How I do it: the biportal endoscopic inclined-ipsilateral technique to decompress the lumbar lateral recess

BACKGROUND

Various full-endoscopic techniques have been developed to reach the lateral recess of the lumbar spine. However, specialized surgical tools, including expensive spinal endoscopic systems, and a steeper learning curve to mastering the technique are required.

METHOD

We present a novel target-addressed unilateral biportal endoscopic technique to reach directly the lumbar lateral recess, particularly useful at L4-L5 and L5-S1. The technique follows an inclined-ipsilateral trajectory to preserve the lateral extension of ligamentum flavum and the facet joint as much as possible.

CONCLUSION

This technique was associated with all the advantages of minimally invasive decompressive procedures and outstanding outcomes.

Utility of flexible interventional endoscopy in endoscopic sinus surgery: a case series

PURPOSE

During endoscopic sinus surgery (ESS), difficult-to-reach pathologies need an extended endoscopic approach or an external approach. We started to use a flexible interventional endoscope (FIE) to evaluate the necessity of those approaches. The study's objective is to describe our experience and define patients who could benefit from this technique.

METHODS

We reviewed every patient who benefited from FIE associated with ESS at our tertiary University Hospital between January 2021 and February 2022.

RESULTS

During this period, we did 107 ESS, and 14 patients benefited from the FIE, representing 13% of our ESS. The median duration of the flexible endoscopy time was 14 min (4-38 min). We identified three groups of patients who can benefit from the FIE. The first one is for patients with a fungal infection, to control and to clean lateral recesses in a noninvasive manner. The second one is for patients with a pathology of the lateral frontal sinus, to remove the frontoethmoidal cells or mucocele with the biopsy forceps through the working channel. The third group is for patients with inverted papillomas, to precisely identify the insertion and to decide on the most appropriate surgical approach.

CONCLUSIONS

In selected cases, using flexible endoscopy during ESS helps decide the optimal surgical approach and sometimes treat the pathology through a limited approach. Prospective studies for each group of patients are needed to confirm the benefit of this new combined procedure.

Predictors for second-stage posterior direct decompression after lateral lumbar interbody fusion: a review of five hundred fifty-seven patients in the past five years

PURPOSE

To analyze the predictors for second-stage posterior direct decompression (PDD) after lateral lumbar interbody fusion (LLIF) procedure.

METHODS

We studied patients who underwent LLIF for degenerative lumbar spinal stenosis in the last five years, from July 2016 to June 2021. All surgical levels were grouped according to Schizas' central canal stenosis (CCS) classification, Pathria's facet joint degeneration (FJD) classification, Bartynski's lateral recess stenosis (LRS) classification, and Lee's foraminal stenosis (FS) classification. Second-stage PDD rates of each subgroup and their annual change were analyzed. Evaluation of risk factors associated with PDD was investigated.

RESULTS

A total of 901 segments from 557 patients were included. The overall PDD rate was 29.97%. An overall PDD rate of 75.21% for grade D CCS, 29.74% for grade C CCS, 41.67% for grade 3 FJD, 37.61% for grade 3 LRS, and 40.70% for grade 3 FS was shown. While there was a continuous decline in annual PDD rate in the past four years, the annual PDD rate for grade D remained at very high levels. Logistic regression analysis had shown grade D CCS as the utmost risk factor for PDD (OR = 17.77). And grade 3 LRS (OR = 4.63), grade 3 FS (OR = 2.42), grade C CCS (OR = 2.41), and grade 3 FJD (OR = 2.04) were also moderately correlated with PDD, which meant they only moderately increased the risk of PDD.

CONCLUSION

Extreme severe lumbar CCS (grade D) is the greatest determinant to perform the second-stage PDD procedure after LLIF.

Comparison Between a Single Subpedicular Transforaminal Epidural Steroid Injection and Lateral Recess Steroid Injection in Reducing Paracentral Disc Herniation-Related Chronic Neuropathic Leg Pain: A Retrospective Study

BACKGROUND

This retrospective study compares the results of 2 different techniques of transforaminal epidural steroid injection (TFESI)-subpedicular (SP-TFESI) and lateral recess epidural steroid injection (LRSI) in relieving chronic lumbar radicular pain.

