Step-wise pterional combined epidural and subdural approach to clip large carotid-ophthalmic segment aneurysms

Acta Neurochirurgica (2019) 161:607–610

Microsurgical clipping of large ophthalmic-carotid artery (OA) aneurysms is technically challenging. Among the reported approaches, pterional combined epidural and subdural approach is one of the efficient choices.

Method We have applied this approach to treat a 33-year old female patient with a left large OA aneurysm. The step-wise technical details of this approach are reported.

Conclusion We show that it is a safe way to clip large OA aneurysms through a step-wise pterional combined epidural and subdural approach, which could make a clear anatomy and a confident manipulation.

 

The transcortical equatorial approach for gliomas of the mesial temporal lobe

J Neurosurg 130:822–830, 2019

Many surgical approaches have been described for lesions within the mesial temporal lobe (MTL), but there are limited reports on the transcortical approach for the resection of tumors within this region. Here, the authors describe the technical considerations and functional outcomes in patients undergoing transcortical resection of gliomas of the MTL.

METHODS Patients with a glioma (WHO grades I–IV) located within the MTL who had undergone the transcortical approach in the period between 1998 and 2016 were identified through the University of California, San Francisco (UCSF) tumor registry and were classified according to tumor location: preuncus, uncus, hippocampus/parahippocampus, and various combinations of the former groups. Patient and tumor characteristics and outcomes were determined from operative, radiology, pathology, and other clinical reports that were available through the UCSF electronic medical record.

RESULTS Fifty patients with low- or high-grade glioma were identified. The mean patient age was 46.8 years, and the mean follow-up was 3 years. Seizures were the presenting symptom in 82% of cases. Schramm types A, C, and D represented 34%, 28%, and 38% of the tumors, and the majority of lesions were located at least in part within the hippocampus/ parahippocampus. For preuncus and preuncus/uncus tumors, a transcortical approach through the temporal pole allowed for resection. For most tumors of the uncus and those extending into the hippocampus/parahippocampus, a corticectomy was performed within the middle and/or inferior temporal gyri to approach the lesion. To locate the safest corridor for the corticectomy, language mapping was performed in 96.9% of the left-sided tumor cases, and subcortical motor mapping was performed in 52% of all cases. The mean volumetric extent of resection of low- and high-grade tumors was 89.5% and 96.0%, respectively, and did not differ by tumor location or Schramm type. By 3 months’ followup, 12 patients (24%) had residual deficits, most of which were visual field deficits. Three patients with left-sided tumors (9.4% of dominant-cortex lesions) experienced word-finding difficulty at 3 months after resection, but 2 of these patients demonstrated complete resolution of symptoms by 1 year.

CONCLUSIONS Mesial temporal lobe gliomas, including larger Schramm type C and D tumors, can be safely and aggressively resected via a transcortical equatorial approach when used in conjunction with cortical and subcortical mapping.

 

 

Anterior Reduction and Fusion of Cervical Facet Dislocations

Neurosurgery 84:388–395, 2019

Cervical facet dislocations are among the most common traumatic spinal injuries. Posterior, anterior, and combined surgical approaches have been described and are widely debated.

OBJECTIVE: To demonstrate efficacy in anterior-only surgical management for subaxial cervical facet dislocations.

METHODS: A consistent surgical algorithm for cervical facet dislocation was applied over a 19-yr period and analyzed retrospectively in adults with acute unilateral or bilateral facet dislocation of the subaxial cervical spine. The primary endpoint was maintenance of early cervical alignment. The need for additional posterior instrumented fusion was determined.

