Extended endoscopic endonasal approaches have allowed for a minimally invasive solution for removal of a variety of ventral skull base lesions, including intradural tumors. Depending on the location of the pathological entity, various types of surgical corridors are used, such as transcribriform, transplanum transtuberculum, transsellar, transclival, and transodontoid approaches. Often, a large skull base dural defect with a high-flow CSF leak is created after endoscopic skull base surgery. Successful reconstruction of the cranial base defect is paramount to separate the intracranial contents from the paranasal sinus contents and to prevent postoperative CSF leakage. The vascularized pedicled nasoseptal flap (PNSF) has become the workhorse for cranial base reconstruction after endoscopic skull base surgery, dramatically reducing the rate of postoperative CSF leakage since its implementation. In this report, the authors review the surgical technique and describe the operative nuances and lessons learned for successful multilayered PNSF reconstruction of cranial base defects with high-flow CSF leaks created after endoscopic skull base surgery. The authors specifically highlight important surgical pearls that are critical for successful PNSF reconstruction, including target-specific flap design and harvesting, pedicle preservation, preparation of bony defect and graft site to optimize flap adherence, multilayered closure technique, maximization of the reach of the flap, final flap positioning, and proper bolstering and buttressing of the PNSF to prevent flap dehiscence. Using this technique in 93 patients, the authors' overall postoperative CSF leak rate was 3.2%. An illustrative intraoperative video demonstrating the reconstruction technique is also presented.
James K. Liu, Richard F. Schmidt, Osamah J. Choudhry, Pratik A. Shukla, and Jean Anderson Eloy
Richard F. Schmidt, Frederick Yick, Zain Boghani, Jean Anderson Eloy, and James K. Liu
Malignant peripheral nerve sheath tumors (MPNSTs) are a rare form of malignancy arising from the Schwann cells of peripheral nerves. MPNSTs of the trigeminal nerve are exceptionally rare, with only a handful of reports in the literature. These tumors are typically very aggressive, resulting in significant patient morbidity and a generally grim prognosis. Most current reports suggest that radical resection with radiation therapy offers the best benefit. In this study, the authors systematically reviewed the world English-language literature on MPNSTs of the trigeminal nerve to analyze the presentations, treatment options, and outcomes for patients with this disease.
A literature search for MPNSTs of the trigeminal nerve confined to nonanimal, English-language articles was conducted utilizing the PubMed database, with additional cases chosen from the references of selected articles. Only cases of confirmed MPNSTs of the trigeminal nerve or its peripheral branches, based upon surgical, pathological, or radiological analysis, were included.
From the literature search, 29 articles discussing 35 cases of MPNSTs of the trigeminal nerve were chosen. With the addition of 1 case from their own institution, the authors analyzed 36 cases of trigeminal MPNSTs. The average age of onset was 44.6 years. These tumors were more commonly seen in male patients (77.1%). The gasserian ganglion was involved in 36.1% of the cases. Of the cases in which the nerve distribution was specified (n = 25), the mandibular branch was most commonly involved (72.0%), followed by the maxillary branch (60.0%) and the ophthalmic branch (32.0%), with 44.0% of patients exhibiting involvement of 2 or more branches. Altered facial sensation and facial pain were the 2 most commonly reported symptoms, found in 63.9% and 52.8% of patients, respectively. Mastication difficulty and diplopia were seen in 22.2% of patients, facial weakness was seen in 19.4%, and hearing loss was present in 16.7%. With regard to the primary treatment strategy, 80.6% underwent resection, 16.7% underwent radiation therapy, and 2.9% received chemotherapy alone. Patients treated with complete resection followed by postoperative radiation therapy had the most favorable outcomes, with no patients showing evidence of disease recurrence with a mean follow-up of 34.6 months. Patients treated with incomplete resection followed by postoperative radiation therapy had more favorable outcomes than patients treated with incomplete resection without radiation therapy or radiation therapy alone.
Trigeminal MPNSTs most commonly present as altered facial sensation or facial pain, although they exhibit a number of other clinical manifestations, including the involvement of other cranial nerves. While a variety of treatment options exist, due to their highly infiltrative nature, aggressive resection followed by radiation therapy appears to offer the greatest chance of recurrence-free survival.
Richard H. Schmidt, Lisa A. Rietz, Bhupendra C. K. Patel, Anne G. Osborne, David Pratt, and Kathleen B. Digre
✓ Compressive optic neuropathy with acute or chronic vision loss has been associated with various skull base tumors, aneurysms, Graves disease, trauma, and, less commonly, fibrous dysplasia and osteopetrosis. The authors present a case of acute visual deterioration in a 25-year-old woman who had massive calvarial hypertrophy with optic canal stenosis secondary to renal osteodystrophy (uremic leontiasis ossea [ULO]: bighead disease). Significant visual field restoration was achieved with high-dose corticosteroids followed by optic nerve decompression. This is the first case report of cranial neuropathy associated with ULO.
