The efficacy and feasibility of neoadjuvant immunotherapy plus chemotherapy followed by McKeown minimally invasive oesophagectomy for locally advanced oesophageal squamous cell carcinoma

Introduction

In immunotherapy, antibodies are activated to block immune checkpoints, resist tumour immunosuppression, shrink tumours and prevent a recurrence. As the science behind tumour immunotherapy continuously develops and improves, neoadjuvant immunotherapy bears more prominent advantages: antigen exposure not only enhances the degree of tumour-specific T-cell response but also prolongs the duration of actions. In this study, we evaluated the efficacy and safety of McKeown minimally invasive oesophagectomy (McKeown MIO) following neoadjuvant immunotherapy combined with chemotherapy (NICT) in patients with locally advanced oesophageal cancer (OC).

Patients and Methods

In this retrospective study, 94 patients underwent either NICT or neoadjuvant chemotherapy (NCT) followed by MIO at our institution from January 2020 to October 2022. We assessed the therapy-related adverse events and perioperative outcomes and compared them between the two groups.

Results

After completing at least two cycles of neoadjuvant therapy, all patients underwent McKeown MIO with negative margins within 4-7 weeks. Demographic data of the two cohorts were similar. Regarding perioperative characteristics, the median intraoperative blood loss was 50 ml in the NICT group, lower than that of the NCT group (100 ml, P < 0.05). In addition, the NICT group had significantly more harvested lymph nodes than the NCT group (P < 0.05). No significant differences were found in post-operative complications. The rate of objective response rate in the NICT group was higher than that in the NCT group (88.3% vs. 58.8%). Regarding tumour regression, the number of patients with TRG Grades 1-3 in the NICT group was more than that in the NCT. Adverse events experienced by the two groups included anaemia and elevated transaminase. We found no difference in the adverse events between the two groups.

Conclusions

This study showed the efficacy and feasibility of NICT followed by McKeown MIO in treating locally advanced OC.

Learning Curve for Lymph Node Dissection Around the Recurrent Laryngeal Nerve in McKeown Minimally Invasive Esophagectomy

Background

Compared to open esophagectomy (OE), minimally invasive esophagectomy (MIE) is associated with lower morbidity and mortality. However, lymph node (LN) dissection around the recurrent laryngeal nerve (RLN) is still an important factor that affects the length of the learning curve of MIE. This study aims to evaluate the surgical outcomes of the first nearly 5-year period and explore the learning curve for LN dissection around the RLN in McKeown MIE by a new single surgical team.

Methods

A total of 285 consecutive patients who underwent McKeown MIE between March 2016 and September 2020 were included at our institution. According to the cumulative sum (CUSUM) analysis of LN dissection around the RLN, the patients were divided into three groups: exploration period, adjustment period, and stable period. We assessed the impact of surgical proficiency on postoperative outcomes and explored the learning curve for LN dissection around the RLN in McKeown MIE.

Results

The CUSUM graph showed that a point of upward inflection for LN dissection around the RLN was observed in 151 cases. After 151 cases, LNs around the right and left RLNs were dissected thoroughly compared to the exploration and adjustment period (P = 0.010 and P = 0.012, respectively), and the postoperative incidence of hoarseness significantly decreased from 11.1 to 1.5% (P<0.001).

Conclusions

Our study results revealed that not only are the LN, around the RLN, sufficiently dissected but also the incidence of hoarseness significantly decreased in the stable phase. Consequently, the learning curve length was approximately 151 cases for LN dissection around the RLN in McKeown MIE.

Efficacy of Indocyanine Green Fluorescence Angiography in Preventing Anastomotic Leakage After McKeown Minimally Invasive Esophagectomy

Background

Indocyanine green (ICG) fluorescence angiography (FA) was introduced to provide real-time intraoperative evaluation of the vascular perfusion of the gastric conduit during esophagectomy. However, its efficacy has not yet been proven. The aim of this study was to assess the usefulness of ICG-FA in the reduction of the rates of anastomotic leakage (AL) in McKeown minimally invasive esophagectomy (MIE).

Methods

From June 2017 to December 2019, patients aged between 18 and 80 years with esophageal carcinoma were enrolled in the study and each patient underwent McKeown MIE. Patients were divided into two groups, those with or without ICG-FA. The patient demographics and perioperative outcomes were comparable between the two groups. The primary outcome was the rate of AL.

Results

A total of 192 patients were included: 86 in the ICG-FA group and 106 in the non-ICG-FA group. Overall, 12 patients (6.3%) had AL; the rate of AL was 10.4% in the non-ICG-FA group, which was significantly higher than the 1.2% in the ICG-FA group.

Conclusions

ICG-FA has the potential to reduce the rate of AL in McKeown MIE.

Clinical analysis of minimally invasive McKeown esophagectomy in a single center by a single medical group

OBJECTIVE

McKeown esophagectomy followed by cervical and abdominal procedures has been commonly used for invasive esophageal carcinoma. This minimally-invasive operative procedure in the lateral prone position has been considered to be the most appropriate method. We describe our experiences in minimally invasive McKeown esophagectomy (MIME) for esophageal cancer.