RESULTS: A database search identified 96 patients (mean age = 37.9, range = 14-74 yr, 68 (70%) male. The most common affected levels were C4-C5 (30), C5-C6 (29), and C6-C7 (30). Bilateral dislocation occurred in 51 patients (53%). Seventy-eight (81%) patients had neurological deficits, 31 (32%) being complete (Abbreviated Injury Score A) spinal cord injuries. Preoperative closed reductionwas attempted in 60 (63%) patients, with 33 (55%) achieving satisfactory alignment. After anterior cervical discectomy, reduction, allograft placement, and instrumentation, a total of 92 (96%) patients had achieved satisfactory realignment. Median time to surgery was 13.27 h. Eight (8%) patients required posterior fixation due to intraoperative determination of incomplete realignment (4; 4%) and development of early progressive deformity (4; 4%). Mean follow-up was 4.5 mo (range 0.5-24 mo) with 33 (34%) patients lost to follow-up.

CONCLUSION: Anterior approaches are viable for reduction and stabilization of cervical facet dislocations. Further prospective studies are required to evaluate clinical and longterm success.

Robot-assisted intravertebral augmentation corrects local kyphosis more effectively than a conventional fluoroscopy-guided technique

J Neurosurg Spine 30:289–295, 2019

Intravertebral augmentation (IVA) is a reliable minimally invasive technique for treating Magerl type A vertebral body fractures. However, poor correction of kyphotic angulation, the risk of cement leakage, and significant exposure to radiation (for the surgeon, the operating room staff, and the patient) remain significant issues. The authors conducted a study to assess the value of robot-assisted IVA (RA-IVA) for thoracolumbar vertebral body fractures.

METHODS The authors performed a retrospective, single-center study of patients who had undergone RA-IVA or conventional fluoroscopy-guided IVA (F-IVA) for thoracolumbar vertebral body fractures. Installation and operating times, guidance accuracy, residual local kyphosis, degree of restoration of vertebral body height, incidence of cement leakage, rate of morbidity, length of hospital stay, and radiation-related data were recorded.

RESULTS Data obtained in 30 patients who underwent RA-IVA were compared with those obtained in 30 patients who underwent F-IVA during the same period (the surgical indications were identical, but the surgeons were different). The mean ± SD installation time in the RA-IVA group (24 ± 7.5 minutes) was significantly shorter (p = 0.005) than that in the F-IVA group (26 ± 8 minutes). The mean operating time for the RA-IVA group (52 ± 11 minutes) was significantly longer (p = 0.026) than that for the F-IVA group (30 ± 11 minutes). All RA-IVAs and F-IVAs were Ravi’s scale grade A (no pedicle breach). The mean degree of residual local kyphosis (4.7° ± 3.15°) and the percentage of vertebral body height restoration (63.6% ± 21.4%) were significantly better after RA-IVA than after F-IVA (8.4° ± 5.4° and 30% ± 34%, respectively). The incidence of cement leakage was significantly lower in the RA-IVA group (p < 0.05). The mean length of hospital stay after surgery was 3.2 days for both groups. No surgery-related complications occurred in either group. With RA-IVA, the mean radiation exposure was 438 ± 147 mGy × cm for the patient and 30 ± 17 mGy for the surgeon.

CONCLUSIONS RA-IVA provided better vertebral body fracture correction than the conventional F-IVA. However, RAIVA requires more time than F-IVA.

 

The modified retrosigmoid approach

Acta Neurochirurgica (2019) 161:417–423

The traditional retrosigmoid (RS) approach provides limited exposure of the inferior compartment of the CPA, while radical skull base approaches are demanding and associated with significant morbidity.

Methods This study outlines the relevant surgical anatomy and the different surgical steps of a modified retrosigmoid (MRS) approach. Results The MRS provides enhanced exposure of the CPA and deep vascular structures resulting from a modified RS craniotomy and limited exposure of the sigmoid sinus.

Conclusion In selected posterior fossa lesions, this cisternal approach is a straightforward corridor that can be routinely performed as a safe alternative to radical cranial base approaches.

Modified unilateral approach for mid-third giant bifalcine meningiomas: resection using an oblique surgical trajectory and falx window

Acta Neurochirurgica (2019) 161:327–332

Utilizing the shortest available trajectory is the norm for excision of meningiomas. However, such an approach for the mid-third/central falcine meningiomas risks the adjoining draining veins and eloquent cortex. A larger size and bilaterality of such tumors adds to the surgical challenge. Herein, we report the surgical nuances of a modified unilateral approach in patients operated for giant bilateral symmetrical mid-third falcine meningiomas.

