New insights into the surgical anatomy of the esophagus

Short-term outcomes of robot-assisted versus conventional minimally invasive esophagectomy for esophageal cancer: a systematic review and meta-analysis of 18,187 patients

The role of robotic surgery in the curative-intent treatment of esophageal cancer patients is yet to be defined. To compare short-term outcomes between conventional minimally invasive (cMIE) and robot-assisted minimally invasive esophagectomy (RAMIE) in esophageal cancer patients. PubMed, Web of Science and Cochrane Library were systematically searched. The included studies compared short-term outcomes between cMIE and RAMIE. Individual risk of bias was calculated using the MINORS and RoB2 scales. There were no statistically significant differences between RAMIE and cMIE regarding conversion to open procedure, mean number of harvested lymph nodes in the mediastinum, abdomen and along the right recurrent laryngeal nerve (RLN), 30- and 90-day mortality rates, chyle leakage, RLN palsy as well as cardiac and infectious complication rates. Estimated blood loss (MD - 71.78 mL, p < 0.00001), total number of harvested lymph nodes (MD 2.18 nodes, p < 0.0001) and along the left RLN (MD 0.73 nodes, p = 0.03), pulmonary complications (RR 0.70, p = 0.001) and length of hospital stay (MD - 3.03 days, p < 0.0001) are outcomes that favored RAMIE. A significantly shorter operating time (MD 29.01 min, p = 0.004) and a lower rate of anastomotic leakage (RR 1.23, p = 0.0005) were seen in cMIE. RAMIE has indicated to be a safe and feasible alternative to cMIE, with a tendency towards superiority in blood loss, lymph node yield, pulmonary complications and length of hospital stay. There was significant heterogeneity among studies for some of the outcomes measured. Further studies are necessary to confirm these results and overcome current limitations.

Robotic Versus Conventional Minimally Invasive Esophagectomy for Esophageal Cancer: A Meta-analysis

OBJECTIVES

To give a comprehensive review of the literature comparing perioperative outcomes and long-term survival with robotic-assisted minimally invasive esophagectomy (RAMIE) versus minimally invasive esophagectomy (MIE) for esophageal cancer.

BACKGROUND

Curative minimally invasive surgical treatment for esophageal cancer includes RAMIE and conventional MIE. It remains controversial whether RAMIE is comparable to MIE.

METHODS

This review was registered at the International Prospective Register of Systematic Reviews (CRD42021260963). A systematic search of databases was conducted. Perioperative outcomes and long-term survival were analyzed and subgroup analysis was conducted. Cumulative meta-analysis was performed to track therapeutic effectiveness.

RESULTS

Eighteen studies were included and a total of 2932 patients (92.88% squamous cell carcinoma, 29.83% neoadjuvant therapy, and 38.93% stage III-IV), 1418 underwent RAMIE and 1514 underwent MIE, were analyzed. The number of total lymph nodes (LNs) [23.35 (95% CI: 21.41-25.29) vs 21.98 (95% CI: 20.31-23.65); mean difference (MD) = 1.18; 95% CI: 0.06-2.30; P =0.04], abdominal LNs [9.05 (95% CI: 8.16-9.94) vs 7.75 (95% CI: 6.62-8.88); MD = 1.04; 95% CI: 0.19-1.89; P =0.02] and LNs along the left recurrent laryngeal nerve [1.74 (95% CI: 1.04-2.43) vs 1.34 (95% CI: 0.32-2.35); MD = 0.22; 95% CI: 0.09-0.35; P <0.001] were significantly higher in the RAMIE group. RAMIE is associated with a lower incidence of pneumonia [9.61% (95% CI: 7.38%-11.84%) vs 14.74% (95% CI: 11.62%-18.15%); odds ratio = 0.73; 95% CI: 0.58-0.93; P =0.01]. Meanwhile, other perioperative outcomes, such as operative time, blood loss, length of hospital stay, 30/90-day mortality, and R0 resection, showed no significant difference between the two groups. Regarding long-term survival, the 3-year overall survival was similar in the two groups, whereas patients undergoing RAMIE had a higher rate of 3-year disease-free survival compared with the MIE group [77.98% (95% CI: 72.77%-82.43%) vs 70.65% (95% CI: 63.87%-77.00%); odds ratio = 1.42; 95% CI: 1.11-1.83; P =0.006]. A cumulative meta-analysis conducted for each outcome demonstrated relatively stable effects in the two groups. Analyses of each subgroup showed similar overall outcomes.