Richard F. Schmidt, Osamah J. Choudhry, Ramya Takkellapati, Jean Anderson Eloy, William T. Couldwell, and James K. Liu
A little over a century ago, in 1907, at the University of Innsbruck, Hermann Schloffer performed the first transsphenoidal surgery on a living patient harboring a pituitary adenoma. Schloffer used a superior nasal route via a transfacial lateral rhinotomy incision. This was perhaps his greatest academic contribution to neurosurgery. Despite the technological limitations of that time, Schloffer's operation was groundbreaking in that it laid the foundation for future development and refinement of transsphenoidal pituitary surgery, influencing prominent surgeons such as Oskar Hirsch and Harvey Cushing. Even after undergoing multiple modifications and a brief fall into obscurity, the transsphenoidal approach has endured through generations of surgeons and remains the preferred approach for lesions of the sella turcica to this day. Although Schloffer performed primarily abdominal surgery in his practice, his contributions to the transsphenoidal approach have had a lasting impact in the field of pituitary and skull base surgery. The authors review the life and career of Hermann Schloffer, the surgical details of his transsphenoidal operation, and the legacy that it has left on the field of pituitary surgery.
Richard F. Schmidt, Osamah J. Choudhry, Joseph Raviv, Soly Baredes, Roy R. Casiano, Jean Anderson Eloy, and James K. Liu
Lateral sphenoid encephaloceles of the Sternberg canal are rare entities and usually present with spontaneous CSF rhinorrhea. Traditionally, these were treated via transcranial approaches, which can be challenging given the deep location of these lesions. However, with advancements in endoscopic skull base surgery, including improved surgical exposures, angled endoscopes and instruments, and novel repair techniques, these encephaloceles can be resected and successfully repaired with purely endoscopic endonasal approaches. In this report, the authors review the endoscopic endonasal transpterygoid approach to the lateral recess of the sphenoid sinus for repair of temporal lobe encephaloceles, including an overview of the surgical anatomy from an endoscopic perspective, and describe the technical operative nuances and surgical pearls for these cases. The authors also present 4 new cases of lateral sphenoid recess encephaloceles that were successfully treated using this approach.
Jennifer L. O. Merrimen, P. Daniel McNeely, Richard L. Bendor-Samuel, Matthias H. Schmidt, and Robert B. Fraser
✓Amniotic band sequence is a disruption sequence having a broad spectrum of clinical manifestations ranging from partial amputations to major craniofacial and limb–body wall defects. Most reported cases of placental–cerebral adhesion pertain to patients with severe craniofacial defects who were either stillborn or who died a few hours after birth. The authors present a case of a male infant born with a placental–cerebral adhesion through a cranial defect. This adhesion was separated at birth, and duraplasty and primary scalp closure were performed. A detailed examination of the placenta revealed the presence of multiple amniotic bands. The case demonstrates that survival and normal early postnatal development are possible if the condition is treated promptly.
Richard F. Schmidt, Zain Boghani, Osamah J. Choudhry, Jean Anderson Eloy, Robert W. Jyung, and James K. Liu
With the relatively recent increase in the use of MRI techniques, there has been a concurrent rise in the number of vestibular schwannomas (VSs) detected as incidental findings. These incidental VSs may be prevalent in up to 0.02%–0.07% of individuals undergoing MRI and represent a significant portion of all diagnosed VSs. The management of these lesions poses a significant challenge for practitioners. Most incidental VSs tend to be small and associated with minimal symptoms, permitting them to be managed conservatively at the time of diagnosis. However, relatively few indicators consistently predict tumor growth and patient outcomes. Furthermore, growth rates have been shown to vary significantly over time with a large variety of long-term growth patterns. Thus, early MRI screening for continued tumor growth followed by repeated MRI studies and clinical assessments throughout the patient's life is an essential component in a conservative management strategy. Note that tumor growth is typically associated with a worsening of symptoms in patients who undergo conservative management, and many of these symptoms have been shown to significantly impact the patient's quality of life. Specific indications for the termination of conservative management vary across studies, but secondary intervention has been shown to be a relatively safe option in most patients with progressive disease. Patients with incidental VSs will probably qualify for a course of conservative management at diagnosis, and regular imaging combined with the expectation that the tumor and symptoms may change at any interval is crucial to ensuring positive long-term outcomes in these patients. In this report, the authors discuss the current literature pertaining to the prevalence of incidental VSs and various considerations in the management of these lesions. It is hoped that by incorporating an understanding of tumor growth, patient outcomes, and management strategies, practitioners will be able to effectively address this challenging disease entity.
Omaditya Khanna, Lohit Velagapudi, Somnath Das, Ahmad Sweid, Nikolaos Mouchtouris, Fadi Al Saiegh, Michael B. Avery, Nohra Chalouhi, Richard F. Schmidt, Kalyan Sajja, M. Reid Gooch, Stavropoula Tjoumakaris, Robert H. Rosenwasser, and Pascal M. Jabbour
In this study, the authors aimed to investigate procedural and clinical outcomes between radial and femoral artery access in patients undergoing thrombectomy for acute stroke.