Methods Five such patients were operated. The clinico-radiologic data was studied at presentation and at the follow-up. The meningiomas were subclassified into those that were located in the anterior and posterior half of the central falx, and their surgical trajectory was chosen accordingly. The tumor was excised through an oblique anterior or a posterior trajectory instead of directly working over the major draining veins and eloquent brain. The falx was incised to create a surgical window and access the tumor on the contralateral side.

Results Four patients had meningiomas in the anterior half and one in the posterior half of central falx. Simpson excision was grade II in four patients. One patient showed small residual tumor and underwent stereotactic radiosurgery. The overall mean follow-up of the patients was 9.2 months. All the patients had good clinical outcome.

Conclusions Giant bifalcine meningiomas can be safely resected through a unilateral approach. Falx opening serves as a window to remove the tumor from the contralateral side. An oblique trajectory rather than an end-on access to these tumors minimizes the risk of venous and cortical injury.

Pterional versus superciliary keyhole approach

J Neurosurg 130:220–226, 2019

The objective of this study was to evaluate and compare the level of patient satisfaction and approachrelated patient complaints between a superciliary keyhole approach and a pterional approach.

METHODS Patients who underwent an ipsilateral superciliary keyhole approach and a contralateral pterional approach for bilateral intracranial aneurysms during an 11-year period were contacted and asked to complete a patient satisfaction questionnaire. The questionnaire covered 5 complaint areas related to the surgical approaches: craniotomy-related pain, sensory symptoms in the head, cosmetic complaints, palpable cranial irregularities, and limited mouth opening. The patients were asked to rate the 5 complaint areas on a scale from 0 (asymptomatic or very pleasant) to 4 (severely symptomatic or very unpleasant). Finally, the patients were asked to rate the level of overall satisfaction related to each surgical procedure on a visual analog scale (VAS) from 0 (most unsatisfactory) to 100 (most satisfactory).

RESULTS A total of 21 patients completed the patient satisfaction questionnaire during a follow-up clinic visit. For the superciliary procedures, no craniotomy-related pain, palpable irregularities, or limited mouth opening was reported, and only minor sensory symptoms (numbness in the forehead) and cosmetic complaints (short linear operative scar) were reported (score = 1) by 1 (4.8%) and 3 patients (14.3%), respectively. Compared with the pterional approach, the superciliary approach showed better outcomes regarding the incidence of craniotomy-related pain, cosmetic complaints, and palpable irregularities, with a significant between-approach difference (p < 0.05). Furthermore, the VAS score for patient satisfaction was significantly higher for the superciliary approach (mean 95.2 ± 6.0 [SD], range 80–100) than for the pterional approach (mean 71.4 ± 10.6, range 50–90). Moreover, for the pterional approach, a multiple linear regression analysis indicated that the crucial factors decreasing the level of patient satisfaction were cosmetic complaints, craniotomy- related pain, and sensory symptoms, in order of importance (p < 0.05).

CONCLUSIONS In successful cases in which the primary surgical goal of complete aneurysm clipping without postoperative complications is achieved, a superciliary keyhole approach provides a much higher level of patient satisfaction than a pterional approach, despite a facial wound. For a pterional approach, the patient satisfaction level is affected by the cosmetic results, craniotomy-related pain, and numbness behind the hairline, in order of importance.

 

Anterior clinoidectomy using an extradural and intradural 2-step hybrid technique

J Neurosurg 130:238–247, 2019

Anterior clinoidectomy is a difficult yet essential technique in skull base surgery. Two main techniques (extradural and intradural) with multiple modifications have been proposed to increase efficiency and avoid complications.

In this study, the authors sought to develop a hybrid technique based on localization of the optic strut (OS) to combine the advantages and avoid the disadvantages of both techniques. Ten cadaveric specimens were prepared for surgical simulation. After a standard pterional craniotomy, the anterior clinoid process (ACP) was resected in 2 steps. The segment anterior to the OS was resected extradurally, while the segment posterior to the OS was resected intradurally. The proposed technique was performed in 6 clinical cases to evaluate its safety and efficiency.

