How I do it? Uniportal full endoscopic contralateral approach for lumbar foraminal stenosis with double crush syndrome

Background

Evolution of endoscopic surgery provides equivalent results to open surgery with advantages of minimal invasive surgery. The literature on technique Uniportal Full endoscopic contralateral approach is scarce.

Methods

The endoscopic contralateral approach technique applies for patients presenting with double crush syndrome with foraminal and extraforminal stenosis. The key steps focus on contralateral ventral overriding superior articular process decompression, foraminal and extraforaminal discectomy, and lateral vertebral syndesmophyte decompression leading to enlargement of the contralateral foramen and extraforamen size.

Conclusion

The Uniportal Full endoscopic contralateral approach is a good alternative to open surgery or minimally invasive microscopic surgery through direct endoscopic visualization of the entire route of exiting nerve with no neural retraction allowing both lateral recess and foraminal and extraforaminal decompression all in one approach.

Electronic supplementary material

The online version of this article (10.1007/s00701-019-04157-z) contains supplementary material, which is available to authorized users.

Unilateral tubular approach for bilateral laminotomy: effect on ipsilateral and contralateral buttock and leg pain

PURPOSE

Tubular laminotomy is an effective procedure for treatment of lumbar spinal stenosis (LSS) and lateral recesses stenosis. Most surgeons familiar with the procedure agree that the tubular approach appears to afford a more complete decompression of the contralateral thecal sac and nerve root, as compared to the ipsilateral approach. With this study we sought to answer the question whether this is reflected in clinically significant differences between the ipsilateral and contralateral side pain improvements.

METHODS

In a retrospective case study, patients with LSS and lateral recesses stenosis who started out with VAS scores that were similar on the right and left side were included. All patients underwent a tubular (MIS) "over the top" laminotomy from a unilateral approach and through one incision. Surgeries were performed by a single surgeon in a single center. At the last follow-up, the extent of VAS score improvement on the approach (ipsilateral) side was compared to that of the contralateral side.

RESULTS

Thirty-three patients were included in. At the latest follow-up of 25.8 ± 3.4 months, there were statistically significant improvements in ODI and back VAS scores (p = 0.002 and p < 0.0001, respectively). In addition, buttock VAS scores were significantly improved both on the ipsilateral and the contralateral side (p < 0.001, and p = 0.001, respectively). Similarly, leg VAS scores were improved significantly on both sides (p < 0.001, and p = 0.001, respectively). There were no statistically significant differences between the extent of pain improvement on the ipsilateral and the contralateral side.

CONCLUSIONS

MIS tubular laminotomy through a unilateral approach results in clinically effective bilateral decompression of LSS and lateral recesses, regardless of the approach side.

Contralateral Keyhole Biportal Endoscopic Surgery for Ruptured Lumbar Herniated Disc: A Technical Feasibility and Early Clinical Outcomes

OBJECTIVE

Spinal endoscopic surgery is increasingly adapted as a minimal invasive technique, however, significant facet joint violation may be developed after ipsilateral laminectomy. The aim of this study is to introduce surgical technique of contralateral keyhole biportal endoscopic surgery (CKES) for ruptured lumbar disc and report it is early surgical outcomes with facet joint violation.

METHODS

Between January to December 2019, 27 patients with ruptured lumbar disc were underwent CKES. Simple radiographs were obtained to investigate development of iatrogenic instability or spondylolisthesis. Magnetic resonance imaging scan was checked about 8 hours after surgery to evaluate successful removal of ruptured disc and existence of facet joint violation. Clinical outcomes were assessed by modified MacNab criteria, visual analogue scale (VAS) scores of back and radicular pain.

RESULTS

The mean age of the patients was 62.8 ± 12.48 years. The average operative time and mean follow-up period were 57.1 ± 21.36 minutes and 8.1 ± 3.78 months, respectively. Compared to preoperative scores, the VAS scores of back and radicular pain were significantly improved. Modified MacNab outcome grade was good to excellent in 96.3% (26 out of 27 patients) of patients. The reduction rate of facet joint plane was about 4.9% after contralateral approach.

CONCLUSION

CKES may be considered as an excellent surgical option to treat ruptured lumbar disc without the development of iatrogenic instability. Low rate of facet joint reduction, good visualization of lateral recess, and identification of accurate midline of central spinal canal are advantages of the procedure.

Transient Cardiac Arrest Induced by Adenosine: A Tool for Contralateral Clipping of Internal Carotid Artery-Ophthalmic Segment Aneurysms

BACKGROUND

The disadvantages of a contralateral approach (CA) include deep and narrow surgical corridors and inconsistent ability to achieve proximal control of the supraclinoid internal carotid artery (ICA). However, a CA remains as a microsurgical option for selected ICA-ophthalmic (opht) segment aneurysms.