CONCLUSIONS

RAMIE is a safe and feasible alternative to MIE in the treatment of resectable esophageal cancer with comparable perioperative outcomes and seems to indicate a possible superiority in LNs dissection in the abdominal cavity, and LNs dissected along the left recurrent laryngeal nerve and 3-year disease-free survival in particular in esophageal squamous cell carcinoma. Further randomized studies are needed to better evaluate the long-term benefits of RAMIE compared with MIE.

Mechanisms of esophageal cancer metastasis and treatment progress

Esophageal cancer is a prevalent tumor of the digestive tract worldwide. The detection rate of early-stage esophageal cancer is very low, and most patients are diagnosed with metastasis. Metastasis of esophageal cancer mainly includes direct diffusion metastasis, hematogenous metastasis, and lymphatic metastasis. This article reviews the metabolic process of esophageal cancer metastasis and the mechanisms by which M2 macrophages, CAF, regulatory T cells, and their released cytokines, including chemokines, interleukins, and growth factors, form an immune barrier to the anti-tumor immune response mediated by CD8+ T cells, impeding their ability to kill tumor cells during tumor immune escape. The effect of Ferroptosis on the metastasis of esophageal cancer is briefly mentioned. Moreover, the paper also summarizes common drugs and research directions in chemotherapy, immunotherapy, and targeted therapy for advanced metastatic esophageal cancer. This review aims to serve as a foundation for further investigations into the mechanism and management of esophageal cancer metastasis.

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.

Outcomes of minimally invasive total mesoesophageal excision: a propensity score-matched analysis

BACKGROUND

This study aimed to investigate the safety and efficacy of minimally invasive total mesoesophageal excision (TME) for esophageal cancer.

METHODS

We retrospectively collected data from patients with esophageal cancer who underwent esophagectomy at our center between January 2011 and June 2017. Among 611 eligible patients, 302 underwent minimally invasive total mesoesophageal excision (the TME group) and 309 underwent non-total mesoesophageal excision (the NME group). Outcomes were compared after 1-to-1 propensity score matching, and subgroup analyses were performed for cases involving pT1-2 or pT3-4a disease.

RESULTS

The propensity score matching produced 249 pairs of patients. The TME group had a shorter operative time (P < 0.001), lower intraoperative bleeding (P < 0.001), and a shorter postoperative hospital stay (P < 0.001). There were no significant differences between the two groups in the number of removed lymph nodes, 30-day mortality, or postoperative complications. In addition, both groups had similar 3-year rates of overall survival (OS) and disease-free survival (DFS). However, the 3-year recurrence rate in the esophageal bed was significantly lower in the TME group (P = 0.033). Furthermore, among patients with pT3-4a disease, the TME group had better 3-year rates of OS, DFS, and recurrence.

CONCLUSION

Minimally invasive total mesoesophageal excision appears to be a safe technique that can reduce tumor recurrence in the esophageal bed. Furthermore, this technique provided survival benefits for patients with pT3-4a disease.

Metallothionein 2A Expression in Cancer-Associated Fibroblasts and Cancer Cells Promotes Esophageal Squamous Cell Carcinoma Progression

Simple Summary

Cancer-associated fibroblasts (CAFs) are tumor promoters in various cancers. We previously reported a correlation between the high expression of the CAF marker fibroblast activation protein and poor prognosis of esophageal squamous cell carcinoma (ESCC). We also found that metallothionein 2A (MT2A) is highly expressed in CAF-like cells that we established. In the current study, we explored the role of MT2A in ESCC progression. MT2A expression in the CAF-like cells induced expression and secretion of insulin-like growth factor binding protein 2 (IGFBP2), which promoted the migration and invasiveness of ESCC cells through the NFκB, Akt, and Erk signaling pathways. Furthermore, MT2A was involved in ESCC cell growth, migration, and invasiveness. Moreover, high expression of MT2A in the cancer tissue correlated with poor prognosis of ESCC patients. Briefly, we demonstrate that MT2A and IGFBP2 are potential novel therapeutic targets in ESCC.