METHODS

Records of 97 patients who had undergone injection for unilateral lumbar radicular pain and had a paracentral disc were analyzed. Numerical rating scale (NRS) and Oswestry Disability Index (ODI) scores were measured at baseline and at 2, 4, 12, and 24 weeks thereafter.

RESULTS

At 24 weeks, the NRS was significantly lower than the baseline in both groups; NRS in the LRSI group was significantly lower than NRS in the SP-TFESI group at 12 and 24 weeks (P = 0.02 each). ODI score was also significantly lower in the LRSI group through the 12-week time point (P = 0.003 at 2 weeks; P = 0.009 at 4 weeks; P = 0.02 at 12 weeks). At the end of 24 weeks, a significantly greater number of patients in the LRSI group achieved minimal clinically important difference for NRS and ODI (P = 0.008 and 0.016, respectively).

CONCLUSIONS

At the end of 24 weeks, LRSI appears to be a superior technique in relieving unilateral lumbar radicular pain due to a paracentral disc.

Minimally Invasive Lateral Paraorbital Approach for Repairing Lateral Recess of the Sphenoid Sinus Spinal Fluid Leak

BACKGROUND

Cerebrospinal fluid (CSF) leaks in the lateral recess of the sphenoid sinus (LRSS) are typically spontaneous in nature and require surgical repair. Endoscopic endonasal approaches have become the mainstay of CSF leak repair in the LRSS, though they remain technically challenging and place the vidian nerve (VN) and sphenopalatine artery (SPA) at risk. Here we present a lateral paraorbital approach (LPOA) as a minimally invasive transcranial VN and SPA sparing alternative for LRSS CSF leak repairs.

CASE DESCRIPTION

A 41-year-old African American woman presented with headaches and was found to have a spontaneous CSF leak in the LRSS. A LPOA was used to repair the CSF leak. An incision was made along the frontal process of zygoma (FPZ). Removal of the overhanging portion of the FPZ while sparing the lateral orbital rim and retraction of the temporalis muscle allowed for a tangential approach to the LRSS. A small encephalocele was seen and resected; the defect was identified and repaired with onlay DuraGen (Integra LifeSciences, Princeton, NJ) and Dura Repair (J&J Medical Devices, New Brunswick, NJ). There were no postoperative complications or recurrence of CSF leak.

CONCLUSIONS

The LPOA can be a useful alternative approach to the LRSS for CSF leak repair. The lateral-to-medial approach to defects in this area provides a shorter working distance while avoiding critical neurovascular structures.

Indications and Contraindications of Full-Endoscopic Interlaminar Lumbar Decompression

BACKGROUND

Spinal stenosis is a common disease with an increasing incidence. Narrowing of the spinal canal is caused by bone and soft tissue degeneration, such as osteophyte formation, facet and ligamentum flavum hypertrophy, and disc herniation. Various surgical techniques have been used to treat spinal canal stenosis, including open, tubular, microsurgical decompression, and fusion surgery. This article presents the technique for full-endoscopic interlaminar bilateral decompression of the lumbar spine.

METHODS

Surgical approach, anatomy, pathology, indications, contraindications, and surgical equipment are described.

RESULTS

With well-chosen endoscopic equipment, surgical time can be reduced with minimal collateral damage. Clear advantages of full-endoscopic decompression over open or other minimally invasive surgery methods are demonstrated in many clinical studies. The endoscopic technique has been shown to be effective in spinal canal decompression with good to excellent clinical results. The interlaminar endoscopic approach minimizes iatrogenic injury to the stabilizing anatomic structures while achieving full unilateral and bilateral decompression. A significant improvement in pain and functional outcome scores with low complication rates has been demonstrated.

CONCLUSIONS

This technique is safe for lumbar spinal decompression and more minimally invasive than a microendoscopic approach. However, this technique should be performed by surgeons with advanced skills. Endoscopy could become the gold standard for treatment of canal stenosis in the near future.

