Risk Factors of Mucosal Injury During Laparoscopic Heller Cardiomyotomy

INTRODUCTION

Achalasia represents an oesophagal motility disease in which there is oesophagal aperistalsis and failed relaxation of the lower oesophagal sphincter (LES)¹. It results from progressive degeneration of the myenteric oesophagal plexus^2,3. It is a rare clinical entity, with an incidence and prevalence of one and ten per 100000 individuals, respectively ⁴. The patient usually presents with difficulty swallowing, regurgitation, weight loss, and chest pain ⁵.

As dysphagia is the main symptom of this disease, current treatment modalities focus on alleviation of this symptom⁶ . Multiple methods exist for managing such a disease, including botulinum toxin injection, endoscopic balloon dilatation, surgical Heller cardiomyotomy with fundoplication, and peroral endoscopic myotomy .^7,8

Currently, laparoscopic Heller cardiomyotomy with anterior fundoplication is the most often used treatment for achalasia, as it can improve long-term outcomes in approximately 90% of patients^9,10. It entails mechanical disruption of oesophagal and gastric muscle fibres leading to enhanced oesophagal emptying and relief of dysphagia.¹¹

To obtain such an outcome, all muscle fibres should be divided with complete exposure of the underlying mucosa. ⁶ As a result, an intraoperative mucosal injury could occur during this procedure. In fact, multiple studies have reported that this dreadful complication is the most common complication during the myotomy procedure. ^12,14.

According to our extensive literature research, there are few publications dealing with the risk factors for mucosal injury during the Heller operation. Therefore, we conducted the present study to detect these possible risk factors and to elucidate their impact on operative and post-operative outcomes.

PATIENTS AND METHODS

After receiving approval from our medical school's local scientific committee, this retrospective investigation was carried out at the General Surgery Department of Al-Azhar University Hospitals. The study was designed for adult patients diagnosed with achalasia who underwent laparoscopic Heller cardiomyotomy at our department during the period between January 2015 and December 2021 (seven-years period). We excluded patients whose age below 18 years, who underwent the open Heller procedure, or who had recurrent achalasia after a primary Heller procedure were excluded from the current study.

Preoperative preparation included history taking, clinical examination in addition to the preoperative laboratory, radiological and endoscopic investigations. A barium meal examination was ordered for all cases as a preliminary investigation for dysphagia and to assess the shape of the oesophagus. The diagnosis of achalasia was confirmed via oesophagal manometry, which showed the classic findings of achalasia, including oesophagal aperistalsis, failure of oesophagal relaxation, and increased lower oesophagal sphincter pressure (LES). An upper gastrointestinal endoscopy was also ordered to exclude pseudoachalasia, especially in old patients. All patients received the same preoperative care, and informed consent was obtained from all of them after explaining the benefits, risks, and outcomes of the surgical intervention.

The procedure was performed via laparoscopy using the five-port technique. The camera port was inserted above the umbilicus, while the two working ports were inserted at the same level at the right and left midclavicular lines. An epigastric port was inserted for liver retraction, while the other one was inserted at the left anterior axillary line. The operation was started by dissection of the part flaccida and the phrenicoesophageal membrane till exposing the abdominal oesophagus, cardia and upper part of the stomach. Heller myotomy was done using either a harmonic scalpel or ligasure device. The length of the myotomy was 7 cm above the cardia and 3 cm below it. Saline was injected into the nasogastric tube present in the oesophagus to notice any leakage from the oesophagal or gastric mucosae. If leakage was detected, it was repaired using interrupted vicryl 4/0 sutures, and the leakage test was repeated. This was followed by Dor fundoplication over the myotomy part as a protective method against reflux. A surgical drain was inserted below the left lobe in most cases. All patients received the standard post-operative care, and most cases were allowed to start oral fluid intake on the first post-operative day unless a mucosal injury was encountered.

Based on the incidence of intraoperative mucosal injury, the included patients were divided into two groups; Group A included patients without perforation, and Group B included patients with perforation. The mucosal injury was established when a full-thickness perforation was detected either at the oesophagal side, gastric side, or esophagogastric junction. ⁶

Data collection included preoperative data (age, sex, body mass index BMI, smoking, comorbidities, symptoms, disease duration, previous balloon dilatation, oesophagal shape and LES pressure values), operative data (surgeon experience, operative time, and blood loss), and post-operative data (day of oral fluid intake, hospital stay, and mortality). Surgeon experience was classified according to their academic degree (A for the professor, B for assistant professor, and C for lecturer).

Statistical analysis

SPSS version 26 for Windows® was used to code, process, and analyse the data. The qualitative data was given as a number (frequency) and a percentage. The Chi-Square test was used to compare groups. The non-parametric data were expressed as median and range, whereas the parametric data were expressed as mean and SD. The student's t-test was used to compare two groups with normally distributed quantitative variables, and the Mann-Whitney U-test was employed if the data were abnormally distributed. To identify dependent and independent risk factors, researchers utilised regression analyses (univariate and multivariate). For all the applied tests, a p-value less than 0.05 was considered significant.

RESULTS

In our retrospective series, the intraoperative mucosal injury was detected in nine patients, with an incidence of 17.31%. The included participants were divided into Group A (43 cases without perforation) and Group B (nine cases with perforation).

When comparing the two study groups, group B had significantly older ages compared to Group A (50.11 vs 40.91 years respectively – p < 0.001). Nevertheless, gender distribution and BMI were statistically comparable between the two groups. Furthermore, there was no significant difference in the prevalence of smoking or other medical comorbidities between our two groups.

The duration of the disease ranged between two and seven years in both groups.  Dysphagia was the most common presentation, followed by regurgitation and chest pain. All of the previous symptoms showed no significant difference between the two groups (p > 0.05). However, previous balloon dilatation was reported by 6.98% and 88.89% of patients in Groups A and B, respectively, with a significant increase in association with mucosal injury (p < 0.001).

Preoperative investigations, including barium swallow findings and LES pressure, were not significantly different between the two groups. The previous data are shown in Table 1.

The duration of operation showed a significant prolongation in Group B (87.78 vs 73.79 minutes in Group A - p < 0.001). Moreover, Group B showed a significant increase in the amount of intraoperative blood loss (67.67 vs 29.19 ml in Group A – p < 0.001). Regarding surgeon experience, it was evident that lower experience was associated with an increased risk of mucosal injury (p = 0.016). Table (2) shows the previous data.

Both the day of oral fluid intake and duration of hospitalization were significantly increased in patients with mucosal injury (p < 0.001), as shown in Table 3. No mortality was encountered in the current study.

Old age, previous balloon dilatation and low surgeon experience were significant risk factors for mucosal injury on univariate analysis. Only previous balloon dilatation maintained its significance on the multivariate one (Table 4).

Table 1: Preoperative data.

Table 2: Operative data.

Table 3: Post-operative data.

Table 4: Regression analysis to detect predictors of mucosal injury during the Heller procedure.