Trigeminal neuralgia caused by compression from petrosal vein transfixing the nerve

Sacrifice or preserve the superior petrosal vein in microvascular decompression surgery: a systematic review and meta-analysis

OBJECTIVE

In microvascular decompression (MVD) surgery through the retrosigmoid approach, the surgeon may have to sacrifice the superior petrosal vein (SPV). However, this is a controversial maneuver. To date, high-level evidence comparing the operative outcomes of patients who underwent MVD with and without SPV sacrifice is lacking. Therefore, this study sought to bridge this gap.

METHODS

The authors searched the Medline and PubMed databases with appropriate Medical Subject Heading (MeSH) terms and keywords. The primary outcome was vascular-related complications; secondary outcomes were new neurological deficit, cerebrospinal fluid (CSF) leak, and neuralgia relief. The pooled proportions of outcomes and OR (95% CI) for categorical data were calculated by using the logit transformation and Mantel-Haenszel methods, respectively.

RESULTS

Six studies yielding 1143 patients were included, of which 618 patients had their SPV sacrificed. The pooled proportion (95% CI) values were 3.82 (0.87-15.17) for vascular-related complications, 3.64 (1.0-12.42) for new neurological deficits, 2.85 (1.21-6.58) for CSF leaks, and 88.90 (84.90-91.94) for neuralgia relief. The meta-analysis concluded that, whether the surgeon sacrificed or preserved the SPV, the odds were similar for vascular-related complications (2.5% vs 1.5%, OR [95% CI] 1.01 [0.33-3.09], p = 0.99), new neurological deficits (1.2% vs 2.8%, OR [95% CI] 0.55 [0.18-1.66], p = 0.29), CSF leak (3.1% vs 2.1%, OR [95% CI] 1.16 [0.46-2.94], p = 0.75), and neuralgia relief (86.6% vs 87%, OR [95% CI] 0.96 [0.62-1.49], p = 0.84).

CONCLUSIONS

SPV sacrifice is as safe as SPV preservation. The authors recommend intentional SPV sacrifice when gentle retraction fails to enhance surgical field visualization and if the surgeon encounters SPV-related neurovascular conflict and/or anticipates impeding SPV-related bleeding.

Microvascular decompression for pediatric onset trigeminal neuralgia: patterns and variation

OBJECTIVES

Pediatric trigeminal neuralgia has been rarely reported in the literature, which were only 28 cases. Although microvascular decompression (MVD) has been widely accepted as effective therapy for trigeminal neuralgia, the etiology and surgical treatment of pediatric ones are seldom addressed. We report our experience with MVD for pediatric trigeminal neuralgia patients with emphasis on the vascular conflict patterns and surgical skills.

METHODS

This retrospective report included 11 pediatric TN patients, who underwent MVD and were followed for 3-86 months. The data were retrospectively analyzed with emphasis on the clinical features.

RESULTS

This series included 4 boys and 7 girls with average age of 13 ± 3.4 years old, their onset age were from 7 to 18 years old. The singular vein and combined artery/vein conflictions account for 7/11. 9 (81.8%) patients achieved immediate excellent outcomes. One recurrence was observed after 5 months and refused the second surgery.

CONCLUSIONS

The etiology of pediatric onset trigeminal neuralgia is still vascular conflict, whose patterns are different from adults, of which combined artery/vein and singular venous compression patterns have a much more higher proportion. Because of the smaller operative space and fragile-thin venous wall with adhesion to other structures, it is much more difficult to decompress the trigeminal nerve among pediatric patients. Sufficient arachnoid release, full exploration, and decompression along the trigeminal nerve were necessary, which will increase the excellent rate among pediatric patients.

Microvascular Decompression for Trigeminal Neuralgia Caused by Venous Offending on the Ventral Side of the Root Entrance/Exit Zone: Classification and Management Strategy

Background

Trigeminal neuralgia (TGN) is typically caused by an offending artery (OA) but may also involve an offending vein. Venous offending on the ventral side of the root entrance/exit zone (VO-VREZ) is particularly challenging.

Objective

To analyze the rate and pattern of VO-VREZ and propose management strategy accordingly.

