Incidence and predictors of thermal oesophageal and vagus nerve injuries in Ablation Index-guided high-power-short-duration ablation of atrial fibrillation: a prospective study

AIMS

High-power-short-duration (HPSD) ablation is an effective treatment for atrial fibrillation but poses risks of thermal injuries to the oesophagus and vagus nerve. This study aims to investigate incidence and predictors of thermal injuries, employing machine learning.

METHODS AND RESULTS

A prospective observational study was conducted at Leipzig Heart Centre, Germany, excluding patients with multiple prior ablations. All patients received Ablation Index-guided HPSD ablation and subsequent oesophagogastroduodenoscopy. A machine learning algorithm categorized ablation points by atrial location and analysed ablation data, including Ablation Index, focusing on the posterior wall. The study is registered in clinicaltrials.gov (NCT05709756). Between February 2021 and August 2023, 238 patients were enrolled, of whom 18 (7.6%; nine oesophagus, eight vagus nerve, one both) developed thermal injuries, including eight oesophageal erythemata, two ulcers, and no fistula. Higher mean force (15.8 ± 3.9 g vs. 13.6 ± 3.9 g, P = 0.022), ablation point quantity (61.50 ± 20.45 vs. 48.16 ± 19.60, P = 0.007), and total and maximum Ablation Index (24 114 ± 8765 vs. 18 894 ± 7863, P = 0.008; 499 ± 95 vs. 473 ± 44, P = 0.04, respectively) at the posterior wall, but not oesophagus location, correlated significantly with thermal injury occurrence. Patients with thermal injuries had significantly lower distances between left atrium and oesophagus (3.0 ± 1.5 mm vs. 4.4 ± 2.1 mm, P = 0.012) and smaller atrial surface areas (24.9 ± 6.5 cm2 vs. 29.5 ± 7.5 cm2, P = 0.032).

CONCLUSION

The low thermal lesion's rate (7.6%) during Ablation Index-guided HPSD ablation for atrial fibrillation is noteworthy. Machine learning based ablation data analysis identified several potential predictors of thermal injuries. The correlation between machine learning output and injury development suggests the potential for a clinical tool to enhance procedural safety.

Transient postsurgical gastroparesis is accompanied by reversible changes of the cervical vagus nerve's morphology after neck dissection - an ultrasound study

AIMS

During neck dissection (ND), the vagus nerve (VN) may be exposed to manipulation together with common carotid artery and internal jugular vein. The postsurgical gastroparesis was previous related to the VN injury. The aim of our study was to evaluate by ultrasound the VN changes in patients with unilateral and bilateral ND and to establish if there is a relationship between postoperative findings of VN and postsurgical gastroparesis.

MATERIAL AND METHODS

Seventeen patients in which 30 ND (4 unilateral and 13 bilateral) were performed, were enrolled in the study. The VN's area and diameter were measured preoperative (baseline), one week (T1) and one month (T2) postoperative. Gastrointestinal symptoms were evaluated at T1 and T2 phases using the patient assessment of the upper gastrointestinal symptom severity index (PAGI-SYM).

RESULTS

There was a statistical difference between area and diameters of VN between T1 and baseline (p<0.001), and T1 and T2 phases (p<0.001), respectively. No statistical differences were detected at baseline and T2 phases in areas (p=0.934) and diameters (p>0.999). Gastrointestinal symptoms, found at the T1 phase regressed at T2 phase, were correlated with VN area and diameter changes (p<0.001).

CONCLUSIONS

VN ultrasound clearly showed the transient dimensional changes of VN caused by manipulation in ND, which may lead to temporary gastrointestinal symptoms due to reversible dysfunction of VN.

Roux‑en‑Y gastric bypass surgery triggers rapid DNA fragmentation in vagal afferent neurons in rats

Previous studies have shown that Roux‑en‑Y gastric bypass (RYGB), one of the most effective weight loss treatments for obesity, results in neurodegenerative responses in vagal afferent gut‑brain connection reflected by microglia activation and reduced sensory input to the nucleus tractus solitarius (NTS). However, it is not known whether RYGB‑induced microglia activation is the cause or an effect of the reported neuronal damage. Therefore, the aim of this study was to establish the order of neurodegenerative responses in vagal afferents after RYGB in the nodose ganglia (NG) and NTS in male and female rats. Sprague‑Dawley rats were fed regular chow or an energy‑dense diet for two weeks followed by RYGB or sham surgery. Twenty‑four hours later, animals were sacrificed and NG and NTS were collected. Neuronal cell damage was determined by TUNEL assay. Microglia activation was determined by quantifying the fluorescent staining against the ionizing calcium adapter‑binding molecule 1. Reorganization of vagal afferents was evaluated by fluorescent staining against isolectin 4. Results of the study revealed significantly increased DNA fragmentation in vagal neurons in the NG when observed at 24 h after RYGB. The surgery did not produce rapid changes in the density of vagal afferents and microglia activation in the NTS. These data indicate that decreased density of vagal afferents and increased microglia activation in the NTS likely ensue as a res ult of RYGB‑induced neuronal damage.