Anatomical Relationship of the Vertebral Artery With the Lateral Recess: Clinical Importance for Posterior Cervical Foraminotomy

Objective

Vertebral artery injuries during posterior cervical foraminotomy are rare, but can be fatal. Therefore, we investigated the anatomical correlation between the lateral recess and the vertebral artery.

Methods

On axial cuts of cervical magnetic resonance imaging from 108 patients, we measured the distance between the vertebral arteries and the medial border of the facet joints. The anatomical vertebro-facet distance (AVFD), surgical vertebro-facet distance (SVFD), and vertebro-facet angle (VFA) were measured.

Results

The mean AVFD values on the right side at the C3–4, C4–5, C5–6, and C6–7 levels showed statistically significant differences. On the right side, the mean SVFD values were equivalent to the AVFD values. The mean values of the VFA on the right side at all levels showed statistically significant differences. For all measurements, the greatest differences were seen between the C5–6 and C6–7 levels, and higher levels were associated with smaller distances from the lateral recess. The mean values of the AVFD on the right and left sides showed statistically significant differences at all levels, and the distances on the left were smaller than those on the right.

Conclusion

The vertebral artery is closer to the lateral recess at higher cervical levels than at lower cervical levels. The largest distances were found at the C5–6 and C6–7 levels, and the left vertebral arteries were closer to the lateral recess than the right vertebral arteries.

The Rhomboid Lip: Anatomy, Pathology, and Clinical Consideration in Neurosurgery

OBJECTIVE

To describe microsurgical anatomy of the rhomboid lip (RL) and to consider its role by presenting histology and clinical cases.

METHODS

We examined 10 (20 sides) formalin-fixed adult human cadaveric heads injected with colored silicone. A total of 20 RLs were examined posteriorly. We examined the expansion of the RL in the cerebellopontine cistern. We assessed the relationship between the RL and choroid plexus and the RL and cranial nerve IX and classified the RL. We also observed these relationships in clinical cases during surgeries and examined histologic assessments of the RL.

RESULTS

The RL was divided into 3 types, non-extension type, lateral extension type, and jugular foramen type, according to the relationship between the RL and choroid plexus. There were many variations of the extension of the RL. The jugular foramen type was rare.

CONCLUSIONS

Histologically, the RL is the remnant of the fourth ventricle covered with ependymal cells. Knowledge of the detailed anatomy and proper dissection of the RL may help surgeons to obtain good visualization of structures around the foramen of Luschka.

Paediatric auditory brainstem implantation: The South Asian experience

INTRODUCTION

Paediatric Auditory Brainstem Implantation (ABI) is indicated for children with congenital cochlear aplasia, absent/hypoplastic vestibulocochlear nerve, for whom cochlear implantation is not possible. Knowledge of the anatomical landmarks and variants in anatomy of the brainstem is vital for ABI surgery.

METHOD

Study was done at Auditory implant centre in Madras ENT research foundation, which includes 24 children who had undergone ABI surgery and are being followed up for 1 year, post operatively. Aims were to study the anatomical variants and the outcomes of ABI implantation. To determine if different anatomical variants effect placement of ABI electrode. To assess the patient outcomes by Categories of auditory Performance (CAP) scores and Speech Intelligibility Ratings (SIR) scores.

RESULTS

All the candidates showed gradual improvement in audiological and verbal outcomes after the ABI. The mean CAP and SIR scores after 6 months of AVHT were 2.07 and 1.37 respectively. After 1 year of auditory verbal rehabilitation therapy CAP was 3.42 and SIR was 2.33. Flocculus of the cerebellum can be of different grades. Though, there was difficulty in insertion of the electrode in subjects with anatomical variants, the outcomes were comparable with other subjects.

CONCLUSION

ABI surgery involves frequent anatomical variations surrounding the lateral recess which makes the positioning of the auditory prosthesis difficult. Variants during the surgery can make the placement of ABI electrodes difficult, but promising results were seen all the implantees.