Abstract

Esophageal cancer has the sixth highest mortality rate worldwide. Cancer-associated fibroblasts (CAFs) are involved in the progression of various cancers. Previously, we demonstrated an association between high expression of the CAF marker, fibroblast activation protein, and poor prognosis of esophageal squamous cell carcinoma (ESCC). We also established CAF-like cells by indirect co-culture of bone marrow-derived mesenchymal stem cells with ESCC cell lines and found metallothionein 2A (MT2A) to be highly expressed in them. Here, to explore the function of MT2A in CAFs, we silenced MT2A in the CAF-like cells and ESCC cell lines using small interfering RNA. MT2A knockdown in the CAF-like cells suppressed expression and secretion of insulin-like growth factor binding protein 2 (IGFBP2); recombinant IGFBP2 promoted migration and invasiveness of ESCC cells via NFκB, Akt, and Erk signaling pathways. Furthermore, MT2A knockdown in the ESCC cell lines inhibited their growth, migration, and invasiveness. Immunohistochemistry demonstrated that high MT2A expression in the cancer stroma and cancer nest of ESCC tissues correlated with poor prognosis of ESCC patients. Hence, we report that MT2A in CAFs and cancer cells contributes to ESCC progression. MT2A and IGFBP2 are potential novel therapeutic targets in ESCC.

Multifactorial dysphagia: Azygos vein aneurysm (AVA) and esophagogastric junction outflow obstruction (EGJOO)

Introduction

Vascular impingement of the esophagus is a rare cause of dysphagia, and is most commonly due to aortic arch anomalies such as arterial lusoria. Dysphagia resultant from venous compression is even further less likely.

Presentation of case

We present a highly unusual case of dysphagia secondary to a large aneurysm of the azygous vein near its confluence with the superior vena cava, which was managed with endovascular modalities. Despite initial treatment success, patient reported some intermittent solid food dysphagia, and was also found to have esophagogastric junction outflow obstruction (EGJOO) on high resolution impedance manometry (HRIM) which was successfully managed with surgical myotomy and partial fundoplication.

Discussion

The azygos vein has an intimate anatomic relationship with the esophagus as it traverses the posterior mediastinum. Because of this anatomic association, the azygos vein may present a point of esophageal obstruction in the setting of significant pathology.

Conclusion

This case highlights the possibility of multifactorial causes of dysphagia, and that HRIM is a key aspect of this workup. Additionally we discuss the pertinent anatomy, diagnosis, and treatments for azygos vein aneurysm and EGJOO.

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Vascular impingement of the esophagus is a rare cause of dysphagia.

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This type of dysphagia is most commonly due to aortic arch anomalies such as arterial lusoria.

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The azygos vein may present a point of esophageal obstruction in the setting of significant pathology.

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Endovascular therapy in selected patients can provide resolution of dysphagia in patients with azygos vein aneurysm.

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There is possibility of multifactorial causes of dysphagia, and high resolution manometry is a key aspect of this workup.

Severe tracheobronchial harm due to lithium button battery aspiration: An in vitro study of the pathomechanism and injury pattern

BACKGROUND

Button battery incidents have become a rising medical issue in recent years, especially for infants. The increasing number of these cases can be explained by the expanding use of objects of everyday life and toys. As a result, button batteries in many households are ubiquitous in different states of charge. The extremely long shelf-life and the increasing energy densities of lithium button batteries boost the potential medical complications of accidental swallowing.

OBJECTIVE

The study aimed to analyze the pathophysiology of damage to tracheobronchial structures by button batteries aspiration over time.

METHODS

CR2032 and CR927 lithium button batteries (3.2/3.0 V) were exposed to porcine trachea preparations intraluminal at 37 °C in intervals up to 36 h. Measurements were made of the voltage curve, the discharge current, and the resulting pH values around the electrodes. The effects on tissue were examined using macroscopic time-lapse images and microscopic pictures of sections of the fixed specimens over time.

FINDINGS

The examinations showed a tissue electrolysis reaction directly after the beginning of battery exposure, which led to an immediate coagulation impairment of the respiratory epithelium. Over time, a strongly alkaline environment was established around the batteries. The resulting tissue colliquation caused profound tissue damage beyond the basal membrane of the mucosa, affecting the tracheobronchial cartilage after only 4 h of exposure time. After 12 h, there was significant necrosis of the annular ligaments of the trachea and the peribronchial pulmonary tissue. After completion of the experimental exposure time of 36 h, there was still a sufficient residual voltage on all button batteries of the experiments.

CONCLUSIONS

Besides accidental ingestion, the aspiration of button batteries is a life-threatening situation. The partial or complete acute airway obstruction in the trachea or the bronchi initially is the leading symptom, as with any foreign body aspiration. However, the results of the investigations show that even after a short exposure time, relevant tissue damage can be caused by the electrolysis reaction of the battery. After 12 h, a profound destruction of cartilage, connective tissue, and smooth muscles was observed in vitro, which may cause significant consequential damage in vivo. These findings reveal the need for rapid diagnosis and immediate foreign body removal after any battery ingestion. Moreover, the results show how relevant prevention of these accidents is, and that future safety modifications of these types of battery by the manufacturers would be appropriate.