The authors conducted a single-institution retrospective analysis of 104 patients who underwent mechanical thrombectomy, 52 via transradial access and 52 via traditional transfemoral access. They analyzed various procedural and clinical metrics between the two patient cohorts.
There was no difference between patient demographics or presenting symptoms of stroke severity between patients treated via transradial or transfemoral access. The mean procedural time was similar between the two treatment cohorts: 60.35 ± 36.81 minutes for the transradial group versus 65.50 ± 29.92 minutes for the transfemoral group (p = 0.451). The mean total fluoroscopy time for the procedure was similar between the two patient cohorts (20.31 ± 11.68 for radial vs 18.49 ± 11.78 minutes for femoral, p = 0.898). The majority of patients underwent thrombolysis in cerebral infarction score 2b/3 revascularization, regardless of access site (92.3% for radial vs 94.2% for femoral, p = 0.696). There was no significant difference in the incidence of access site or periprocedural complications between the transradial and transfemoral cohorts.
Acute stroke intervention performed via transradial access is feasible and effective, with no significant difference in procedural and clinical outcomes compared with traditional transfemoral access. Larger studies are required to further validate the efficacy and limitations of transradial access for neurointerventional procedures.
Jian Guan, Michael Karsy, Andrea A. Brock, William T. Couldwell, John R. W. Kestle, Randy L. Jensen, Andrew T. Dailey, Erica F. Bisson, and Richard H. Schmidt
Overlapping surgery remains a controversial topic in the medical community. Although numerous studies have examined the safety profile of overlapping operations, there are few data on its financial impact. The authors assessed direct hospital costs associated with neurosurgical operations during periods before and after a more stringent overlapping surgery policy was implemented.
The authors retrospectively reviewed the records of nonemergency neurosurgical operations that took place during the periods from June 1, 2014, to October 31, 2014 (pre–policy change), and from June 1, 2016, to October 31, 2016 (post–policy change), by any of the 4 senior neurosurgeons authorized to perform overlapping cases during both periods. Cost data as well as demographic, surgical, and hospitalization-related variables were obtained from an institutional tool, the Value-Driven Outcomes database.
A total of 625 hospitalizations met inclusion criteria for cost analysis; of these, 362 occurred prior to the policy change and 263 occurred after the change. All costs were reported as a proportion of the average total hospitalization cost for the entire cohort. There was no significant difference in mean total hospital costs between the prechange and postchange period (0.994 ± 1.237 vs 1.009 ± 0.994, p = 0.873). On multivariate linear regression analysis, neither the policy change (p = 0.582) nor the use of overlapping surgery (p = 0.273) was significantly associated with higher total hospital costs.
A more restrictive overlapping surgery policy was not associated with a reduction in the direct costs of hospitalization for neurosurgical procedures.
Nikolaos Mouchtouris, Fadi Al Saiegh, Evan Fitchett, Carrie E. Andrews, Michael J. Lang, Ritam Ghosh, Richard F. Schmidt, Nohra Chalouhi, Guilherme Barros, Hekmat Zarzour, Victor Romo, Nabeel Herial, Pascal Jabbour, Stavropoula I. Tjoumakaris, Robert H. Rosenwasser, and M. Reid Gooch
The advent of mechanical thrombectomy (MT) has become an effective option for the treatment of acute ischemic stroke in addition to tissue plasminogen activator (tPA). With recent advances in device technology, MT has significantly altered the hospital course and functional outcomes of stroke patients. The authors’ goal was to establish the most up-to-date reperfusion and functional outcomes with the evolution of MT technology.
The authors conducted a retrospective study of 403 patients who underwent MT for ischemic stroke at their institution from 2010 to 2017. They collected data on patient comorbidities, National Institutes of Health Stroke Scale (NIHSS) score on arrival, tPA administration, revascularization outcomes, and functional outcomes on discharge.
In 403 patients, the mean NIHSS score on presentation was 15.8 ± 6.6, with 195 (48.0%) of patients receiving tPA prior to MT. Successful reperfusion (thrombolysis in cerebral infarction score 2B or 3) was achieved in 84.4%. Hemorrhagic conversion with significant mass effect was noted in 9.9% of patients. The median lengths of ICU and hospital stay were 3.0 and 7.0 days, respectively. Functional independence (modified Rankin Scale score 0–2) was noted in 125 (31.0%) patients, while inpatient mortality occurred in 43 (10.7%) patients.
As MT has established acute ischemic stroke as a neurosurgical disease, there is a pressing need to understand the hospital course, hospital- and procedure-related complications, and outcomes for this new patient population. The authors provide a detailed account of key metrics for MT with the latest device technology and identify the predictors of unfavorable outcomes and inpatient mortality.