Methods

VO-VREZ was classified into 3 types based on its anatomical relationship with a nerve root (A, the vein was covered by the nerve root entirely; B, the vein was lateral to the nerve root; and C, the vein penetrated the nerve root) and 3 groups based on the absence/presence of offending artery (I, no OA; II, suspected OA; and III, definitive OA).

Results

The analysis included 143 cases with complete follow-up. Type A, B, and C accounted for 11.9, 31.5, and 56.6% of the cases, respectively. Group I, II, and III accounted for 24.5, 26.6, and 49.0%, respectively. Most group I VO-VREZ cases (26 out of 31) were managed with coagulation followed by division. Most group II VO-VREZ cases (31 out of 38) were decompressed with shredded Teflon interposition. Group III VO-VREZ was left in place in all 70 cases. Immediate pain relief was achieved in all cases. Temporary hemifacial hypesthesia occurred in 21 patients (14.7%), among which 14 were managed with Teflon decompression. Within the 4.5-year median follow-up, pain recurred in 11 patients (7.7%), but all with lesser intensity.

Conclusion

VO-VREZ is not uncommon in patients with TGN. Different management strategy should be chosen according to the anatomical feature and the absence/presence of arterial conflict.

Vein-related Trigeminal Neuralgia: How to Determine the Treatment Method of the Causative Vein: A Technical Note

Trigeminal neuralgia (TN) is often caused by various vein forms. Herein, we report two cases of vein-related TN. In the first case, the vein of the cerebellopontine fissure (VCPF), along with the thickened surrounding arachnoid, clung to the trigeminal nerve. As the perfusion range of this vein was expected to be wide and its injury might cause extensive venous infarction, the anchor between the trigeminal nerve and the vein was carefully dissected and the vein was successfully transposed. In the second case, the involvement of the vein of the middle cerebellar peduncle (VMCP), which penetrates the nerve bundle of the trigeminal nerve, was suspected. Because vein transposition was impossible, the vein was transected at the nerve penetration site after confirming that there was sufficient collateral venous outflow. The superior petrosal vein and its tributaries are the primary causative veins of vein-related TN, and their contact patterns are infinite. Moreover, their perfusion range and the presence or absence of collateral venous outflow vary from case to case. Therefore, it is necessary to judge the perfusion range as well as collateral venous outflow based on preoperative images and intraoperative findings and to determine the appropriate treatment method for each case.

Classification of the superior petrosal veins and sinus based on drainage pattern

BACKGROUND

The increasing number of reports of complications after sacrificing the superior petrosal veins, the largest veins in the posterior fossa, has led to a need for an increased understanding of the anatomy of these veins and the superior petrosal sinus into which they empty.

OBJECTIVE

To examine the anatomy of the superior petrosal veins and their size, draining area, and tributaries, as well as the anatomic variations of the superior petrosal sinus.

METHOD

Injected cadaveric cerebellopontine angles and 3-dimensional multifusion angiography images were examined.

RESULTS

The 4 groups of the superior petrosal veins based on their tributaries, course, and draining areas are the petrosal, posterior mesencephalic, anterior pontomesencephalic, and tentorial groups. The largest group was the petrosal group. Its largest tributary, the vein of the cerebellopontine fissure, was usually identifiable in the suprafloccular cistern located above the flocculus on the lateral surface of the middle cerebellar peduncle. The medial or lateral segment of the superior petrosal sinus was absent in 40% of cerebellopontine angles studied with venography.

CONCLUSION

The superior petrosal veins and their largest tributaries, especially the vein of the cerebellopontine fissure, should be preserved if possible. Obliteration of superior petrosal sinuses in which either the lateral or medial portion is absent may result in loss of the drainage pathway of the superior petrosal veins. Preoperative assessment of the superior petrosal sinus should be considered before transpetrosal surgery in which the superior petrosal sinus may be obliterated.

Management of intraneural vessels during microvascular decompression surgery for trigeminal neuralgia

OBJECTIVE

To present the authors' experience in surgical treatment of patients with trigeminal neuralgia (TN) with intraneural vessels.

