside of body, the internal magnet was coupled with a magnetic force to pull the proximal esophagus to the appropriate direction, which helped to expose the LRLN and adjacent lymph nodes. The lymph nodes adjacent to the LRLN could then be dissected completely without any damage to the nerve.

RESULTS

In all surgeries, the LRLN and adjacent lymph nodes were well visualized, and the number of trocars used to pass endoscopic instruments for retraction of the proximal esophagus or the number of thoracic punctures for external traction of the esophagus during the surgery were reduced.

CONCLUSIONS

In thoracoscopic-assisted esophagectomy, the magnetic anchoring and traction technique can improve the exposure of the LRLN, facilitate LRLN lymphadenectomy, and reduce chest wall trauma.

Surgical anatomy of the upper esophagus related to robot-assisted cervical esophagectomy

Robot-assisted cervical esophagectomy (RACE) enables radical surgery for tumors of the middle and upper esophagus, avoiding a transthoracic approach. However, the cervical access, narrow working space, and complex topographic anatomy make this procedure particularly demanding. Our study offers a stepwise description of appropriate dissection planes and anatomical landmarks to facilitate RACE. Macroscopic dissections were performed on formaldehyde-fixed body donors (three females, three males), according to the surgical steps during RACE. The topographic anatomy and surgically relevant structures related to the cervical access route to the esophagus were described and illustrated, along with the complete mobilization of the cervical and upper thoracic segment. The carotid sheath, intercarotid fascia, and visceral fascia were identified as helpful landmarks, used as optimal dissection planes to approach the cervical esophagus and preserve the structures at risk (trachea, recurrent laryngeal nerves, thoracic duct, sympathetic trunk). While ventral dissection involved detachment of the esophagus from the tracheal cartilage and membranous part, the dorsal dissection plane comprised the prevertebral compartment harboring the thoracic duct and right intercosto-bronchial artery. On the left side, the esophagus was attached to the aortic arch by the aorto-esophageal ligament; on the right side, the esophagus was bordered by the azygos vein, right vagus nerve, and cardiac nerves. The stepwise, illustrated topographic anatomy addressed specific surgical demands and perspectives related to the left cervical approach and dissection of the esophagus, providing an anatomical basis to facilitate and safely implement the RACE procedure.

Histological study of the thin membranous dense connective tissue around the middle and lower thoracic esophagus, caudal to the bifurcation of the trachea

OBJECTIVE

We previously reported on the thin membranous dense connective tissue around the esophagus in the upper mediastinum. This time, we histologically investigated the existence of similar structures in the middle and lower mediastinum, caudal to the bifurcation of the trachea.

METHODS

Semi-sequential transverse sections of the mediastinum were obtained from two cadavers. Hematoxylin and eosin staining and Elastica van Gieson staining were performed.

RESULTS

In the middle mediastinum, the "visceral sheath" could not be observed completely around the esophagus. In the lower mediastinum, the thin membranous dense connective tissue was observed beneath the pericardium on the ventral side of the esophagus. On the dorsal side of the esophagus, two thin membranous dense connective tissues were similarly observed in two cadavers. One existed between the dorsal side of the esophagus and the three vessels (i.e., the descending aorta, the azygos vein and the thoracic duct) and was integrated with the thin membranous dense connective tissue of the ventral side of the esophagus at the bilateral side of the esophagus. This integrated dense connective tissue reached the left subpleural region and the adventitia of the aorta on the left side and the peripleural and pulmonary hilum on the right side. The other thin membranous dense connective tissue, which represents the "vascular sheath", was observed between the descending aorta and the thoracic duct.

CONCLUSION

These two thin membranous dense connective tissues, which are considered to represent the visceral sheath and vascular sheath, are thought to be available as optimal dissecting layers for radical esophagectomy.

Initial introduction of robot-assisted, minimally invasive esophagectomy using the microanatomy-based concept in the upper mediastinum

Background

We have recently standardized upper mediastinal lymph node dissection (UMLND) using a microanatomy-based concept in thoracoscopic esophagectomy in the prone position (TEPP), and introduced robot-assisted minimally invasive esophagectomy (RAMIE) using the same concept as in TEPP while aiming at solo surgery. The purpose of this study was to investigate the outcomes of RAMIE using the microanatomy-based concept in the initial introduction phase.