Anterior clinoidectomy was successfully performed in all cadaveric specimens and all 6 patients by using the proposed technique. The extradural phase enabled early decompression of the optic nerve while avoiding the adjacent internal carotid artery. The OS was drilled intradurally under direct visualization of the adjacent neurovascular structures. The described landmarks were easily identifiable and applicable in the surgically treated patients. No operative complication was encountered.

A proposed 2-step hybrid technique combines the advantages of the extradural and intradural techniques while avoiding their disadvantages. This technique allows reduced intradural drilling and subarachnoid bone dust deposition. Moreover, the most critical part of the clinoidectomy—that is, drilling of the OS and removal of the body of the ACP—is left for the intradural phase, when critical neurovascular structures can be directly viewed.

 

Lateral Lumbar Interbody Fusion Revisited: Complication Avoidance and Outcomes with the Mini-Open Approach

World Neurosurg. (2019) 121:e647-e653

OBJECTIVE: To discuss lessons learned from an initial lateral lumbar interbody fusion (LLIF) experience with a focus on evolving surgical technique, complication avoidance, and new motor and sensory outcomes after implementation of a modified surgical approach.

METHODS: A retrospective analysis of a prospectively collected series of all patients undergoing LLIF by the senior author (A.D.L.) from January 2010 to January 2018 after implementation of a modified surgical mini-open technique, compared with previously reported institutional results with the originally recommended percutaneous technique. LLIF-specific complications examined included groin/thigh sensory dysfunction, flank bulge/pseudohernia, psoas-pattern weakness, and femoral nerve injury.

RESULTS: The incidence (19%, n [ 98 patients) of groin/ thigh sensory dysfunction in our cohort was significantly lower than that of the historical control (60%, n [ 59) (P < 0.0001). The incidence of abdominal flank bulge/pseudohernia (2.0%, n[98 patients) in our cohort was improved but not significantly lower than that of the historical control (4.2%, n[118) (P[0.36). The incidence of psoas-patternweakness (3.1%, n[98) in our cohort was significantly lower than that of the historical control (23.7%, n [ 59) (P [ 0.0001). The incidence of femoral nerve injury (0%, n[98 patients) in our cohort was improved but was not significantly lower than that of the historical control (1.7%, n [118) (P[0.20).

CONCLUSIONS: The adoption of an exclusive mini-open muscle-splitting approach with first-look inspection of the lumbosacral plexus nerve elements may improve motor and sensory outcomes in general and the incidence of postoperative groin/thigh sensory dysfunction and psoaspattern weakness in particular.

Pterional, Pretemporal, and Orbitozygomatic Approaches: Anatomic and Comparative Study

World Neurosurg. (2019) 121:e398-e403

Although pterional craniotomy and its variants are the most used approaches in neurosurgery, few studies have evaluated their precise indications. We evaluate the pterional (PT), pretemporal (PreT), and orbitozygomatic (OZ) approaches through quantitative measurements of area, linear, and angular exposures of the major intracranial vascular structures.

METHODS: Eight fresh, adult cadavers were operated with the PT, followed by the PreT, and ending with the OZ approach. The working area, angular exposure of vascular structures and linear exposure of the basilar artery were measured. –

RESULTS: The OZ approach presented a wider area (1301.3215.9mm2)with an increase of 456.7mm2 compared with the PT and of 167.4 mm2 to the PreT (P [ 0.011). The extension from PT to PreT and OZ increases linear exposure of the basilar artery. When comparing the PreT and OZ, we found an increase in the horizontal and vertical angle to the bifurcation of the ipsilateral middle cerebral artery (P [0.005 and P [ 0.032, respectively), horizontal angle to the basilar artery tip (P [ 0.02), and horizontal angle to the contralateral ICA bifurcation (P [ 0.048). –

CONCLUSIONS: The OZ approach offered notable surgical advantages compared with the traditional PT and PreT regarding to the area of exposure and linear exposure to basilar artery. Regarding angle of attack, the orbital rim and zygomatic arch removal provided quantitatively wider exposure and increased surgical freedom. A detailed anatomic study for each patient and surgeon experience must be considered for individualized surgical approach indication.

