Principles of Pituitary Surgery

Key Points 1. Understand the principles of pituitary surgery including the key-elements of surgical planning and decision-making 2. Identify the technical nuances distinguishing the endoscopic from the microscopic transsphenoidal approach 3. Understand the strategies utilized during the nasal, sphenoidal, and sellar stages of surgery that maximize tumor resection while minimizing complications and preserving sino- nasal anatomy/functio

Prevention and Management of Bleeding During Endoscopic Approaches to Skull Base Pathologies

The rate of serious permanent morbidity and mortality with endonasal approaches has declined secondary to increased knowledge of the pertinent anatomy, advanced neuroimaging and navigation techniques, better surgical instruments, and improved exposure and reconstruction strategies.1-3 Although rare, vascular injury remains a potentially serious complication. However, with limited systematically-collected and reported data, the exact incidence rate of vascular injuries is difficult to determine. In terms of arterial injuries, the incidence based on reported series likely ranges from 0.3%-9% (Table 1),4-11 with higher rates most commonly associated with chordomas and chondrosarcomas involving the clivus. Venous injury is comparatively less severe and easier to manage. As a result, there is a comparatively lower impetus to publish epidemiological data and management strategies for these injuries. The consequences of arterial injury include fatal hemorrhage, vessel occlusion or thromboembolism causing infarction, development of a pseudoaneurysm (PA), carotid-cavernous fistula (CCF), subarachnoid hemorrhage (SAH), and vasospasm.6,7,9 Surgical expertise and detailed knowledge of the neurovascular anatomy is critical to the avoidance and management of vascular injuries. Pages: 20-2

Is Reconstruction of the Sella Necessary to Prevent Optic Chiasm Prolapse and Cerebrospinal Fluid Leakage Following Endoscopic Resection of Pituitary Macroadenomas?

Visual compromise is a common presentation of pituitary macroadenomas and is related to direct optic nerve and chiasm compression. Although the extent of visual recovery following treatment depends on the duration and severity of the visual compromise, the majority of patients experience gradual improvement in their vision. Delayed visual deterioration following treatment is typically related to either tumor recurrence or radiation-induced optic neuropathy, although visual worsening due to prolapse of the optic apparatus into a secondary empty sella has rarely been reported. In 1968, Guiot reported the first a case of reversible visual deterioration associated with optic chiasm prolapse following resection of a large pituitary macroadenoma (Guiot). Based on their observations, Guiot and collaborators recommended that a “prop” be placed in the sella at the time of transsphenoidal pituitary adenoma resection to prevent progressive herniation of the optic structures. Similarly, Hardy coined the term “preventive chiasmopexy” to describe filling of the sella cavity with autologous tissue such as muscle or fat following resection of large tumors to prevent this herniation phenomenon. While optic chiasm prolapse with associated visual deterioration appears to represent a rare occurrence, its true incidence and pathophysiological basis remain uncertain. Reconstruction of the sella with autologous tissues is also widely employed as a means to prevent postoperative cerebrospinal fluid leakage with these tissues typically harvested from a secondary operative site such as the abdomen. Although not frequently reported in the pituitary literature, complications of abdominal fat graft harvest include hematoma and seroma formation as well as infection with an incidence ranging from 1-7%. At our institution, we do not routinely perform dural reconstruction following transsphenoidal resection of pituitary macroadenomas using adipose tissue to prevent cerebrospinal fluid leakage or optic chiasm prolapse. In this study, we sought to determine the incidence of optic chiasm prolapse into the sellar defect by determining the radiographic position of the optic chiasm following surgery and incidence of delayed visual deterioration. Pages: 13-1

Comprehensive Management of the Paranasal Sinuses in Patients Undergoing Endoscopic Endonasal Skull Base Surgery.