Surgical anatomy of lateral recess in paediatric auditory brainstem implant patients and its clinical correlates including grades of flocculus

INTRODUCTION

Auditory brainstem implant (ABI), a standard technique in treatment of profound sensorineural hearing loss in patients with neurofibromatosis 2, is now being increasingly employed in children with congenital bilateral sensorineural hearing loss, as in Michele's deformity. A detailed knowledge of the relevant surgical anatomy of the lateral recess and its anatomical landmarks including the flocculus, the choroid plexus and the root entry zones of facial-vestibulocochlear and glossopharyngeal-vagus nerve complexes and their anatomical variants is mandatory, as it is the conduit for electrode array placement. The placement of electrode may be eased or impeded by these variations.

MATERIALS AND METHODS

Thirty-two children with congenital bilateral hearing loss underwent surgery through retromastoid suboccipital approach for placement of auditory brainstem implant. The preoperative anatomy was reviewed in detail during procedure and again later in the operative videos.

RESULTS

The flocculus was classified into four grades based on its anatomy and relations. Among these, grade II (11 children) was the commonest while grade IV (five children) was least common. Choroid plexus was variable in size across grades of flocculus. Difficulty in defining the anatomy was significantly more (p value = 0.003) in the group with higher grade flocculus (grade III and IV) than in lower grade flocculus (grade I and II).

CONCLUSION

The flocculus in these patients is classifiable into one of the four grades and the surgical nuances such as difficulty in defining the anatomy for placement of ABI are dependent on the characteristics exhibited by the floccular anatomy and relations.

Transforaminal Endoscopic Decompression for Lumbar Spinal Stenosis: A Novel Surgical Technique and Clinical Outcomes

OBJECTIVE

Transforaminal endoscopic treatment has been reported to be an effective treatment option in patients with lumbar disc herniation. However, it is rarely performed for spinal stenosis because of the limitation of endoscopic working mobility caused by the exiting nerve root and foraminous bony structure. The objective of this study was to describe a novel transforaminal endoscopic decompression technique for spinal stenosis and report the clinical results.

METHODS

From October 2015 to October 2016, 30 consecutive cases were diagnosed as lateral recess stenosis in our institution and underwent transforaminal endoscopic decompression. Visual analog scale (VAS) of back and leg pain and the Oswestry Disability Index (ODI) were measured preoperatively and at follow-up.

RESULTS

The mean ± SD value of preoperative VAS leg pain score was 7.6 ± 1.17. The score improved to 2.2 ± 1.11 at 1 week postoperatively, 1.73 ± 0.96 at 4 weeks postoperatively, and 1.63 ± 0.95 at 26 weeks postoperatively (P < 0.01). The mean ± SD value of the preoperative ODI score was 65.69 ± 14.22. The score improved to 24.29 ± 11.89 at 1 week postoperatively, 21.25 ± 9.25 at 4 weeks postoperatively, and 15.62 ± 10.49 at 26 weeks postoperatively (P < 0.01). There were no patients with postoperative infection, dural tear, delayed neurologic deterioration, or conversion to open surgery.

CONCLUSIONS

Transforaminal endoscopic decompression under local anesthesia could be an effective treatment method for the selected group of patients with spinal stenosis.

Schwannoma originating in lateral recess of the fourth ventricle

Intracranial schwannomas most commonly occur in relation to vestibular nerves followed by trigeminal nerves. Authors describe a very unusual case of schwannomas originating in lateral recess of the fourth ventricle. Tumor was completely excised micro-surgically via midline suboccipital craniectomy and C1 laminectomy. Dissection of the surgical specimen revealed that the tumor was completely free from surrounding structures and just hanging in the fourth ventricle. It was not attached to any cranial nerves, brain parenchyma, and blood vessel or to the dura mater. Histopathological examination confirmed the diagnosis of schwannoma. To our knowledge, no such case has been reported so far from this extremely rare location. Relevant literature is reviewed and hypothesis for ectopic location of these tumors has been highlighted.