Methods

We have performed more than 500 TEPP procedures as minimally invasive esophagectomy (MIE). After performing about 400 cases of MIE, we established a microanatomy-based standardization of UMLND. In October 2018, we introduced RAMIE, and have performed 75 procedures in 20 months. Two groups were analyzed: a group after microanatomy-based standardization in TEPP (100 cases after completing 400 cases of TEPP) and a RAMIE group (75 cases). Finally, 51 paired cases were matched using a propensity score. Furthermore, the change in postoperative short-term outcome for RAMIE in the initial introduction phase was analyzed.

Results

Although there were no significant differences between the two groups in the number of upper mediastinal lymph nodes dissected, there was a significant decrease (P = 0.036) in intraoperative blood loss volume with RAMIE, representing a definite benefit for patients. The thoracoscopic operative time for RAMIE decreased by almost 100 min following less than 50 cases of experience, reaching the same level as that for recent TEPP, but with only one-tenth the operator experience. There were no significant differences in the total postoperative morbidity rate including the recurrent laryngeal nerve palsy rate.

Conclusion

RAMIE has been introduced safely and smoothly using the microanatomy-based concept established in TEPP.

Recent advances in minimally invasive esophagectomy for squamous esophageal cancer

Over the past decade there has been tremendous development in the clinical application of minimally invasive esophagectomy (MIE) for the treatment of squamous esophageal carcinoma. The major challenges in the performance of MIE include limitations in visualization and manipulation within the confined, rigid thoracic cavity; the need for adequate patient positioning and anesthetic techniques to accommodate the surgical exposure; and changes in the surgical steps for achieving radical nodal dissection, especially for the superior mediastinum. The surgical procedure for MIE is more and more standardized, and there is an increasing practice of MIE worldwide. Randomized trials and meta-analyses have confirmed the advantages of MIE over open esophagectomy, including a significantly lower rate of complications and shorter hospital stays. The recent application of robotics technologies for MIE has further enhanced the quality and safety of the surgical dissection, while intraoperative nerve monitoring has contributed to a lower rate of recurrent laryngeal nerve palsy. With the application of new technologies, we expect further improvement in surgical outcomes for MIE in the treatment of squamous esophageal cancer.

Transition from video-assisted thoracoscopic to robotic esophagectomy: a single surgeon's experience

Lymph node dissection (LND) along the left recurrent laryngeal nerve (RLN) is a technically challenging part of esophageal cancer surgery, especially after chemoradiotherapy (CRT). Robotic surgery holds promise to increase its safety and feasibility. The aim of this study was to describe a single thoracoscopic surgeon's experience related to the transition from video-assisted esophagectomy (VATE) to robotic esophagectomy (RE)-with a special focus on the safety of left RLN LND. Patients who underwent minimally invasive esophagectomy and RLN dissection following CRT were dichotomized according to the use of robotic surgery (robotic esophagectomy [RE] versus video-assisted thoracoscopic esophagectomy [VATE]). The following parameters were determined: (1) number of dissected nodes, (2) rates of RLN palsy, (3) rates of perioperative complications, and (4) learning curve. Learning curve analysis was performed using the 10-patient moving average (MA) for operation times and with the cumulative sum (CUSUM) method for left RLN LND (target failure rate: 15%). The RE and VATE groups consisted of 39 and 67 patients, respectively. The intraoperative identification of the left RLN was more common in the RE group (97.4%) than in the VATE group (68.7%; P < 0.001). Postoperative left RLN palsy was significantly more frequent in the VATE group (26.9%) than in the RE group (10.3%; P = 0.042), with a higher rate of pneumonia in the former (16.4% versus 2.6%; P = 0.03). The MA chart revealed a downward trend followed by a flattening of the RE operation time at operation number 17 and 29, respectively. CUSUM analysis showed that the left RLN palsy rate decreased to the target rate after 12 operations. We conclude that at least 12 cases are required for a surgeon with prior experience in VATE to safely accomplish left RLN LND through a robotic approach.

Lymph node dissection along the recurrent laryngeal nerves in patients with oesophageal cancer who had undergone chemoradiotherapy: is it safe?

