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

Evaluating a Single Surgeon's Learning Curve for Laparoscopic Totally Extraperitoneal Repair of Inguinal Hernia with Telescopic Dissection: A Cumulative Sum Control Chart Analysis

Background: Laparoscopic totally extraperitoneal (TEP) inguinal hernia repair (IHR) reduces risk of injury to intraperitoneal structures. Balloon dissection is more costly and has theoretical risk of injury to the surrounding structures compared with telescopic dissection (TD). This study aims to evaluate the learning curve (LC) for TEP IHR with TD of a single surgeon. Methods: This is a 3-year retrospective cohort study from January 2020 to December 2022 on patients who underwent elective laparoscopic TEP unilateral IHR with TD. Exclusion criteria were recurrent inguinal hernia. Cumulative sum (CUSUM) analysis was performed to evaluate the number of cases required to surmount the LC, that is, NLC for operating time (OT) and open conversion. One way analysis of variance was used to perform groupwise comparison. Results: There were 69 patients who underwent laparoscopic TEP unilateral IHR with TD. The median age was 58.0 years (range 24.0-80.0) and body mass index was 23.0 (range 18.6-30.0). Majority of the hernia was indirect (n = 48, 69.6%). The median OT was 70 minutes (range 35-210). Three cases (4.3%) had open conversion. One-year recurrence was 4.2% (n = 1/24). CUSUM analysis showed improvement in OT after the eighth case. However, this was followed by multiple inflection points with no apparent stabilization in OT. Pairwise comparison showed a decrease in OT between cases 18-36 and cases 37-54. There was no incidence of open conversion until the 56th case. Conclusion: Laparoscopic TEP IHR using TD is safe in the absence of a practor. A minimum of 36 cases is required to surmount the initial LC.

Exploring the learning curve in minimally invasive esophagectomy: a systematic review

Minimally invasive esophagectomy (MIE) has been shown to be superior to open esophagectomy with reduced morbidity, mortality, and comparable lymph node (LN) harvest. However, MIE is technically challenging. This study aims to perform a pooled analysis on the number of cases required to surmount the learning curve (LC), i.e. NLC in MIE. PubMed, Embase, Scopus, and the Cochrane Library were systematically searched for articles from inception to June 2022. Inclusion criteria were articles that reported LC in video-assisted MIE (VAMIE) and/or robot-assisted MIE (RAMIE). Poisson means (95% confidence interval [CI]) was used to determine NLC. Negative binomial regression was used for comparative analysis. There were 41 articles with 45 data sets (n = 7755 patients). The majority of tumors were located in the lower esophagus or gastroesophageal junction (66.7%, n = 3962/5939). The majority of data sets on VAMIE (n = 16/26, 61.5%) used arbitrary analysis, while the majority of data sets (n = 14/19, 73.7%) on RAMIE used cumulative sum control chart analysis. The most common outcomes reported were overall operating time (n = 30/45) and anastomotic leak (n = 28/45). Twenty-four data sets (53.3%) reported on LN harvest. The overall NLC was 34.6 (95% CI: 30.4-39.2), 68.5 (95% CI: 64.9-72.4), 27.5 (95% CI: 24.3-30.9), and 35.9 (95% CI: 32.1-40.2) for hybrid VAMIE, total VAMIE, hybrid RAMIE, and total RAMIE, respectively. NLC was significantly lower for total RAMIE compared to total VAMIE (incidence rate ratio: 0.52, P = 0.032). Studies reporting NLC in MIE are heterogeneous. Further studies should clearly define prior surgical experiences and assess long-term oncological outcomes using non-arbitrary analysis.

A comparison of two methods of lymph node dissection along the left recurrent laryngeal nerve in McKeown minimally invasive esophagectomy

Background

Lymph nodes dissection in esophagectomy is an essential procedure for radical resection, which can not only provide more accurate staging but may also improve survival, while it is technically challenging and may lead to recurrent laryngeal nerve (RLN) paralysis. Numerous efforts have been directed to achieve the dissection of more LNs around the RLN and to lower the incidence of RLN palsy, including Bascule method and modified Bascule method. On this basis, we modified and applied a novel method which involves the en bloc dissection of lymph nodes dissection along the left RLN in McKeown minimally invasive esophagectomy (MIE).

Methods

A total of 244 consecutive cases of lymphadenectomy along the left RLN during McKeown MIE at our institution between January 2018 and August 2021 were retrospectively analyzed. The cases were divided into two groups based on the methods of lymphadenectomy along the left RLN: 77 cases received the conventional method (CM group) and 167 cases received the novel method (NM group). The surgical outcomes, especially the impact of surgical proficiency on the outcomes of lymphadenectomy along the left RLN, were assessed and compared between the two groups.

Results

Demographic data of the two cohorts were similar. The number of harvested lymph nodes (LNs) (total/abdomen/left RLN) in the NM group was markedly higher than that in the CM group (32 vs. 27, P=0.006; 11 vs. 9, P=0.038; 3 vs. 2, P=0.044). However, the number of harvested LNs from the chest or right RLN was not significantly different in the two groups. The hoarseness rate was 1.8% in the NM group, which was slightly but not notably lower than that of the CM group (1.8% vs. 2.6%, P=0.681). The incidence of LN metastasis along the left RLN was 13.9%, 15.6%, and 13.2% in the whole cohort, CM group, and NM group, respectively.

Conclusions

Our novel method not only increased the number of LN dissections along left RLN but also slightly reduced the incidence of hoarseness. Therefore, this novel method of lymphadenectomy along the left RLN during McKeown MIE is safe and reliable.