OBJECTIVE

To describe transient cardiac arrest induced by adenosine as an alternative tool to obtain proximal vascular control and soften the aneurysm sac in selected patients while performing a CA.

METHODS

From January 1998 to December 2013, we retrospectively identified 30 patients with ICA-opht segment aneurysms treated through a CA. Of those, 8 patients received an intravenous bolus of adenosine to induce transient cardiac arrest for softening of the aneurysm sac. We reviewed preoperative clinical status, characteristics of the contralateral aneurysm, adenosine doses, asystole time, recovery of normal circulation, outcome, and complications.

RESULTS

No preoperative cardiac or pulmonary pathologies were found in the study population. All contralateral ICA-opht segment aneurysms were unruptured, small, and saccular in shape. Transient cardiac arrest was induced because it was impossible to apply a temporary clip on the parent contralateral supraclinoid ICA. The median dose of adenosine was 22.5 mg (range, 5-50 mg) and the asystole time ranged from 20 to 40 seconds. All patients (n = 8) had good postoperative outcomes. No brain infarction or cardiac complications appeared postoperatively.

CONCLUSIONS

In selected patients, transient cardiac arrest induced by adenosine during a contralateral approach allows a brief flow arrest and softening of the aneurysm for safer exposure and clipping.

Contralateral Transcranial Approach to Tuberculum Sellae Meningiomas: Long-Term Visual Outcomes and Recurrence Rates

BACKGROUND

One of the most challenging aspects of the surgical treatment of tuberculum sellae meningioma is to control the involvement of the inferomedial side of the optic nerve, which is not directly visualized by an ipsilateral approach and thus requires optic nerve mobilization.

METHODS

Between 2003 and 2017, 21 consecutive patients were operated on using this approach. The surgical technique is described and the visual outcomes, resection and recurrence rates, and complications are analyzed.

RESULTS

Twenty patients were included, with a median follow-up of 5.6 years. Regarding visual outcomes, among the 19 patients who had a visual impairment before surgery, 14 (74%) improved, 2 were stabilized (10%), and 2 (10%) showed a worsening of the most-compromised optic nerve and 1 (5%) of the less-compromised optic nerve. Gross total resection was achieved in 18 patients (90%) and 1 patient experienced recurrence 10 years after the initial surgery.

CONCLUSIONS

This approach allowed lower mobilization of the compromised optic nerve, better preservation of the vascularization of the visual pathways, and direct access to the inferomedial side of the optic nerve.

Contralateral Approach for Minimally Invasive Treatment of Upper Lumbar Intervertebral Disc Herniation: Technical Note and Case Series

BACKGROUND

Upper lumbar disc herniations comprise only 1%-2% of all lumbar disc herniations. Patients exhibit nonspecific signs and symptoms in comparison to predictable radiculopathies, as seen in lower lumbar disc herniations. The unique anatomic characteristics of the upper lumbar spine present several challenges for safe and effective surgical treatment of disc herniations. The authors review the anatomy of the upper lumbar spine, describe a novel approach to upper lumbar disc herniations, and present 3 cases with a focus on clinical outcome and technical pearls.

METHODS

Conventional techniques for upper lumbar discectomy require a near complete facetectomy and pars interarticularis resection for adequate bony exposure, possibly leading to spinal destabilization. A tubular retractor system was used to approach upper lumbar disc herniation using a contralateral minimally invasive technique, while completely preserving the facet complex and pars interarticularis.

RESULTS

We report 3 cases of minimally invasive discectomy from a contralateral approach. The patients experienced complete resolution of presenting symptoms, and the facet complexes were preserved. All cases were free of complications.

CONCLUSION

A contralateral approach to perform a minimally invasive discectomy for paracentral and central upper LDH is a safe, efficient, and effective technique. The approach that we describe in this study preserves the facet complex and may prevent future spinal instability.

