Vagus nerve injury symptoms after catheter ablation for atrial fibrillation

Editorial to "Incidence of nausea/vomiting following propofol sedation with adaptive-servo ventilation for atrial fibrillation ablation"

The incidence of nausea, vomiting, and symptoms relating to vagal nerve injury remains high after atrial fibrillation ablation, with many patients reporting symptoms in the hours to months after their procedure. These are often underreported in literature, and this editorial piece opines about a study assessing this in detail.

Symptomatic periesophageal vagal nerve injury by different energy sources during atrial fibrillation ablation

Background

Symptomatic gastric hypomotility (SGH) is a rare but major complication of atrial fibrillation (AF) ablation, but data on this are scarce.

Objective

We compared the clinical course of SGH occurring with different energy sources.

Methods

This multicenter study retrospectively collected the characteristics and clinical outcomes of patients with SGH after AF ablation.

Results

The data of 93 patients (67.0 ± 11.2 years, 68 men, 52 paroxysmal AF) with SGH after AF ablation were collected from 23 cardiovascular centers. Left atrial (LA) ablation sets included pulmonary vein isolation (PVI) alone, a PVI plus a roof-line, and an LA posterior wall isolation in 42 (45.2%), 11 (11.8%), and 40 (43.0%) patients, respectively. LA ablation was performed by radiofrequency ablation, cryoballoon ablation, or both in 38 (40.8%), 38 (40.8%), and 17 (18.3%) patients, respectively. SGH diagnoses were confirmed at 2 (1-4) days post-procedure, and 28 (30.1%) patients required re-hospitalizations. Fasting was required in 81 (92.0%) patients for 4 (2.5-5) days; the total hospitalization duration was 11 [7-19.8] days. After conservative treatment, symptoms disappeared in 22.3% of patients at 1 month, 48.9% at 2 months, 57.6% at 3 months, 84.6% at 6 months, and 89.7% at 12 months, however, one patient required surgery after radiofrequency ablation. Symptoms persisted for >1-year post-procedure in 7 patients. The outcomes were similar regardless of the energy source and LA lesion set.

Conclusions

The clinical course of SGH was similar regardless of the energy source. The diagnosis was often delayed, and most recovered within 6 months, yet could persist for over 1 year in 10%.

Incidence and clinical relevance of upper gastrointestinal pathology during preprocedural endoscopy in patients undergoing pulmonary vein isolation

BACKGROUND

Reflux-induced esophagitis might facilitate ablation-induced esophageal lesions (ELs) following pulmonary vein isolation (PVI), and these may progress to atrio-esophageal fistula (AEF). In contrast, preexisting ELs are not prone to progression but may affect procedure planning.

OBJECTIVE

To study the incidence of preexisting esophageal and upper gastrointestinal (UGI) pathology in patients undergoing PVI, and the relation to ablation-induced ELs.

METHODS

From 08/2018 to 09/2021, consecutive patients undergoing (radiofrequency [RF] or cryoballoon [CB]) PVI were examined by esophagogastroscopy (EGD) before and following ablation. Postprocedural endoscopic ultrasound (EUS) was added in 2021.

RESULTS

412 patients (median age 67.5 [IQR 61.3-75.0] years, 56.1% male) were studied. Preprocedural EGD showed abnormalities in 226/399 patients, 15% in the lower third of the esophagus. Half (99/226) were relevant for PVI, 13 procedures were postponed, 6 due to pathological EGD results. A third of the patients with new esophageal injury following ablation had preexisting esophagitis which was associated with a trend for a higher incidence of ELs after RF ablation (12.5 vs. 6.9%, p = 0.232), and a six- and two-fold higher rate of food retention after CB-PVI (28.6 vs. 4.5%, p = 0.008) and RF ablation (8.3 vs. 4.4%, p = 0.279), respectively.

CONCLUSION

(1) EGD before PVI showed UGI abnormalities in > 50% of patients, one-fourth of these relevant for PVI. (2) Esophageal inflammation was associated with a higher incidence of post-ablation (peri)-esophageal injury. Whether having this information before ablation is able to reduce ELs or AEF remains to be shown.

