Case Report: Direct Visualization of the Nervus Intermedius During the Microvascular Decompression Procedure: Should We Take It Seriously?

Background: Nervus intermedius neuralgia (NIN), known as geniculate neuralgia (GN), is an uncommon cranial nerve disease caused by an offending vessel compressing the nervus intermedius (NI). Microvascular decompression (MVD) has now become a valued treatment approach for NIN because it can resolve neurovascular conflict (NVC) at the root entry zone of the NI. In the era of continuously optimizing and improving the surgical technique of MVD, further minimization of all possible postoperative complications is not only welcome but also necessary.

Objective: The aim of this work is to assess the postoperative outcome of direct visualization of the NI during the MVD procedure.

Methods: This study retrospectively reviewed the clinical records of a group of seven consecutive patients with NIN who underwent MVD in the period of 2013–2020 in our clinic and 16 studies reported NIN patients who underwent MVD in the period of 2007–2020.

Results: In total, 91.3% of all patients experienced immediate and complete relief of cranial neuralgia after MVD. Six of 23 patients have experienced direct visualization of the NI intraoperatively, and 66.7% of those patients had complications such as facial paralysis, dysacousia, or a combination of these conditions postoperatively. Slight surgical approach-related complications such as complaints associated with excessive drainage of cerebrospinal fluid (CSF), nausea and vertigo, and delayed wound union were observed in 80% of the remaining 15 patients, and these symptoms are totally relieved in the telephone and outpatient follow-up after 6 months.

Conclusion: Our case series shows that MVD produced immediate pain relief in the majority of NIN patients. MVD carries surgical risk, especially in patients who experience direct visualization of the NI after mechanical stretch and blunt dissection in surgical procedures. Attempts to avoid mechanical stretch and blunt dissection of the compressed nerve were important for intraoperative neuroprotection, especially facial nerve protection

Are degenerative spondylolisthesis and further slippage postoperatively really issues in spinal stenosis surgery?

Background and aims Opinions diverge concerning the prognostic importance of preoperative degenerative spondylolisthesis in patients with lumbar spinal stenosis, as well as the significance of further slippage post-operatively following decompression alone. However, a slip is only one among several factors related to the topic, e.g. duration and intensity of back and leg pain, pre-operative walking ability, number of levels operated and not least the experience of the surgeon. Our aim was to take all of the above-mentioned factors into consideration when analysing the patients' clinical outcome, reported as Change in back pain, Change in leg pain, Overall satisfaction and Change in walking ability, with special emphasis on the possible importance of pre- and/or post-operative degenerative spondylolisthesis. Methods We studied 200 consecutive patients, mean follow-up time 81 months (range 62-108). Before treatment and on the follow-up occasion all patients answered the SF-36 questionnaire and assessed their back and leg pain on a visual analogue scale (VAS). At follow-up the patients were asked about possible changes in back and leg pain (completely free, much better, somewhat better, unchanged, somewhat worse, much worse) and whether they were; satisfied with the outcome, in doubt or not satisfied. Before treatment and at follow-up the presence or not of degenerative spondylolisthesis was determined in the lateral view on a plain X-ray or MRI. By use of a microsurgical technique decompression was achieved in all patients by bilateral laminotomy not sparing the midline ligaments, irrespective of a degenerative spondylolisthesis or not. Eight surgeons with different surgical experience performed the operations. Four separate multivariate analyses were conducted, one for each clinical outcome. The Lasso method was used for variable selection and multiple imputation was applied to handle missing values. Results At follow-up 78.5% of the patients were completely satisfied with the outcome. Minimal clinical important difference (MCID) was achieved for 69% of the patients. Before surgery 28 patients were able to walk more than 1 km compared to 111 at follow-up. The reoperation rate at 6.8 years was 12% further decompressions and 2.5% fusions at the index level. Post-operative slippage was equally common in patients with and without a preoperative slip (around 30%). There were no notable differences in outcome in patients with and without a preoperative slip and no effect of further slippage at the index or another level post-operatively. Nor could the statistical analysis show any of the other covariates (age, gender, duration and intensity of back and leg pain, pre-operative walking ability or number of levels operated) to be of statistically significant importance for predicting the outcome. In the univariate statistical analysis differences were found between the patients of individual surgeons regarding satisfaction, pain improvement, and reoperation rates in favour of surgical experience, which were, however, not statistically significant in the multivariate analysis. Conclusions None of the covariates, including pre-operative spondylolisthesis and further slippage post-operatively, were statistically significant for predicting the clinical outcome. Implication Our results provide no evidence for adding fusion to the decompression.

Intraspinal Lumbar Juxtaarticular Cyst Treatment Through CT-Guided Percutaneus Induced Rupture Results in a Favorable Patient Outcome

Juxta-articular cysts are synovial cysts originating from the facet joints or the flava ligaments. If they grow intra-spinally they can compress nervous structures and cause a variety of symptoms. Micro-neurosurgery is usually the treatment of choice. Alternatively to surgical treatment the cyst can be approached and treated with a CT guided percutaneous injection inducing rupture. After fulfilling strict selection criteria twenty patients (25% of all treated lumbar synovial cyst patients), were treated minimally invasive by this method from 2010-2016. The facet joint was punctured under CT guidance and a mixture of a local anesthetic and contrast liquid was injected until the cyst was blasted. The mean follow-up period was 1.1 years (range 2 weeks - 5 years).

Fifteen of twenty procedures were successful and cyst rupture was confirmed by CT-scans. Twelve of these fifteen patients experienced a significant improvement of their symptoms and needed no further intervention or surgical procedure up until now, three patients showed no clinical improvement and were treated surgically within one week after cyst rupture. In five patients it was technically not possible to rupture the cyst. These patients were treated microsurgically by cyst resection and dynamic stabilization or fusion procedures. The percutaneus rupture of juxtaarticular cysts has fewer risks and is cost effective compared to microsurgical resection. It may be an alternative to surgical treatment for a selected group of patients. However there are some limitations to the procedure though, such as difficult patient selection, unpredictable outcome or technical problems due to highly degenerated facet joints.

Microsurgical decompression of tumor of a rare posterior third ventricular pathology

Of the posterior third ventricular tumors, a papillary tumor of the pineal gland is a rare entity that originates from specialized ependymoma of the subcommissural organ. In this video narration, we present a case of a 33-year-old male with headaches and recent cognitive decline due to a posterior third ventricular lesion. The patient underwent a posterior interhemispheric approach, and a gross-total decompression was achieved with no signs of recurrence in a 2-year follow-up period. With this case we highlight the microsurgical technique employed for decompressing tumors of the posterior third ventricular region with preservation of eloquent structures and draining veins. The video can be found here: https://youtu.be/o0WbyOqmtX0 .