Biportal Endoscopic Spinal Surgery for Bilateral Lumbar Foraminal Decompression by Switching Surgeon's Position and Primary 2 Portals: A Report of 2 Cases With Technical Note

Total facetectomy with/without fusion and facet-preserving microforaminotomy have been performed as conventional surgical treatments for lumbar foraminal stenosis (LFS). Recently, endoscopic spinal surgery has been introduced as a minimally invasive therapeutic modality of LFS by several authors. We report two cases of bilateral LFS at lumbosacral junction level successfully treated with a novel biportal endoscopic spine surgery (BES) technique using primary 2 portals. Two patients presented with chronic onset of back pain and neurogenic claudication symptom. They were diagnosed with bilateral LFS at L5-S1 level from magnetic resonance imaging and computed tomography preoperatively. BES for bilateral foraminal decompression was performed via contralateral approach bilaterally without additional skin incision or surgical trajectory by switching surgeon's position and primary 2 portals. After the surgery, preoperative patients' back and leg pain resolved and unilateral leg weakness of the 2 patients gradually improved in a few months. Postoperative radiologic images revealed significantly enlarged bilateral foramens at L5-S1 level.

Multistage "Hybrid" (Open and Endovascular) Surgical Treatment of Vertebral Artery-Thrombosed Giant Aneurysm by Trapping and Thrombectomy

BACKGROUND

Surgical treatment of vertebral artery (VA)-thrombosed giant aneurysms requires achieving both obliteration of the parent artery to prevent bleeding and dome thrombectomy to relieve the brain stem from mass effect. To secure both proximal and distal control of complex VA aneurysms, the contralateral approach to the aneurysm might be a useful alternative, as previously described. We successfully treated a case of VA-thrombosed giant aneurysm in a new, original way by combining craniotomy (ipsilateral and contralateral) and the endovascular technique.

CASE DESCRIPTION

A 48-year-old man presented with a thrombosed giant aneurysm of the right VA compressing the brain stem. Treatment consisted of endovascular proximal ligation of the VA followed by 2-staged craniotomy for complete trapping of the aneurysm and intra-aneurysmal thrombectomy. The VA distal to the aneurysm was obliterated via contralateral craniotomy as only that provided adequate working space. Finally, intra-aneurysmal partial thrombectomy was performed through an ipsilateral craniotomy, which also made possible the obliteration of the eventually dangerous remaining vasa vasorum and additional proximal ligation of the VA.

CONCLUSIONS

Based on pathologic and surgical anatomical characteristics, a combination of an endovascular procedure with 2-staged craniotomy for complete trapping, thrombectomy, and vasa vasorum obliteration could be considered a feasible way to treat VA-thrombosed giant aneurysms located ventral to the brain stem and have their distal neck portions/patent vessel beyond the midline toward the contralateral side.

Preoperative portal vein embolization with a combination of trisacryl microspheres, gelfoam and coils

PURPOSE

To evaluate the safety and efficiency of preoperative portal vein embolization (PVE) with a combination of trisacryl microspheres, gelfoam and coils for inducing lobar hypertrophy in hepatobiliary malignancy patients.

MATERIALS AND METHODS

PVE was performed by a percutaneous left approach in 63 patients with hepatic malignancy (hepatocarcinoma=38, colorectal metastasis=14, cholangiocarcinoma=11). The indication of PVE and surgery was evaluated by hepatic tumor board take into consideration to the tumor extension and the hepatic volume on initial and post-embolization CT-scans. The total functional liver volume (TELV) and future liver remnant (FLR) volume were measured before and 24±5days after PVE to assess FLR, TELV and FLR/TELV ratios. Efficiency evaluation was based on FLR increase, the ability to perform the hepatectomy and the hepatic function after surgery. Safety evaluation was determined by clinical and biological follow-up after embolization and surgery.

RESULTS

PVE was successful in all the patients. The mean FLR volume increases by 57±56% after embolization (449±180cm(3) to 663±254cm(3)) (P<0.0001). The FLR/TELV ratio increases by 11% after PVE (25±8% to 36±12%). Three minors' complications were registered without impact on surgery, and four patients developed portal hypertension. Forty-nine patients underwent hepatectomy; none of them developed liver failure. Surgery was not performed in 14 patients due to tumor progression (n=9), inadequate hypertrophy of FLR (n=1) and portal hypertension (n=4).

CONCLUSION

Preoperative PVE with a combination of trisacryl microspheres, gelfoam and coils is a safe and effective method for inducing contralateral hypertrophy before right hepatectomy in patients with advanced hepatobiliary malignancy.