The Wandering Nerve: Positional Variations of the Cervical Vagus Nerve and Neurosurgical Implications

BACKGROUND

The vagus ("wandering") nerve is the longest cranial nerve with the largest territory of innervation in the human body. Injury during various operative procedures involving the anterior or lateral neck may lead to serious complications. Per "textbook" descriptions, the cervical vagus nerve (CVN) commonly locates within the carotid sheath, in between the common carotid artery (CCA) and internal jugular vein (IJV). However, anatomic variations in its positioning may occur more often than expected and intraoperative identification may anticipate potential surgical pitfalls.

METHODS

A literature review was conducted per PRISMA guidelines for all studies describing positional variations of the CVN within the carotid sheath. A rare and potentially dangerous variation, occurring in only 0.7% of all reported cases, is illustrated with a cadaveric case.

RESULTS

Overall, 10 anatomic CVN variations have been described across 971 specimens. The non-textbook variations (26.5%) consist of: lateral (4.7%), anterolateral (8.7%), posteromedial (0.2%), posterior (5.8%), anterior (3.1%), medial (0.7%), and anteromedial (0.4%) to the CCA, as well as posterolateral (0.3%) and posterior (2.6%) to IJV. The "textbook" anatomic location is posterolateral to CCA (73.5%). Moreover, an increase in variability is reported on the left side (17.1%) compared with the right (11.3%). Our cadaveric dissection revealed a right-sided CVN directly medial to the CCA.

CONCLUSIONS

Positional variations of the CVN occur in over 26% of patients and may add difficulty to an array of surgical procedures. Knowledge of these variations and their prevalence may aid the surgeon in conducting a more precise dissection possibly preventing significant potential adverse sequelae.

Use of Light Sensor and Focused Local Atrial Electrogram Recordings for the Monitoring of Thermal Injury to the Esophagus and Lungs During Laser Catheter Ablation of the Posterior Atrial Walls: Preclinical In Vitro Porcine and In Vivo Canine Experimental Studies

During the catheter ablation of atrial fibrillation, thermal damages to the esophagus may have deleterious effects. The use of the SensoLas light sensor (SLLS; LasCor GmbH, Taufkirchen, Germany) and focused local atrial electrograms (LEGs) were tested as means for the assessment of thermal effects on the esophagus during laser catheter ablation. A total of 32 transcatheter in vitro and in vivo 1064-nm laser impacts were aimed at porcine (n = 16) and canine (n = 16) atrial endocardia. Photons scattering through the atrial and esophageal walls were captured by the SLLS, transmitted via an optical fiber to a diode, and converted to power displayed on a monitor. The laser was stopped automatically when the power measurement reached values beyond the preset upper limit. During in vivo laser applications, bipolar LEGs were recorded via the miniature electrodes of the laser catheter. Thermal damage to the esophagus was avoided when the power measurement was limited to 150 μW or less and the diode current was 60 μA or less, regardless of the energy setting used and regardless of the thicknesses of the atrial and esophageal walls. Laser energy applied for eight seconds to 13 seconds (average: 10 seconds) abolished the electrical potentials permanently. In conclusion, the control of laser light via the SLLS and of atrial potential amplitudes in the LEGs can prevent thermal esophageal and lung injury during laser catheter ablation.

Vagal schwannomas of the head and neck: A comprehensive review and a novel approach to preserving vocal cord innervation and function

BACKGROUND

Schwannomas, benign tumors arising from neurolemmocytes, are the most common type of peripheral nerve tumors. Extracranial schwannomas are most often found in the parapharyngeal space, commonly involving the vagus nerve to cervical sympathetic trunk. Vagal schwannomas present several unique clinical and therapeutic challenges.

METHODS

A comprehensive literature review was conducted on 197 articles reporting 235 cases of cervical vagal schwannomas. Presenting symptoms, treatment approach, and postoperative outcomes were recorded and analyzed.

RESULTS

Vagal schwannomas commonly present as asymptomatic neck masses. When they become symptomatic, surgical resection is the standard of care. Gross total resection is associated with higher postoperative morbidity compared to subtotal resection. Initial reports using intraoperative nerve monitoring have shown improved nerve preservation. Recurrence rates are low.

CONCLUSION

The combination of intermittent nerve mapping with novel continuous vagal nerve monitoring techniques may reduce postoperative morbidity and could represent the future standard of care for vagal schwannoma treatment.