Computed tomography angiography study of the azygos vein course and termination into superior vena cava: gender and age impact

PURPOSE

The study highlights azygos vein (AV) topography, arrangement and confluence morphometry in dyspnoea and tachycardia patients of extrapulmonary and extracardiac aetiology.

METHOD

Computed-tomography angiography of 25 male and 26 female patients (mean age 66.5 years) were studied for: thoracic vertebral (T) height of AV- superior vena cava-SVC confluence, AV course and deviations from vertebral column (VC) midline, AV and SVC diameters, distance (AV arch- lower border of carina) and gender and age impact.

RESULTS

Commonest heights of the AV-SVC confluence were T5 (56.9%), T4 (31.4%), T6 (9.8%) and T3 (2%). The AV terminated into SVC after crossing the left side of VC midline in 56.9%, slightly deviated right of the midline in 37.3% and coursed right of VC in 5.9%. Mean AV and SVC diameters were 0.96 ± 0.18 cm and 1.86 ± 0.27 cm. Male predominance in AV and SVC diameters and a slight AV diameter significant increase with the age were found. The (AV highest point-lower border of carina) mean distance was 2.05 ± 0.44 cm and male predominance existed.

CONCLUSION

The commonest termination height of the AV was T5, while T3 was the rarest one. Aging induces the AV leftward displacement, while gender had no impact. AV and SVC diameters had higher significant values in males, while ageing had a significant impact only in AV diameter. The AV higher diameters will be used as predictors for higher values of SVC diameter and mediastinum pathology. Such findings can be useful in mediastinal surgery, mediastinoscopy and surgery of VC deformations, neurovascular surgery of retroperitoneal organs, disc herniation and T fractures.

Death unrelated to cancer and death from aspiration pneumonia after definitive radiotherapy for head and neck cancer

BACKGROUND AND PURPOSE

The incidence of hypopharyngeal and supraglottic cancer (HSC) is high in Japan. This study aimed to retrospectively identify risk factors for death unrelated to cancer and death from aspiration pneumonia after definitive radiotherapy (RT) for HSC.

MATERIALS AND METHODS

Overall, 391 patients who began definitive RT for HSC between 2006 and 2014 were identified from the Osaka International Cancer Institute electronic database. Among 391 patients, 33 had a history of surgery for esophageal cancer (EC) and 19 received simultaneous RT for synchronous EC. The cause of death was divided into 3 main categories: "cancer under study," "other malignancy," and "unrelated to cancer." Cox proportional hazard model was used to estimate the hazard ratio (HR).

RESULTS

The median follow-up for survivors was 8 (range 3.6-14.1) years. At the last follow-up, 202 patients died. Death from "cancer under study," "other malignancy," and "unrelated to cancer" occurred in 92 (45.5%), 55 (27.2%), and 55 (27.2%) patients, respectively. Twelve patients died from aspiration pneumonia. In multivariate analysis for death unrelated to cancer and death from aspiration pneumonia, history of surgery for EC (HR: 3.87, p < 0.001; HR: 6.84, p = 0.007, respectively) and simultaneous RT for synchronous EC (HR: 3.74, p = 0.006; HR: 16.37, p < 0.001, respectively) were significant risk factors.

CONCLUSION

The laryngeal preservation approach by RT for HSC patients with a history of surgery for EC and simultaneous RT for synchronous EC should be used with caution.

In vivo positron emission tomography imaging of decreased parasympathetic innervation in the gut of vagotomized patients

BACKGROUND

Parasympathetic neuropathy is a key feature in many common disorders, including diabetes, neurological disorders, and cancers, but few objective methods exist for assessing damage to the parasympathetic nervous system, particularly in the gastrointestinal system. This study aimed to validate the use of ¹¹ C-donepezil positron emission tomography (PET) to assess parasympathetic integrity in a group of vagotomized patients.

METHODS

Sixteen healthy controls and 12 patients, vagotomized due to esophagectomy, underwent ¹¹ C-donepezil PET, measurement of colonic transit time, quantification of plasma pancreatic polypeptide (PP), and assessment of subjective long-term symptoms.

KEY RESULTS

Vagotomized patients had significantly decreased PET signal in the small intestine and colon compared with healthy controls (5.7 [4.4-7.9] vs 7.4 [4.5-11.3], P = .01 and 1.4 [1.1-2.1] vs 1.6 [1.4-2.4], P < .01, respectively). Vagotomized patients also displayed a significantly increased colonic transit time (2.9 ± 0.9 h vs 1.9 ± 0.8 h), P < .01 and increased volumes of the small intestine and colon (715 ccm [544-1177] vs 443 ccm [307-613], P < .01 and 971 ccm [713-1389] vs 711 ccm [486-1394], P = .01, respectively). Patients and controls did not differ in PP ratio levels after sham feeding, but PP ratio at 10 minutes. after sham feeding and PET signal intensity in the small intestine was positively correlated (P = .03).