Insular glioma surgery: an evolution of thought and practice


J Neurosurg 130:9–16, 2019

The goal of this article is to review the history of surgery for low- and high-grade gliomas located within the insula with particular focus on microsurgical technique, anatomical considerations, survival, and postoperative morbidity.

METHODS The authors reviewed the literature for published reports focused on insular region anatomy, neurophysiol- ogy, surgical approaches, and outcomes for adults with World Health Organization grade II–IV gliomas.

RESULTS While originally considered to pose too great a risk, insular glioma surgery can be performed safely due to the collective efforts of many individuals. Similar to resection of gliomas located within other cortical regions, maximal resection of gliomas within the insula offers patients greater survival time and superior seizure control for both newly diagnosed and recurrent tumors in this region. The identification and the preservation of M2 perforating and lateral len- ticulostriate arteries are critical steps to preventing internal capsule stroke and hemiparesis. The transcortical approach and intraoperative mapping are useful tools to maximize safety.

CONCLUSIONS The insula’s proximity to middle cerebral and lenticulostriate arteries, primary motor areas, and perisyl- vian language areas makes accessing and resecting gliomas in this region challenging. Maximal safe resection of insular gliomas not only is possible but also is associated with excellent outcomes and should be considered for all patients with low- and high-grade gliomas in this area.

Subcutaneous bone flap storage after emergency craniectomy: cost-effectiveness and rate of resorption

J Neurosurg 129:1604–1610, 2018

Decompressive craniectomy is used for uncontrolled intracranial pressure in traumatic brain injury and malignant hemispheric stroke. Subcutaneous preservation of the autologous bone flap in the abdomen is a simple, portable technique but has largely been abandoned due to perceived concerns of resorption. The authors sought to characterize their experience with subcutaneous preservation of the bone flap and cranioplasty.

METHODS The authors performed a retrospective single-institution review of subcutaneous preservation of the autologous bone flap after decompressive craniectomy from 2005 to 2015. The primary outcome was clinically significant bone resorption, defined as requiring a complete mesh implant at the time of cranioplasty, or delayed revision. The outcome also combined cases with any minor bone resorption to determine predictors of this outcome. Logistic regression modeling was used to determine the risk factors for predicting resorption. A cost comparison analysis was also used via the 2-sided t-test to compare the cost of cranioplasty using an autologous bone flap with standard custom implant costs.

RESULTS A total of 193 patients with craniectomy were identified, 108 of whom received a cranioplasty. The mean time to cranioplasty was 104.31 days. Severe resorption occurred in 10 cases (9.26%): 4 were clinically significant (2 early and 2 late) and 6 demonstrated type II (severe) necrosis on CT, but did not require revision. Early resorption of any kind (mild or severe) occurred in 28 (25.93%) of 108 cases. Of the 108 patients, 26 (24.07%) required supplemental cranioplasty material. Late resorption of any kind (mild or severe) occurred in 6 (5.88%) of 102 cases. Of these, a clinically noticeable but nonoperative deformity was noted in 4 (3.92%) and minor (type I) necrosis on CT in 37 (37%) of 100. Bivariate analysis identified fragmentation of bone (OR 3.90, 95% CI 1.03–14.8), shunt-dependent hydrocephalus (OR 7.97, 95% CI 1.57–40.46), and presence of post-cranioplasty drain (OR 9.39, 95% CI 1.14–1000) to be significant risk factors for bone resorption. A binary logistic regression optimized using Fisher’s scoring determined the optimal multivariable combination of factors. Fragmentation of bone (OR 5.84, 95% CI 1.38–28.78), diabetes (OR 7.61, 95% CI 1.37–44.56), and shunt-dependent hydrocephalus (OR 9.35, 95% CI 1.64–56.21) were found to be most predictive of resorption, with a C value of 0.78. Infections occurred in the subcutaneous pocket in 5 (2.60%) of the 193 cases and after cranioplasty in 10 (9.26%) of the 108 who underwent cranioplasty. The average cost of cranioplasty with autologous bone was $2156.28 ± $1144.60 (n = 15), and of a custom implant was $35,118.60 ± $2067.51 (3 different sizes; p < 0.0001).

