Pressor and depressor responses in thermocoagulation of the trigeminal ganglion

The Trigeminocardiac Reflex During the Anterior Transpetrosal Approach

OBJECTIVE

The anterior transpetrosal approach (ATPA), during which the trigeminal nerve (TN) is manipulated, has a risk of eliciting the trigeminocardiac reflex (TCR). The aim of this study was to assess the risk of TCR during ATPA.

METHODS

Surgical records of 92 patients who had surgical treatment via ATPA at the Keio University Hospital between December 2005 and June 2015 were retrospectively analyzed. Patients were divided into 2 groups on the basis of the occurrence of TCR during surgery, and clinical and tumor characteristics were compared. Tumor characteristics were evaluated based on preoperative images and intraoperative findings and included the side of the lesion, size of the lesion, tumor size in Meckel cave, pathology of the disease, cavernous sinus invasion, extension into Meckel cave, and adhesion of lesion to TN.

RESULTS

TCR was observed in 14 of 92 patients (15.2%). TCR occurrence was significantly related to Meckel cave tumor size (P = 0.0264) and adhesion of the lesion to TN (P = 0.0002).

CONCLUSIONS

This study suggests that TCR is related to Meckel cave tumor size and tumor adhesion to TN in ATPA. To our knowledge, this is the first report describing TCR during ATPA.

Trigemino-cardiac reflex during orbital floor reconstruction: a case report and review

Trigemino-cardiac reflex is occurrence of hypotension and bradycardia upon surgical manipulation of areas supplied by the trigeminal nerve, and has been reported during craniofacial maxillofacial and ocular surgeries. Communication between the anaesthetic and surgical team is essential, and cessation of the precipitating stimulus is the first and most important therapeutic step. We report a case of immediate, reproducible, and reflexive response of Bradycardia and dysrhythmia upon manipulation of orbital fracture during orbital floor reconstruction in a 65-year-old man. Upon recognition of the reproducible relationship between falcine stimulation and increased vagal tone, the patient was given atropine in an effort to block cholinergic hyperactivity. After atropine administration, no further dysrhythmias occurred and surgery was carried uneventfully.

Perioperative and long-term operative outcomes after surgery for trigeminal neuralgia: microvascular decompression vs percutaneous balloon ablation

Objectives

Numerous medical and surgical therapies have been utilized to treat the symptoms of trigeminal neuralgia (TN). This retrospective study compares patients undergoing either microvascular decompression or balloon ablation of the trigeminal ganglion and determines which produces the best long-term outcomes.

Methods

A 10-year retrospective chart review was performed on patients who underwent microvascular decompression (MVD) or percutaneous balloon ablation (BA) surgery for TN. Demographic data, intraoperative variables, length of hospitalization and symptom improvement were assessed along with complications and recurrences of symptoms after surgery. Appropriate statistical comparisons were utilized to assess differences between the two surgical techniques.

Results

MVD patients were younger but were otherwise similar to BA patients. Intraoperatively, twice as many BA patients developed bradycardia compared to MVD patients. 75% of BA patients with bradycardia had an improvement of symptoms. Hospital stay was shorter in BA patients but overall improvement of symptoms was better with MVD. Postoperative complication rates were similar (21% vs 26%) between the BA and MVD groups.

Discussion

MVD produced better overall outcomes compared to BA and may be the procedure of choice for surgery to treat TN.

The impact of hypotension due to the trigeminocardiac reflex on auditory function in vestibular schwannoma surgery

Object

Surgical manipulation of the fifth cranial nerve during its intra- or extracranial course may lead to bradycardia or even asystole as well as arterial hypotension, a phenomenon described as the trigeminocardiac reflex (TCR). The authors studied the impact of this reflex on postoperative auditory function in patients undergoing vestibular schwannoma (VS) surgery.

Methods

One hundred patients scheduled for VS surgery were studied prospectively for parameters influencing the postoperative auditory function. The evaluation included sex, age, pre- and postoperative auditory function, preoperative mean arterial blood pressure, preoperative medical diseases or medication (for example, antiarrhythmia drugs), tumor size and localization, and the intraoperative occurrence of the TCR.

The TCR, which occurred in 11% of the patients, influenced the postoperative hearing function in the patients with Hannover Class T3 and T4 VSs.

With an overall hearing preservation of 47%, 11.1% of the patients in the TCR group and 51.4% of those in the non-TCR group experienced preserved hearing function postoperatively. In cases involving larger tumors (Hannover Class T3 and T4), an intraoperative TCR was associated with a significantly worse postoperative hearing function during VS surgery (p = 0.005).

Conclusions

The hypotension following TCR is a negative prognostic factor for hearing preservation in patients undergoing VS surgery. Patients’ knowledge of this can be increased pre- and postoperatively. Further study of this phenomenon will advance the understanding of the underlying mechanisms and may help to improve hearing preservation by controlling the occurrence of the TCR.