CONCLUSIONS AND INFERENCES

We found significantly decreased ¹¹ C-donepezil signal in the intestine of vagotomized patients, supporting that ¹¹ C-donepezil PET is a valid measure of intestinal parasympathetic denervation.

Comparison of the short-term outcomes of robot-assisted minimally invasive, video-assisted minimally invasive, and open esophagectomy

Background

The development of minimally invasive surgery has initiated many changes in the surgical treatment of esophageal cancer (EC) patients. The aim of this study was to compare the short-term outcomes of robotic-assisted minimally invasive esophagectomy (RAMIE), video-assisted minimally invasive esophagectomy (VAMIE), and open esophagectomy (OE).

Methods

Our study included patients who had undergone McKeown esophagectomy at Tianjin Medical University Cancer Institute and Hospital between January 2016 and December 2018. We analyzed clinical baseline data, as well as perioperative and pathological outcomes.

Results

A total of 312 cases met the inclusion criteria (OE: 77, VAMIE: 144, RAMIE: 91). The OE group had a greater number of late-stage patients as well as those who received the neo-adjuvant therapy, compared with the other two groups (P=0.001). The procedure time in the OE group was also shorter by approximately 20 minutes (P=0.021). Total blood loss was significantly lower in the two MIE groups (P=0.004) than in the OE group. There were no differences in the total number of dissected lymph nodes between the three groups (OE: 24.09±10.77, VAMIE: 23.07±10.18, RAMIE: 22.84±8.37, P=0.680). Both the lymph node number (P=0.155) and achievement rate (P=0.190) in the right recurrent laryngeal nerve (RLN) area were comparable between the three groups. However, in the left RLN area, minimally invasive approaches resulted in a higher number of harvested lymph nodes (P=0.032) and greater achievement rate (P=0.018). Neither MIE procedure increased the incidence of postoperative complications.

Conclusions

Minimally invasive surgery could guarantee the quality of bilateral RLN lymphadenectomy without increasing postoperative complications, especially in RAMIE patients. The rational choice of different surgical approaches would improve both safety and oncological outcomes for patients.

Robotic-assisted minimally invasive esophagectomy: past, present and future

Esophagectomy for cancer of the esophagus is increasingly performed using minimally invasive techniques. After the introduction of minimally invasive esophagectomy (MIE) in the early 1990's, robotic-assisted techniques followed after the turn of the millennium. The advent of robotic platforms has allowed the development of robotic-assisted minimally invasive esophagectomy (RAMIE) over the past 15 years. Although recent trials have shown superior peri-operative morbidity and quality of life compared to open esophagectomy, no randomized trials have compared RAMIE to conventional MIE. This paper summarizes the current literature on RAMIE and provides an overview of expected future developments in robotic surgery.

The development of the dorsal mesentery in human embryos and fetuses

The vertebrate intestine has a continuous dorsal mesentery between pharynx and anus that facilitates intestinal mobility. Based on width and fate the dorsal mesentery can be subdivided into that of the caudal foregut, midgut, and hindgut. The dorsal mesentery of stomach and duodenum is wide and topographically complex due to strong and asymmetric growth of the stomach. The associated formation of the lesser sac partitions the dorsal mesentery into the right-sided "caval fold" that serves as conduit for the inferior caval vein and the left-sided mesogastrium. The thin dorsal mesentery of the midgut originates between the base of the superior and inferior mesenteric arteries, and follows the transient increase in intestinal growth that results in small-intestinal looping, intestinal herniation and, subsequently, return. The following fixation of a large portion of the abdominal dorsal mesentery to the dorsal peritoneal wall by adhesion and fusion is only seen in primates and is often incomplete. Adhesion and fusion of mesothelial surfaces in the lesser pelvis results in the formation of the "mesorectum". Whether Toldt's and Denonvilliers' "fasciae of fusion" identify the location of the original mesothelial surfaces or, alternatively, represent the effects of postnatal wear and tear due to intestinal motility and intra-abdominal pressure changes, remains to be shown. "Malrotations" are characterized by growth defects of the intestinal loops with an ischemic origin and a narrow mesenteric root due to insufficient adhesion and fusion.