A literature review concerning contralateral approaches to paraclinoid internal carotid artery aneurysms

Ipsilateral approaches remain the standard technique for clipping paraclinoid aneurysms. Surgeons must however be prepared to deal with bony and neural structures restricting accessibility. The application of a contralateral approach has been proposed claiming that some structures in the region can be better exposed from this side. Yet, only few case series have been published evaluating this approach, and there is a lack of systematic reviews assessing its specific advantages and disadvantages. We performed a structured literature search and identified 19 relevant publications summarizing 138 paraclinoid aneurysms operated via a contralateral approach. Patient's age ranged from 19 to 79 years. Aneurysm size mainly varied between 2 and 10 mm and only three articles reported larger aneurysms. Most aneurysms were located at the origin of the ophthalmic artery, followed by the superior hypophyseal artery and carotid cave. All aneurysm protruded from the medial aspect of the carotid artery. Interestingly, minimal or even no optic nerve mobilization was required during exposure from the contralateral side. Strategies to achieve proximal control of the carotid artery were balloon occlusion and clinoid segment or cervical carotid exposure. Successful aneurysm occlusion was achieved in 135 cases, while 3 ophthalmic aneurysms had to be wrapped only. Complications including visual deterioration, CSF fistula, wound infection, vasospasm, artery dissection, infarction, and anosmia occurred in a low percentage of cases. We conclude that a contralateral approach can be effective and should be considered for clipping carefully selected cases of unruptured aneurysms arising from medial aspects of the above listed vessels.

A Contralateral Transcondylar Fossa Approach with Bilateral V3 Segment Exposure for Repairing Complex Vertebral Artery Aneurysms

BACKGROUND AND IMPORTANCE

Microsurgical treatment for vertebral artery aneurysms can be approached through the lateral aspect of the brainstem and cerebellum. A contralateral approach may be selected in complex aneurysms with tortuous running and the intracranial vertebral artery distal to the aneurysm located in the contralateral cerebellopontine angle. When repairing the aneurysm, exposing the V3 segment before craniotomy is advantageous. We describe the detailed surgical procedures of the contralateral transcondylar fossa approach with bilateral V3 segment exposure for the repair of a complex vertebral artery aneurysm.

CLINICAL PRESENTATION

A 48-year-old woman presented with a 23-mm unruptured thrombosed fusiform aneurysm in the right vertebral artery. The aneurysm and the V4 segment distal to it deviated to the left, and the aneurysm was compressing the left anterior aspect of the medulla oblongata. We treated the patient with trapping and thrombectomy, using a contralateral transcondylar fossa approach with bilateral V3 exposure. During the procedure, proximal vascular control was achieved by occluding the contralateral V3 segment and distal control was achieved by occluding the V4 segment. The aneurysm was successfully trapped and decompressed. The patient's postoperative course was good and she was discharged with a modified Rankin Scale score of 0.

CONCLUSIONS

The contralateral transcondylar fossa approach with bilateral V3 exposure is feasible for the repair of complex vertebral artery aneurysms showing a deviated and difficult to access V4 segment proximal to the aneurysm. Bilateral V3 exposure may also facilitate aneurysm bypass procedures such as those using a V3-V4 anastomosis.

Contralateral interlaminar approach for intraforaminal lumbar degenerative disease with special emphasis on L5-S1 level: A technical note

Background:

Intraforaminal disc herniations at the L5-S1 level are extremely surgically challenging lesions. Intracanal approaches frequently require partial or total facetectomy, which may lead to instability. Solely extraforaminal approaches may offer limited visualization of the more medial superiorly exiting and inferiorly exiting nerve roots; this approach is also more complicated at L5-S1 due to the often large L5 transverse process and the iliac wing.

Methods:

Nine patients with intraforaminal L5-S1 disc herniations, foraminal stenosis, or synovial cysts underwent contralateral interlaminar approaches for lesion resection. Preoperative and postoperative visual analog scale scores were evaluated, and complications were reviewed.

Results:

All 9 patients demonstrated immediate postoperative clinical improvement. None of the patients exhibited complications and none developed instability or neuropathic disorders.

Conclusions:

Although the number of cases in our sample was very small (9 in total), the contralateral interlaminar approach appeared to effectively address multiple degenerative L5-S1 foraminal pathologies. Large studies are needed to further evaluate the pros and cons of this approach.

New classification of facet joint synovial cysts

PURPOSE

Facet cysts develop due to degeneration of the zygapophyseal joints and can lead to radiculopathy and neurogenic claudication. Various surgical options are available for facet cyst excision. The aim was to facilitate surgical treatment of lumbar facet cysts based on a new classification.

METHODS

We retrospectively analyzed all patients of the last 10 years in whom a facet cyst was surgically removed (ipsilateral laminotomy, contralateral laminotomy, and segmental fusion). Several radiological parameters were analyzed and correlated with the patients' outcome (residual symptoms, perioperative complications, need for re-operation, need for secondary fusion, facet cyst recurrence).