METHODS

Between March 2016 and February 2018, a total of 82 patients underwent MIME by a single group in our department (a single center). All procedure, operation, oncology, and complication data were reviewed.

RESULTS

All MIME procedures were completed successfully, with no conversions to open surgery. The median operative time was 260 min, and median blood loss was 100 ml. The average number of total harvested lymph nodes was 20.1 in the chest and 13.5 in the abdomen. There were no deaths within 30 postoperative days. Twenty cases (24.4%) developed postoperative complications, including anastomotic leak in 4 (4.9%), single lateral recurrent nerve palsy in 4 (4.9%), bilateral recurrent nerve palsy in 1 (1.2%), pulmonary problems in 3 (3.7%), chyle leak in 1 (1.2%), and other complications in 7 (including pleural effusions in 4, incomplete ileus in 2, and neck incision infection in 1; 8.54%). Average postoperative hospitalization time was 12 d. Blood loss, operation time, morbidity rate, and the number of harvested lymph nodes were analyzed by evaluating learning curves in different periods. Significant differences were found in operative time (P=0.006), postoperative hospitalization days (P=0.015), total harvested lymph nodes (P=0.003), harvested thoracic lymph nodes (P=0.006), and harvested abdominal lymph nodes (P=0.022) among different periods.

CONCLUSIONS

Surgical outcomes following MIME for esophageal cancer are safe and acceptable. The MIME procedure for stages I and II could be performed proficiently and reached an experience plateau after approximately 25 cases.

Effects of Ilexonin A on circulatory neuroregulation

Ilexonin A (IA), a pentacyclic triterpene, has been semisynthesized in china for the first time. It is extracted from the root of Ilicis pubescentis, a commonly used herbal medicine in Guangdong for the treatment of cardiovascular, cerebrovascular and peripheral vascular diseases and heart failure with satisfactory effects. The pharmacokinetic studies indicated that the elimination half-life after oral and i.v. dosing were 17.7 +/- 2.4 h and 22.5 +/- 2.9 h respectively. The total clearance was 4.6 +/- 0.51/h. The bioavailability of IA capsules was 0.39 +/- 0.14 and LD50 was 234 mg/Kg. We have adopted modern techniques, including cellular electrophysiology, isotope tracing methods, molecular biology, electromicroscopy, etc., to probe into the pharmacologic mechanisms of the effects of IA on cardiovascular system. The results indicated that IA can increase the contractility of isolated guinea pig auricular myocardium, attenuate vascular smooth muscle tension induced by noradrenaline in the rabbit aorta. IA can exert a biphasic regulatory effect on arterial blood pressure. IA also can prolong A-V duration of Hiss bundle electrograph (HBE) in rabbits and prolong the action potential duration and the effective refractory period (ERP) of myocardial cells in guinea pigs. The results showed that IA can increase the cAMP content in the smooth muscle of aorta and exert a calcium-blockade effect. Therefore, the peripheral resistance vessels are relaxed and the cardiac afterload is lowered. IA-blocked calcium channels are correlated with both the potential-dependent channel and the receptor operated channel in vascular smooth muscles. IA also increases the cAMP content of myocardium and accelerates the cellular calcium influx and efflux, and this may be responsible for the direct mechanism of the positive inotropic action of IA. Under electron microscopy, it is observed that IA can alleviate the defect of succinate dehydrogenase in the myocardial mitochrondria of rabbit chronic congestive heart failure (CF) model and reduce the microstructural damage of the failed myodardium, therefore the anoxic tolerance of myocardium is increased, the effect of IA on the platelet stretching activity and microstructure in the patients with CF is also studied. It is found that IA can reduce the hypercoagulability of blood, decrease the severity of blood stagnation and improve the status of microcirculation. Effects of IA introventricular and cardiovascular central microinjection (nucleus tractus solitarius, paraventricular nucleus) on arterial blood pressure and heart rate were studied. It demonstrated that IA possess circulatory neuroregular effects by the medium of alpha-receptor and beta-receptor of cardiovascular motoneurons.

Dynamic changes in venous outflow by baroreflex and left ventricular distension

We examined the dynamic changes in venous outflow from the splanchnic and extrasplanchnic vascular beds in response to carotid sinus (CS) baroreflex and left ventricular (LV) distension in 12 dogs anesthetized with pentobarbital sodium. Splenic sympathetic nerve activity was measured in an additional group of six dogs. A heart-lung bypass was used with constant cardiac output and constant venous pressure. LV distension was produced by inflating a balloon in the LV. LV distension and an increase in CS pressure from 50 to 200 mmHg decreased blood pressure by 26 +/- 5 and 30 +/- 6 mmHg and increased vascular capacitance by 5.5 +/- 0.9 and 4.5 +/- 1.2 ml/kg, respectively. Splanchnic venous outflow exhibited a transient decrease, whereas extrasplanchnic venous outflow showed a transient increase, in response to LV distension and increasing CS pressure, accompanied by a sustained decrease in splenic nerve activity. The results indicate important differences between splanchnic and extrasplanchnic components of the total venous system in terms of the regulation of venous capacitance. It is suggested that changes in venous capacitance produced by LV distension and CS baroreflex are primarily due to active changes in splanchnic venous tone.