[Vagus and hypoglossus palsy after nasotracheal intubation and throat packing]

Ipsilateral extracranial palsy of the hypoglossus and vagus nerve is a rare complication of intubation. This is a case report of a 50-year-old male with unilateral palsy of the hypoglossus and vagus nerve after reoperation for a mandibular fracture. The patient underwent logopaedic treatment, and ten months after the operation there was significant but not complete remission of symptoms. Videostroboscopy revealed near-normalisation of vocal cord movement.

[Value of endoscopy application in the management of complications after radical gastrectomy for gastric cancer]

Endoscopy plays an important role in the diagnosis and treatment of postoperative complications of gastric cancer. Endoscopic intervention can avoid the second operation and has attracted wide attention. Early gastric anastomotic bleeding after gastrectomy is the most common. With the development of technology, emergency endoscopy and endoscopic hemostasis provide a new treatment approach. According to the specific circumstances, endoscopists can choose metal clamp to stop bleeding, electrocoagulation hemostasis, local injection of epinephrine or sclerotherapy agents, and spraying specific hemostatic agents. Anastomotic fistula is a serious postoperative complication. In addition to endoscopically placing the small intestine nutrition tube for early enteral nutrition support treatment, endoscopic treatment, including stent, metal clip, OTSC, and Over-stitch suture system, can be chosen to close fistula. For anastomotic obstruction or stricture, endoscopic balloon or probe expansion and stent placement can be chosen. For esophageal anastomotic intractable obstruction after gastroesophageal surgery, radial incision of obstruction by the hook knife or IT knife, a new method named ERI, is a good choice. Bile leakage caused by bile duct injury can be treated by placing the stent or nasal bile duct. In addition, endoscopic methods are widely used as follows: abdominal abscess can be treated by the direct intervention under endoscopy; adhesive ileus can be treated by placing the catheter under the guidance of endoscopy to attract pressure; alkaline reflux gastritis can be rapidly diagnosed by endoscopy; gastric outlet obstruction mainly caused by cancer recurrence can be relieved by metal stent placement and the combination of endoscopy and X-ray can increase success rate; pyloric dysfunction and spasm caused by the vagus nerve injury during proximal gastrectomy can be treated by endoscopic pyloromyotomy, a new method named G-POEM, and the short-term outcomes are significant. Endoscopic submucosal dissection (ESD) allows complete resection of residual gastric precancerous lesions, however it should be performed by the experienced endoscopists.

[Esophago-gastric complications after ablation in atrial fibrillation]

Atrial-esophageal fistula (AOF) after ablation in atrial fibrillation has a fatal outcome. Fully documented in 2004, AOF has never completely disappeared despite technological evolvements. Survival depends on early recognition and treatment. Gastroscopy allows early detection of esophageal lesions. We summarize here AOF mechanisms, evoking symptoms and treatment ; contribution of gastroscopy in early detection ; and finally symptoms from vagal and phrenic nerve injuries. This information is useful for emergency doctors, gastroenterologists / endoscopists, and general practitioners.

Periesophageal vagal plexus injury is a favorable outcome predictor after catheter ablation of atrial fibrillation

BACKGROUND

Collateral damage to periesophageal vagal plexus associated with symptomatic gastric hypomotility and associated symptoms are not uncommon after catheter ablation of atrial fibrillation (AF). The injury may indicate transmural ablation lesions.

OBJECTIVE

The purpose of this study was to evaluate the periesophageal vagal plexus injury (PNI) and long-term outcome after catheter ablation of AF.

METHODS

A total of 441 consecutive patients with AF (mean age 54.71 ± 10.52 years; 134 women) who underwent catheter ablation (paroxysmal AF, n = 312; persistent AF, n = 129) were retrospectively enrolled from 2011 to 2013; group 1 was defined as patients with PNI and associated symptoms (n = 88), and group 2 was defined as patients without PNI or associated symptoms (n = 353). Baseline characteristics and electrophysiological properties were collected to analyze the relationship between PNI and clinical outcome. The association of AF recurrence after catheter ablation and PNI symptoms was also investigated.

RESULTS

During a mean follow-up period of 37.3 ± 0.94 months, group 1 had longer AF-freedom days in sinus rhythm after AF ablation and had less recurrence after the blanking period compared with group 2 (mean recurrence days, 1254.22 ± 45.26 days vs 1065.21 ± 33.35 days; P < .01). Multivariate analysis also revealed that PNI was an independently protective predictor of AF recurrence (hazard ratio 0.527; 95% confidence interval 0.289-0.959; P = .036). There was no difference in baseline characteristics, CHA2DS2-VASc score, or echocardiography follow-up duration.

CONCLUSION

PNI and associated symptoms are not uncommon after catheter ablation of AF. A better long-term outcome is thereby independently predicted, suggesting transmural ablation lesions during pulmonary vein isolation.