RESULTS

One hundred eleven patients (55 women; median age 64 years) could be identified. Thirty-three (48%) of 69 cases, for which MRI data were available, were classified as medial facet cyst (compressing the spinal canal), 6 facet cysts were localized intraforaminal (9%) and 30 cases (43%) mediolateral (combination of both). The contralateral approach had the lowest rate for revision surgery (7.5%, p = .038) and the lowest prevalence of residual complaints (7.5%, p = .109). A spondylolisthesis and a higher/steeper angle of the facet joints were associated with poorer patient outcome.

CONCLUSIONS

Lateral facet joint cysts are best resected by a contralateral approach offering the best outcome while medial cysts are suitable for removal by an ipsilateral laminotomy. The approach of mediolateral cysts can be determined by the width of the lamina and the angle of the joint. Segmental fusion should be considered in cases with detected spondylolisthesis and/or steep facet joints.

The Dural Dark-Side Approach for falcine and tentorial meningioma: A surgical series of five patients

INTRODUCTION

Falcine or tentorial meningioma can be complex to resect. When large meningiomas are located in eloquent areas, a direct ipsilateral surgical approach may cause brain injury and postoperative neurological deficits. In this series, 5 patients were surgically treated using a contralateral transfalcine or transtentorial approach to minimize brain retraction. This strategy was called the Dural Dark-Side Approach (DDSA). The aim was to analyze the quality of tumor resection and postoperative outcome.

MATERIAL AND METHODS

In our department, from June 2018 to January 2020, 5 patients underwent microsurgical DDSA for resection of 4 falcine and 1 tentorial meningioma. All tumors were selected on the following two criteria: large>40mm diameter tumor, with surrounding functional cortex. Clinical and radiologic data were retrospectively analyzed.

RESULTS AND DISCUSSION

Mean follow-up was 20 months. No patients required use of a rigid retractor during surgery. Gross total resection was performed in 3 patients and near-total resection in 2. All patients had favorable neurologic outcome. Postoperative MRI showed no ipsilateral or contralateral brain lesions.

CONCLUSION

This series suggested that meticulous DDSA allows excellent resection in selected large falcine or tentorial meningioma. The approach offered a safe and effective surgical corridor without injuring the surrounding healthy parenchyma.

Steerable sheath for exclusively femoral bilateral extension of previous fenestrated endovascular aneurysm repair with iliac branch devices

We report the treatment of type Ib endoleak after fenestrated endovascular aneurysm repair (FEVAR) with iliac branch device (IBD) to allow exclusive transfemoral access without a femoral-to-femoral through-and-through wire. The patient was treated with fenestrated endovascular aneurysm repair and showed expansion of the aneurysm owing to a type Ib endoleak. An IBD was implanted by the use of a contralateral steerable sheath for internal iliac artery catheterizing. A computed tomography scan showed the patency of the target vessels and resolution of the endoleak. The use of a steerable sheath without femoral-to-femoral through-and-through wire to bridge the internal iliac artery in patients receiving an IBD after prior EVAR is feasible and avoids the risks associated with upper extremity access.

Comprehensive Anatomic Assessment of Ipsilateral Pterional Versus Contralateral Subfrontal Approaches to the Internal Carotid Ophthalmic Segment: A Cadaveric Study and Three-Dimensional Simulation

OBJECTIVE

Medially pointing aneurysms of the ophthalmic segment of the internal carotid artery (oICA) represent a neurosurgical challenge. Conventional ipsilateral approaches require internal carotid artery and optic nerve (ON) mobilization as well as anterior clinoidectomy (AC), all associated with increased surgical risk. Contralateral approaches could provide a better exposure of the superomedial aspect of the oICA, ophthalmic artery, and superior hypophyseal artery, sparing AC and internal carotid artery or ON mobilization. However, the microsurgical anatomy of this approach has not been systematically studied. In the present work, we exhaustibly analyzed the anatomic and morphometric characteristics of contralateral approaches to the oICA and compared them with those from ipsilateral approaches.

METHODS

We assessed 36 ipsilateral and contralateral approaches to the oICAs in cadaveric specimens and live patients, using for the latter a three-dimensional virtual reality (VR) system.

RESULTS

Contralateral approaches spared sylvian fissure dissection and required only minimal frontal lobe retraction. The ipsilateral and contralateral oICA were found at a depth of 49.2 ± 1.8 mm (VR, 50.1 ± 2.92 mm) and 65.1 ± 1.5 mm (VR, 66.05 ± 3.364 mm) respectively. The exposure of the superomedial aspect of oICA was 7.25 ± 0.86 mm (VR: 6 ± 1 mm) contralaterally without ON mobilization and 2.44 ± 0.51 mm (VR, 2 ± 1 mm) ipsilaterally even after AC. Statistical analysis showed that, for nonprefixed chiasm, contralateral approaches achieved a significantly higher exposure of the ophthalmic artery, superior hypophyseal artery, and the superomedial aspect of the oICA with its perforating branches (all P < 0.01).