METHODS

The study included three patients with TN and an intraneural artery (superior cerebellar artery) and eight patients with TN and an intraneural vein. The patients underwent microvascular decompression (MVD) procedures. The intraneural arteries were wrapped by a thin piece of Teflon sponge. The intraneural veins all were coagulated and divided. Clinical outcomes and postoperative complications were analyzed.

RESULTS

Eight patients were free of facial pain soon after surgery, achieving excellent outcomes; two patients had good outcomes; and one patient had a failed first operation but experienced pain relief after reoperation, achieving an excellent outcome. Three patients had postoperative facial numbness because the trigeminal nerves were impaired owing to coagulation or mechanical injury. However, no dense corneal numbness or loss of corneal reflex occurred.

CONCLUSIONS

If the intraneural vessel is an artery, it can be decompressed by wrapping techniques. Otherwise, intraneural veins should be coagulated and divided. Most patients can achieve excellent or good pain relief with this approach; facial numbness is uncommon.

Clinical features and surgical treatment of trigeminal neuralgia caused solely by venous compression

PURPOSE

To summarize our experience and lessons of microvascular decompression surgery for trigeminal neuralgia caused solely by venous compression.

METHODS

Fifteen patients with idiopathic trigeminal neuralgia caused by venous compression only underwent microvascular decompression. The entire course of the trigeminal root was explored thoroughly; and coagulating and cutting techniques were preferred in decompressing the culprit veins. Their clinical features, outcomes and operative complications were analyzed.

RESULTS

The compressing veins included the transverse pontine vein in five cases (33.3%), the transverse pontine vein and the vein of middle cerebellar peduncle in one (6.7%), the transverse pontine vein and the vein of cerebellopontine fissure in one (6.7%), the superior petrosal vein in three (20%), the pontotrigeminal vein in one (6.7%), the vein of the cerebellopontine fissure in two (13.3%), and the plexus venosus or venule in two (13.3%). After microvascular decompression, 11 cases (73.3%) had "excellent" or "good" pain relief. Four cases (26.7%) failed the first surgery; and two of them underwent re-operation and got "excellent" pain relief. Postoperative facial numbness appeared in four cases, due to injury to trigeminal nerve when coagulation.

CONCLUSION

The transverse pontine vein is the most common offending vein. For this type of trigeminal neuralgia, coagulating and cutting techniques are preferred in decompressing the culprit veins. The entire course of the trigeminal root should be explored and decompressed. Following these principles, excellent or good pain relief could be achieved in most cases; and recurrence is rare. However, sometimes injury to the nerve is unavoidable when coagulating the culprit vein.

Localized venous plexi in the spine simulating prolapse of an intervertebral disc: a report of six cases

STUDY DESIGN

Six cases are reported in which the clinical presentation of a prolapsed intervertebral disc was found to be caused by a localized venous plexus.

OBJECTIVES

To emphasize the fact that the clinical presentation of a localized plexus of epidural veins in the lumbar spine can resemble that of an acute disc prolapse.

SUMMARY OF BACKGROUND DATA

The finding of enlarged epidural veins during lumbar disc decompression is relatively common, but it is only recently that they have been implicated as the cause of the presenting symptoms.

METHODS AND RESULTS

Six individuals presented with severe pain in the lower back accompanied by sciatica, which had begun acutely. Physical examination in most of these patients showed the presence of neurologic signs in the affected leg. The initial clinical assessment was that of an acute prolapse of a lumbar disc. This diagnosis appeared to be borne out by the MRI scans, which demonstrated a "prolapsed disc" at the relevant level of the spine. However, at surgery, the intervertebral disc appeared to be relatively normal, but at the spine was found a large, localized plexus of epidural veins whose configuration matched the MRI image. The symptoms were relieved by decompression of the spine and ablation of the veins.

CONCLUSIONS

Any pathologic process in the lumbar spine compressing a nerve root can cause localized pain in the back accompanied by sciatica. Most of these conditions can be differentiated by means of an MRI scan. The MRI image of a localized plexus of epidural veins, however, closely resembles that of a prolapsed intervertebral disc, which may be diagnostically misleading.