OBJECTIVES

Upper mediastinal lymph node dissection (LND)-especially along the recurrent laryngeal nerve (RN)-is the most challenging part of oesophageal cancer surgery. We investigated whether thoracoscopic RN LND may be safely performed in patients with oesophageal cancer who had undergone chemoradiotherapy (CRT).

METHODS

Patients with oesophageal cancer who had undergone thoracoscopic RN LND (n = 103) were divided into 2 groups according to whether they had prior treatment with CRT or not [the CRT group (n = 65) vs the upfront surgery group (n = 38), respectively]. All patients were operated on by a single surgeon. Intergroup comparisons were made in terms of (i) the number of dissected nodes, (ii) rates of RN palsy and (iii) rates of perioperative complications. The learning curve for the RN LND procedure was investigated using the cumulative sum method.

RESULTS

RN LND after CRT was more technically challenging when performed in the left side. Complete skeletonization of the left RN was achieved only in 66.2% of patients in the CRT group (vs 86.8% in the upfront surgery group; P = 0.022). The rate of postoperative left side RN palsy was significantly higher in the CRT group (26.6%) than in the upfront surgery group (7.9%, P = 0.022), albeit resulting in neither higher pneumonia rates nor longer hospital stays. The cumulative sum analysis revealed a steep learning curve for left RN LND in the CRT group. Unfortunately, an acceptable proficiency (left RN palsy rate: 15%) was not achievable even after treatment in 65 cases.

CONCLUSIONS

Thoracoscopic RN LND is safe but poses significant challenges in CRT-treated patients.

Review of different approaches of the left recurrent laryngeal nerve area for lymphadenectomy during minimally invasive esophagectomy

In order to perform the total mediastinal lymphadenectomy during minimally invasive esophageal resection, doing the lymphadenectomy along the left recurrent laryngeal nerve (LRLN) may be a difficult part of this intervention. One reason is the need for the correct visualization of the area; another is not wanting to compromise the integrity of the nerve. In this review article the different modalities for approaching this upper mediastinal area by thoracoscopy are described.

ADAMTS-6 is a predictor of poor prognosis in patients with esophageal squamous cell carcinoma

BACKGROUND

A disintegrin and metalloprotease with thrombospondin motif (ADAMTS) enzymes play important roles in cell functions including adhesion, invasion, migration, and proliferation. ADAMTS-6 is a member of the ADAMTS family; reports of its relationship with esophageal squamous cell carcinoma (ESCC) progression are rare. It is unclear whether ADAMTS-6 could be an independent ESCC biomarker.

METHODS

ADAMTS-6 expression was detected by immunohistochemistry (IHC) in 171 paraffin-embedded ESCC specimens; relationships with patients' clinicopathological features and Twist-1 expression were analyzed by the Pearson Chi-square method, respectively. Overall survival (OS) and disease-free survival (DFS) were determined using the Kaplan-Meier method and compared using the long-rank test.

RESULTS

ADAMTS-6 was expressed mainly in the cytoplasm and nucleus; the expression was significantly higher in tumor tissues. Increased expression of ADAMTS-6 correlated with clinical stage (P = 0.009), pT stage (P = 0.042), lymph node metastasis (P = 0.014) and recurrence (P = 0.033). There were no significant correlations between ADAMTS-6 expression and other clinicopathological parameters including age, sex, tumor size, distant metastasis, differentiation, …chemotherapy, radiotherapy, CD68 expression and epithelial mesenchymal transition (EMT) status. Kaplan-Meier survival curves revealed that upregulated expression of ADAMTS-6 indicated short OS (P = 0.001) and DFS (P = 0.002). Multivariate analysis confirmed that high ADAMTS-6 expression was an independent factor for ESCC prognosis. ADAMTS-6 expression was significantly correlated with Twist-1 expression in ESCC cancer cells (P = 0.007) and stromal cells (P < 0.001). Patients with ESCC revealing expression of both ADAMTS-6 and Twist-1 exhibited significantly reduced OS and DFS rates than other patients.

CONCLUSIONS

High ADAMTS-6 expression is a useful marker of poor prognosis in patients with ESCC.