CONCLUSIONS

Contralateral approaches may enable successful exposure of the oICA and related vascular structures, reducing the need for AC or ON mobilization. Systematic clinical/surgical studies are needed to further determine the effectiveness and safety of the approach.

The approach angle to the interoptic triangle limits surgical workspace when targeting the contralateral internal carotid artery

BACKGROUND

The interoptic triangle (IOT) offers a key access to the contralateral carotid artery's ophthalmic segment (oICA) and its perforating branches (PB), the ophthalmic artery (OA), and the superior hypophyseal artery (SHA). It has been previously reported that the assessment of IOT's size is relevant when attempting approaches to the contralateral oICA. However, previous studies have overseen that, since the oICA is a paramedian structure and a lateralized contralateral approach trajectory is then required, the real access to the oICA is further limited by the approach angle adopted by the surgeon with respect to the IOT's plane. For this reason, we determined the surgical accessibility to the contralateral oICA and its branches though the IOT by characterizing the morphometry of this triangle relative to the optimal contralateral approach angle.

METHODS

We defined the "relative interoptic triangle" (rIOT) as the two-dimensional projection of the IOT to the surgeon's view, when the microscope has been positioned with a certain angle with respect to the midline to allow the maximal contralateral oICA visualization. We correlated the surface of the rIOT to the visualization of oICA, OA, SHA, and PBs on 8 cadavers and 10 clinical datasets, using for the last a 3D-virtual reality system.

RESULTS

A larger rIOT correlated positively with the exposure of the contralateral oICA (R = 0.967, p < 0.001), OA (R = 0.92, p < 0.001), SHA (R = 0.917, p < 0.001), and the number of perforant vessels of the oICA visible (R = 0.862, p < 0.001). The exposed length of oICA, OA, SHA, and number PB observed increased as rIOT's surface enlarged. The correlation patterns observed by virtual 3D-planning matched the anatomical findings closely.

CONCLUSIONS

The exposure of contralateral oICA, OA, SHA, and PB directly correlates to rIOT's surface. Therefore, preoperative assessment of rIOT's surface is helpful when considering contralateral approaches to the oICA. A virtual 3D planning tool greatly facilitates this assessment.

Contralateral Transfalcine Approach to Deep Parasagittal Arteriovenous Malformations-Technical Note

BACKGROUND

Resection of deep medial frontal and parietal arteriovenous malformations (AVMs) is often challenging due to a tangential angle of attack and deep, narrow working corridor. Adequate visualization of the AVM and its feeding arteries without brain retraction is of particular importance when operating in or near eloquent cortical areas, where brain manipulation could inadvertently result in neurologic deficits. The aim of this paper is to provide a step-by-step description of surgical approach and report our experience with the contralateral transfalcine approach for resection of deep-seated parasagittal AVMs.

METHODS

Contralateral transfalcine resection of deep frontal, parietal, and cingulate gyrus AVMs was performed with the unaffected hemisphere positioned in a gravity-dependent manner in 5 cases. Surgical procedures were video documented, and an illustrative case is presented. All 5 patients had a modified Rankin Scale score of 0 or 1 at the last follow-up.

RESULTS

Complete resection of the AVM was achieved in all 5 cases. No permanent major neurologic deficit was observed postoperatively. This approach allowed a superior visualization of arterial feeders, the parenchymal side of the AVM, and an early control of small parenchymal feeders while minimizing retraction of the brain.

CONCLUSIONS

The contralateral transfalcine approach is a useful technique in the cerebrovascular surgeon's armamentarium for management of deep-seated medial frontal, parietal, and cingulate gyrus AVMs in or around eloquent brain areas, allowing to minimize normal brain retraction and avoid associated neurologic deficits.

Contralateral approach for the treatment of a distal supraclinoid aneurysm: a technical case report

Background: When treating intracranial aneurysms with open microsurgery, rare cases arise in which an ipsilateral approach leads to poor visualization, lack of proximal control, or potential damage to nearby vital structures due to the anatomy of the aneurysm. Case Description: We describe a patient with a small, unruptured aneurysm arising from the medial aspect of the distal supraclinoid internal carotid artery (ICA), just below the ICA bifurcation. A contralateral surgical approach was chosen because our view of the aneurysm from an ipsilateral approach would have been obstructed by the ICA. The contralateral approach provided excellent exposure of the aneurysm and allowed for precise clip placement without complications. Conclusions: Contralateral approaches may be a good option for some small medially pointing aneurysm of large proximal cerebral arteries.