CONCLUSIONS Craniectomy with autologous bone cranioplasty using subcutaneous pocket storage is safe and compares favorably to cryopreservation in terms of resorption and favorably to a custom synthetic implant in terms of cost. While randomized data are required to definitively prove the superiority of one method, subcutaneous preservation has enough practical advantages with low risk to warrant routine use for most patients.

 

Novel Temporary Treatment for a Severe Case of Syndrome of Trephined

World Neurosurg. (2018) 120:200-204

Syndrome of the trephined is a unique neurosurgical condition that is seen in patients that have undergone craniectomy. While the symptoms of the condition range from mild to severe, the only definitive treatment for the condition is replacement of the bone flap. This article presents a novel, temporary treatment for syndrome of the trephined in a patient with severe symptoms who was unable to undergo immediate cranioplasty due to infection.

CASE DESCRIPTION: A 25-year-old gentleman with a history of trauma resulting in hydrocephalus, craniectomy, and eventually ventriculoperitoneal shunt placement presented with a cranial wound infection requiring removal of his bone flap. While being treated with antibiotics, with his bone flap removed, he developed severe syndrome of the trephined. An emergency bedside procedure was developed and executed to treat his condition.

CONCLUSIONS: Treating syndrome of the trephined with an external suction device proved useful and lifesaving fort the patient presented. Such a device can be made with common supplies found within any hospital. The technique used to treat the patient is novel and may be useful for others to consider if ever faced with a similar situation.

Endoscopic transorbital superior eyelid approach: anatomical study from a neurosurgical perspective

J Neurosurg 129:1203–1216, 2017

Recent studies have proposed the superior eyelid endoscopic transorbital approach as a new minimally invasive route to access orbital lesions, mostly in otolaryngology and maxillofacial surgeries. The authors undertook this anatomical study in order to contribute a neurosurgical perspective, exploring the anterior and middle cranial fossa areas through this purely endoscopic transorbital trajectory.

METHODS Anatomical dissections were performed in 10 human cadaveric heads (20 sides) using 0° and 30° endoscopes. A step-by-step description of the superior eyelid transorbital endoscopic route and surgically oriented classification are provided.

RESULTS The authors’ cadaveric prosection of this approach defined 3 modular routes that could be combined. Two corridors using bone removal lateral to the superior and inferior orbital fissures exposed the middle and anterior cranial fossa (lateral orbital corridors to the anterior and middle cranial base) to unveil the temporal pole region, lateral wall of the cavernous sinus, middle cranial fossa floor, and frontobasal area (i.e., orbital and recti gyri of the frontal lobe). Combined, these 2 corridors exposed the lateral aspect of the lesser sphenoid wing with the Sylvian region (combined lateral orbital corridor to the anterior and middle cranial fossa, with lesser sphenoid wing removal). The medial corridor, with extension of bone removal medially to the superior and inferior orbital fissure, afforded exposure of the opticocarotid area (medial orbital corridor to the opticocarotid area).

CONCLUSIONS Along with its minimally invasive nature, the superior eyelid transorbital approach allows good visualization and manipulation of anatomical structures mainly located in the anterior and middle cranial fossae (i.e., lateral to the superior and inferior orbital fissures). The visualization and management of the opticocarotid region medial to the superior orbital fissure are more complex. Further studies are needed to prove clinical applications of this relatively novel surgical pathway.

 

Minimally Invasive Trigeminal Ablation: Novel Transoral Technique for Targeted Treatment of V3

World Neurosurg. (2018) 118:193-196

Trigeminal neuralgia (TN) is a chronic orofacial pain syndrome that presents with debilitating shooting pains in the V3 nerve distribution. The condition is traditionally responsive to anticonvulsant therapy; however, cases that become refractory to medications often require surgical intervention.

