Management of veins during microvascular decompression for idiopathic trigeminal neuralgia

Meningitis after elective intracranial surgery: a systematic review and meta-analysis of prevalence

Meningitis is a potential complication of elective intracranial surgery (EIS). The prevalence of meningitis after EIS varies greatly in the literature. The objective of this study was to estimate the overall pooled prevalence of meningitis following EIS. Four databases (PubMed, Scopus, Web of Science, and Embase) were searched to identify relevant studies. Meta-analyses of proportions were used to combine data. Cochran's Q and I² statistics were used to assess and quantify heterogeneity. Additionally, several subgroup analyses were conducted to investigate the source of heterogeneity and examine differences in the prevalence based on variables such as geographical regions, income level, and meningitis type. The meta-analysis included 83 studies (30 959 patients) from 26 countries. The overall pooled prevalence of meningitis after EIS was 1.6% (95% CI 1.1-2.1), with high heterogeneity present (I² = 88%). The pooled prevalence in low- to middle-income countries and high-income countries was 2.7% (95% CI 1.6-4.1) and 1.2% (95% CI 0.8-1.7), respectively. Studies that reported only aseptic meningitis had a pooled prevalence of 3.2% (95% CI 1.3-5.8). The pooled prevalence was 2.8% (95% CI 1.5-4.5) in studies that reported only bacterial meningitis. Similar prevalence rates of meningitis were observed in the subgroups of tumor resection, microvascular decompression, and aneurysm clipping. Meningitis is a rare but not exceptional complication following EIS, with an estimated prevalence of 1.6%.

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.

Modified Transpetrosal-Transtentorial Approach for Resection of Large and Giant Petroclival Meningioma: Technical Nuance and Surgical Experiences

BACKGROUND

 Meningiomas arising from the petroclival area remain a challenge for neurosurgeons. Various approaches have been proposed to achieve maximum resection with minimal morbidity and mortality. Also, some articles correlated preservation of adjacent veins with less neurologic deficits.

OBJECTIVE

 To describe the experiences in using a new technique to achieve maximal resection of petroclival meningiomas and preserving the superior petrosal veins (SPVs) and the superior petrosal sinus (SPS).

METHODS

 A retrospective analysis of 26 patients harboring a true petroclival meningioma with a diameter ≥25 mm and undergoing surgery with the modified transpetrosal-transtentorial approach (MTTA) was performed.

RESULTS

 Fifty-four percent of 22 patients complained of severe headache at presentation. There was also complaint of cranial nerve (CN) deficit, with CN VII deficit being the most common (present in 42% of patients). The average tumor size (measured as maximum diameter) was 45.2 mm, and most of the tumors compressed the brainstem. Total resection was achieved in 12 patients (46.2%), whereas the others were excised subtotally (54.8%). Most of the patients had WHO grade I (96.1%) meningioma; only one had a grade II (3.8%) meningioma. In addition, clinical improvement and persistence of symptoms were observed in 17 (65.4%) and 8 (30.7%) patients, respectively, and postoperative permanent CN injury was observed in 3 (11.5%) patients.

CONCLUSION

 Using the MTTA, maximal resection with preservation of the CNs and neurovascular SPV-SPS complex can be achieved. Therefore, further studies and improvements of the technique are required to increase the total resection rate without neglecting the complications that may develop postoperatively.

Characteristics and management of the offending veins in microvascular decompression surgery for trigeminal neuralgia

The optimal technique of microvascular decompression (MVD) for trigeminal neuralgia (TN) caused by venous conflict remains unclear. The objectives of this study are to characterize the offending veins identified during MVD for TN and to evaluate intraoperative technique applied for their management. From 2007 till 2019, 308 MVD surgeries were performed in 288 consecutive patients with TN, and in 58 of them, pure venous conflict was identified. In 44 patients, the offending vein was interrupted, as was done for small veins arising from the cisternal trigeminal nerve (CN V) or its root entry zone (REZ) causing their stretching (19 cases), small veins on the surface of REZ (9 cases), transverse pontine vein (TPV) compressing REZ or distal CN V (12 cases), and superior petrosal vein (SPV) using flow conversion technique (4 cases). In 14 other cases, the offending vein was relocated, as was done for the SPV or the vein of cerebellopontine fissure (8 cases), TPV (3 cases), and the vein of middle cerebellar peduncle (3 cases). Complete pain relief after surgery was noted in 49 patients (84%). No one patient experienced major neurological deterioration. Postoperative facial numbness developed in 14 patients (24%), and in 8 of them, it was permanent. In 14 patients, MRI demonstrated venous infarction of the middle cerebellar peduncle, which was associated with the presence of any (P = 0.0180) and permanent (P = 0.0002) facial numbness. Ten patients experienced pain recurrence. Thus, 39 patients (67%) sustained complete pain relief at the last follow-up (median, 48 months), which was significantly associated with the presence of any (P = 0.0228) and permanent (P = 0.0427) postoperative facial numbness. In conclusion, in cases of TN, small offending veins arising from REZ and/or distal CN V and causing their stretching may be coagulated and cut. In many cases, TPV can be also interrupted safely or considered as collateral way for blood outflow. The main complication of such procedures is facial numbness, which is associated with the venous infarction of middle cerebellar peduncle and long-term complete pain relief.

Outcomes of microvascular decompression for trigeminal neuralgia with purely venous compression: A systematic review and meta-analysis

OBJECTIVE

Microvascular decompression (MVD) is a commonly-used treatment option for medically-refractory trigeminal neuralgia (TN) with arterial neurovascular compression. Pain control and recurrence rates after MVD in patients with purely venous compression are not well understood. In this systematic review and meta-analysis, we studied outcomes after MVD in patients with purely venous compression and reviewed the operative management in these patients.

METHODS

We performed a systematic review and meta-analysis following the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. We searched PubMed, Google Scholar, and Scopus databases for studies reporting surgical outcomes after MVD for purely venous compression. Pain control and recurrence rates were extracted and summarized. Studies that reported outcomes after mobilization/decompression compared with coagulation/transection of compressive veins were reviewed.

RESULTS

We identified and included 24 studies with a total of 330 patients in this study. 75.6 % of patients achieved a Barrow Neurological Institute (BNI) I pain score with a mean follow-up of 38.0 months. Pain recurred in 23.1 % of patients at a mean follow-up of 51.4 months. There was no significant difference in pain control outcomes between patients with mobilization/decompression and patients with coagulation/transection of compressive veins.

CONCLUSION

After MVD in patients with venous compression alone, pain control rates were similar to those reported for arterial compression, though recurrence rates were higher. There was no difference between vein coagulation/transection compared to mobilization/decompression. Further studies are needed to determine the optimal treatment paradigm for patients with purely venous compression.