Contralateral Clipping of Multiple Intracranial Aneurysms

The reported incidence of multiple intracranial aneurysms (MIA) is approximately 7-35% of all intracranial aneurysms. The primary goal in the management of MIAs is to secure the ruptured aneurysm and to treat as many of the remaining lesions as possible without affecting the outcome of the patient. In recent era endovascular treatment is the preferred treatment of multiple bilateral intracranial aneurysms if all aneurysms are amenable to addressed in single stage. But most often all aneurysms were not possible to addressed due to complexity of different aneurysms, technical limitation and infrastructure. In such scenarios options left were two stage sequential craniotomy on either sides and clipping of bilateral aneurysms or unilateral craniotomy and clipping of bilateral MIA. Bilateral two stage surgery or two stage endovascular treatment caries risk of bleeding from one of the untreated aneurysms, morbidity due to two stage and increase the cost of treatment. In properly selected cases of unilateral craniotomy and clipping of bilateral MIA secure the all aneurysm in one stage and decreased morbidity and cost of treatment. When patient selection done meticulously, clipping of MIA including contralateral side aneurysms is feasible and safe.

Endoscopic-assisted contralateral interhemispheric transfalcine keyhole approach for falcine meningioma: How I do it

BACKGROUND

Although the ipsilateral craniotomy approach has been used for the removal of falcine meningioma (FM), we report a case of FM that was minimally invasively removed using a contralateral interhemispheric approach assisted with endoscopy.

METHODS

We used a contralateral approach with a small craniotomy of the FM. The tumor was detached from the surrounding tissue during internal decompression. It was dissected and coagulated endoscopically in a blind spot under a microscope, and a Simpson Grade I resection was achieved.

CONCLUSION

A small craniotomy with a contralateral interhemispheric approach assisted by endoscopy allowed minimally invasive tumor removal without complications.

Right gyrus cinguli low-grade astrocytoma recurrence removed through a contralateral transfalcine approach with a 4K-3D exoscope

BACKGROUND

Brain tumor surgery has been using operative microscope for years. Recently, thanks to developments in surgical technology with procedures performed on head-up displays, exoscopes have been introduced as an alternative to microscopic vision.

CASE PRESENTATION

We present a case of a 46-year-old patient with a low-grade glioma recurrence of the right gyrus cinguli removed with a contralateral transfalcine approach using an exoscope (ORBEYE 4K-three-dimensional (3D) exoscope, Sony Olympus Medical Solutions Inc., Tokyo, Japan). The operating room setup for this approach is illustrated. During the procedure, the surgeon was seated with head and back in an upright position, while the camera was aligned with the surgical corridor. The exoscope provided detailed, high-quality 4K-3D images of the anatomical structures and optimal depth perception, making surgery accurate and precise. At the end of the resection, an intraoperative MRI scan showed complete removal of the lesion. The patient was discharged on postoperative day 4 with an excellent performance on neuropsychological examination.

CONCLUSIONS

In this clinical case the contralateral approach was favorable because the glioma was located close to the midline and because it offered a straight path to the tumor, minimizing retraction on the brain. The exoscope provided the surgeon with important advantages in terms of anatomical visualization and ergonomics during the entire procedure.

Unilateral Biportal Endoscopic Discectomy via the Contralateral Approach in Upward Migrated Foraminal Disc Herniations

OBJECTIVE

Lumbar upward migrated foraminal disc herniations are extremely rare and technically challenging to operate. In this study, a contralateral approach using unilateral biportal endoscopy, which has the advantages of structural protection, efficacy, and safety is presented.

METHODS

Between 2019 and December 2022, five patients with lumbar upward migrated foraminal disc herniations underwent unilateral biportal endoscopic discectomy via the contralateral approach. The patients were 4 males and 1 female patient. All patients had severe radicular pain. Neurological examination revealed sensory impairment and motor weakness in 2 patients but no deficits in the others. Magnetic resonance images confirmed lumbar upward migrated foraminal disc herniations in all patients.

RESULTS

The study shows a significant reduction in Oswestry Disability Index. Symptoms improved immediately after surgery in all patients, and satisfactory results were achieved at the last follow-up. No surgical complications or recurrent herniations were observed. The mean preoperative Oswestry Disability Index decreased from 44.6 to 11.4. In addition, mean preoperative Visual Analog Scale declined from 8.4 to 1.6. The patients were assessed after a follow-up period of at least 22 months, and their level of pain level was documented.