CASE DESCRIPTION: We present a case of TN that was treated with minimally invasive trigeminal ablation. The patient presented with a 6-year history of TN that had been resistant to medical management. The patient opted for minimally invasive management, refused stereotactic radiosurgery, and was treated using the minimally invasive trigeminal ablation approach. At 16 weeks postoperatively, the patient reported complete alleviation of pain with minimal sensorineural numbness.

CONCLUSIONS: The endoscopic approach allows for precise targeting through visual guidance, which is ideal in patients undergoing neuroablation for pain within specific nerve distributions. This is the first documented case of an endoscopic minimally invasive transoral approach toward ablative TN management.

Double-barrel STA to proximal MCA bypass and proximal parent artery occlusion for a fusiform superior clinoidal ICA aneurysm

Acta Neurochirurgica (2018) 160:1939–1943

Blood flow replacement and parent artery occlusion are alternative treatments of complex fusiform superior clinoidal ICA aneurysms. While double-barrel STA to proximal MCA bypass is a conventional approach among these reported bypass algorithms, its technical details remain underexplored.

Method We have applied the double-barrel STA to proximal MCA bypass and parent artery occlusion to treat a 45-year-old female patient with a right fusiform superior clinoidal ICA aneurysm. The technical nuances of this approach are reported.

Conclusion We show that double-barrel STA to proximal MCA bypass and proximal parent artery occlusion can be alternative treatments of complex fusiform superior clinoidal ICA aneurysms.

Robot-assisted multi-level anterior lumbar interbody fusion: an anatomical study

Acta Neurochirurgica (2018) 160:1891–189

Minimally invasive surgical approaches still provide limited exposure. Access to the L2–L5 intervertebral discs during a single procedure is challenging and often requires repositioning of the patient and adopting an alternative approach.

Objectives Investigate the windows to the L2–L5 intervertebral discs to assess the dimensions of the interbody implants suitable for the procedure and evaluate the feasibility of multi-level lumbar intervertebral disc surgery in robot-assisted surgery (RAS)

Methods Sixteen fresh-frozen cadaveric specimens underwent a retroperitoneal approach to access the L2–L5 intervertebral discs. The L2–L3 to L4–L5 windows were defined as the distance between the left lateral border of the aorta (or nearest common iliac vessel) and the medial border of the psoas, measured in a static state and after gentle medial retraction of the vascular structures. Two living porcine specimens and one cadaveric specimen underwent da Vinci robot-assisted transperitoneal approach to expose the L2–L3 to L4–L5 intervertebral discs and perform multi-level discectomy and interbody implant placement.

Results The L2–L3 to L4–L5 intervertebral disc windows significantly increased from a static to a retracted state (p < 0.05). The mean L2–L3, L3–L4, and L4–L5 windows measured respectively 20.1, 21.6, and 19.6 mm in the static state, and 27.2, 30.9, and 30.3 mm after gentle vascular retraction. The intervertebral windows from L2–L3 to L4–L5 were successfully exposed through an anterior transperitoneal approach with the da Vinci robot on the cadaveric and living porcine specimens, and interbody implants were inserted.

Conclusion RAS appears to be feasible for a mini-invasive multi-level lumbar intervertebral disc surgery. The RAS procedure, longer and more expensive than conventional MIS approaches, should be reserved for elective patients.

 

Randomized controlled study comparing 2 surgical techniques for decompressive craniectomy: with watertight duraplasty and without watertight duraplasty

J Neurosurg 129:1017–1023, 2018

Decompressive craniectomy (DC) is a widely used procedure in neurosurgery; however, few studies focus on the best surgical technique for the procedure. The authors’ objective was to conduct a prospective randomized controlled trial comparing 2 techniques for performing DC: with watertight duraplasty and without watertight duraplasty (rapid-closure DC).