CONCLUSIONS

Although unilateral biportal endoscopic discectomy via the contralateral approach is not a common surgical procedure, it can offer a viable alternative for patients with lumbar upward migrated foraminal disc herniations.

Finite element mechanical analysis of ipsilateral approach and contralateral approach in unilateral bilateral endoscopic spine surgery

BACKGROUND

Unilateral bilateral endoscopic spine surgery (UBE) is often performed to treat lumbar spinal stenosis and disc herniation. It has become a prominent method in endoscopic spine surgery because of its very low learning curve and broader operative field of vision. Currently, the ipsilateral approach and contralateral approach have been established for disc herniation in the foraminal area, intervertebral foramen region, or pedicle region. The contralateral method offers many benefits over the ipsilateral approach, including less bone labour during microsurgical decompression and the preservation of facet joints. However, because it uses the interlaminar window approach, it inevitably involves osteotomy of the patient's superior and inferior articular processes, which may result in corresponding deterioration in the spine's biomechanical stability and subsequent adjacent facet joint diseases caused by facet joint degeneration postoperatively.

OBJECTIVE

As a result, the purpose of this work is to use a finite element model to evaluate how the ipsilateral approach and contralateral approach in unilateral bilateral endoscopic spine surgery affect spinal stability while treating identical intervertebral disc herniation.

STUDY DESIGN

In this study, a three-dimensional lumbar-sacral spine model was built and verified. Osteotomies were conducted for armpit-type lumbar disc herniation (LDH), periradicular-type LDH, and shoulder-type LDH. Postoperative lumbar spine models of the ipsilateral approach and contralateral approach in unilateral bilateral endoscopic spine surgery were developed. The von Mises stress on the endplate, shear force on the annulus fibrosus, pressure inside the intervertebral disc, and range of motion (ROM) of the L3 segment were all determined. The results of our well-validated model showed that osteotomy done in the ipsilateral approach deteriorated most biomechanical metrics.

RESULTS

In the majority of loading conditions, the contralateral approach caused the intervertebral disc's biomechanical properties to increase, and the ipsilateral approach caused the intervertebral disc's biomechanical properties to increase sharply more than the contralateral approach.

CONCLUSION

The contralateral approach, which is now extensively employed in unilateral bilateral endoscopic spine surgery, may be regarded as an ideal surgical alternative for treating lumbar disc herniation without producing iatrogenic instability. This approach has a low facet joint reduction rate, minimum soft tissue injury, and precisely identifies the midline of the central spinal canal during the retraction of the thecal sac and nerve roots.

Comparison of complications of biportal endoscopic discectomy: ipsilateral versus contralateral approach

BACKGROUND

Biportal endoscopic discectomy using the contralateral approach is effective for highly down- or upward-migrated disc removal and upper lumbar disc herniation. Despite its benefits, there are potential complications that have yet to be fully explored, including possible transient neurological deficits, excessive nerve pull, and incomplete discectomy. Thus, in this study, we aimed to understand these complications by comparing the contralateral and ipsilateral approaches for biportal endoscopic discectomy.

METHODS

This study included 326 patients who underwent biportal endoscopic discectomy, with 168 and 158 patients undergoing endoscopic discectomy via the contralateral and ipsilateral approaches, respectively, between March 2020 and July 2023. Patient demographic characteristics, operation level, length of hospital stay, blood loss, and operation time were reviewed. Complications included early recurrence, neurological deficits, postoperative pain, and long-term recurrence. Only single-level patients were included. Patients with infections, stenosis, instability, tumors, revision surgery, multilevel pathology, or ambiguous symptoms were excluded.

RESULTS

Operation time, length of hospital stay, and blood loss were similar between groups. L3-4 and L4-5 were the most common contralateral and ipsilateral approach discectomies, respectively. The frequency of dural tear occurrence showed no difference between groups. Early recurrence occurred more in the ipsilateral than in the contralateral approach group. Neurological deficits occurred more in the contralateral than in the ipsilateral approach group. Postoperative pain and long-term recurrence rates were not significantly different between groups. However, the rate of revision surgery due to long-term recurrence was higher in the contralateral than in the ipsilateral approach group.

CONCLUSIONS

No significant differences were observed in duration, postoperative pain, or long-term recurrence between the ipsilateral and contralateral approaches. However, early recurrence, neurological deficit, and revision surgery rates differed between the ipsilateral and contralateral approaches. The appropriate approach should be carefully determined according to the case before surgery. Contralateral discectomy may be an excellent surgical option.