METHODS The study population comprised patients ranging in age from 18 to 60 years who were admitted to the Neurotrauma Service of the Hospital da Restauração with a clinical indication for unilateral decompressive craniectomy. Patients were randomized by numbered envelopes into 2 groups: with watertight duraplasty (control group) and without watertight duraplasty (test group). After unilateral DC was completed, watertight duraplasty was performed in the control group, while in the test group, no watertight duraplasty was performed and the exposed parenchyma was covered with Surgicel and the remaining dura mater. Patients were then monitored daily from the date of surgery until hospital discharge or death. The primary end point was the incidence of surgical complications (CSF leak, wound infection, brain abscess, or subgaleal fluid collections). The following were analyzed as secondary end points: clinical outcome (analyzed using the Glasgow Outcome Scale [GOS]), surgical time, and hospital costs.

RESULTS Fifty-eight patients were enrolled, 29 in each group. Three patients were excluded, leaving 27 in the test group and 28 in the control group. There were no significant differences between groups regarding age, Glasgow Coma Scale score at the time of surgery, GOS score, and number of postoperative follow-up days. There were 9 surgical complications (5 in the control group and 4 in the test group), with no significant differences between the groups. The mean surgical time in the control group was 132 minutes, while in the test group the average surgical time was 101 minutes, a difference of 31 minutes (p = 0.001). The mean reduction in total cost was $420.00 USD (a 23.4% reduction) per procedure in the test group.

CONCLUSIONS Rapid-closure DC without watertight duraplasty is a safe procedure. It is not associated with a higher incidence of surgical complications (CSF leak, wound infection, brain abscess, or subgaleal fluid collections), and it decreased surgical time by 31 minutes on average. There was also a hospital cost reduction of $420.00 USD (23.4% reduction) per procedure. Clinical trial registration no.: NCT02594137 (clinicaltrials.gov)

 

The eyebrow approach for anterior circle of Willis aneurysms

Acta Neurochirurgica (2018) 160:1749–1753

The eyebrow approach is a keyhole technique that gives a wide access to the anterior circle of Willis.

Methods A 4-cm linear incision is placed in the upper limit of the eyebrow and a small supraorbital bone flap is raised. A wide arachnoid dissection is essential to maximize the working space. One or multiple aneurysms may be treated by the same approach.

Conclusions The eyebrow approach is a safe technique for selected aneurysms of the anterior circle of Willis

Minimally Invasive Brain Port Approach for Accessing Deep-Seated Lesions Using Simple Syringe

World Neurosurg. (2018) 117:54-61

Retraction-related injury is a recognized complication in neurosurgery. Use of tubular retractors that distribute the pressure on brain tissue was introduced to minimize brain injury. We developed a modified technique using a simple plastic syringe with a Foley catheter to achieve atraumatic cannulation in accessing deep lesions.
METHODS: A retrospective pilot study was conducted to assess safety of the syringe transtubular technique for accessing deep lesions as a cost-effective substitute for commercial brain port methods and to identify retractionrelated injury using diffusion-weighted magnetic resonance imaging postoperatively. Nine patients were operated on using the syringe technique. Lesions selected were intraparenchymal, deeply located in the supratentorial compartment. Lesions were located in the insula (n [ 2), thalamus or basal ganglia (n [ 5), subcortical frontoparietal (n [ 1) lobe, and right temporal lobe (n [ 1). Patients with hematomas, intraventricular lesions, superficially located lesions; pediatric patients less than 12 years old; and patients undergoing redo surgeries were excluded.
RESULTS: Surgical goals were achieved in 8 patients. Three patients had transient deficits; one patient had significant morbidity, which was diagnosed postoperatively as toxoplasmosis. Diffusion restriction was noted in all patients at the surgical cavity but not in the cannulation path.
CONCLUSIONS: Transtubular approaches have a good safety profile and can help achieve surgical goals. Larger studies are needed to compare this approach with other methods, including its effect on hospital stay and survival. The syringe technique is an alternative safe method that can be used in certain neurosurgical centers where commercial tube systems are unavailable.