OBJECTIVE: The endonasal route often provides the most direct and safe approach to skull base pathology. In this article we review the literature with regard to management of the paranasal sinuses in the setting of skull base surgery. METHODS: We describe our institutional experience and review the literature of concurrent management of the sinusitis in patients undergoing endoscopic skull base surgery. RESULTS: Patients should be optimized preoperatively to ensure the endonasal route is a safe corridor to enter the intracranial cavity. Often the paranasal sinuses can be surgically addressed at the same time as endoscopic skull base surgery. We describe the technical details of management of the paranasal sinuses when addressing skull base pathology. CONCLUSIONS: Careful management of the paranasal sinuses throughout the peri-operative course is paramount to optimizing sinonasal function and safety

Endonasal Vascularized Flaps For Cranial Base Reconstruction

Since the introduction of extended endoscopic cranial base surgery, postoperative cerebrospinal fluid (CSF) leak has been a formidable and troublesome issue resulting in complications such meningitis, pneumocephalus, and the need for additional surgical interventions. Establishment of a watertight cranial base reconstruction is the most critical step in preventing postoperative CSF leakage. Historically, various free grafts, both synthetic and autologous, were utilized as repair materials for reconstruction of the cranial base defect often in combination with temporary CSF diversion. Free grafts are often sufficient for repair of small low flow, low pressure dural defects. High postoperative CSF leak rates reported in the initial endoscopic skull base literature are evidence that free grafts do not provide a reliably competent repair for large defects or direct high-flow CSF leaks. The introduction of the Hadad-Bassagasteguy vascularized nasoseptal flap has significantly reduced the reported CSF leak rate with a recent meta-analysis reporting that use of the vascularized flap is associated with a 7% rate of postoperative CSF leakage compared to 16% with free grafts alone for large dural defects.6 Since the initial description of the vascularized pedicled nasoseptal flap in 2006, many surgeons have developed a variety of alternative vascularized flaps for endonasal cranial base reconstruction. In this article, we summarize and compare several of the most clinically useful vascularized flaps including their harvest technique, indications and limitations, and potential complications. Pages: 28-3

Avoidance of Maxillary Swing for Nasopharyngectomy via Combined Open Lateral and Endoscopic Approach

Objectives: Nasopharyngectomy performed via a solely endoscopic approach has limitations in access and feasibility, particularly regarding management of the carotid artery. To address these limitations, we report three cases with one cadaver dissection where nasopharyngectomy was performed via a combined open lateral an endoscopic approach. We highlight the benefits and technical considerations for this operative technique. Study Design: Case Series Methods: Patients diagnosed with recurrent nasopharyngeal carcinoma (NPC) that underwent combined open lateral and endoscopic nasopharyngectomy from 2016-2020 were analyzed. A cadaver dissection was also performed. Results: We present the details of the approach and follow-up in three patients with recurrent nasopharyngeal carcinoma. Briefly, a preauricular incision is extended down to the neck. The zygoma and mandibular ramus can be removed and replaced if required. V3, the pterygoid plates and the eustachian tube can be resected or mobilized. The carotid artery may be identified proximally in the neck and traced to the skull base, where the carotid canal may be drilled to the level of the foramen lacerum and protected with a pledget. Then, tumor mucosal cuts are made via an endoscopic endonasal approach and connected to the lateral exposure. No carotid artery injuries occurred. Conclusion: The combined open lateral approach and endoscopic nasopharyngectomy technique is a useful technique in salvage patients. It provides excellent control of major vessels, adequate access to the carotid canal, V3, and remainder of the skull base, and cervical protection.https://jdc.jefferson.edu/otoposters/1009/thumbnail.jp

A Comparative Analysis of Anterior & Lateral Cranial Base CSF Leaks

Introduction The optimal strategy for management of Idiopathic Intracranial Hypertension (IIH) in anterior and lateral cranial base meningoencephaloceles remains debated. The purpose of this study is to present a comparison of the surgical management of anterior and lateral cranial base meningoencephalocele and a treatment algorithm for the diagnosis and management of IIH in this patient population. Methods Retrospective study of 109 patients who underwent anterior or lateral CSF leak repair at TJU from 2004-2020. Epic & RedCap were utilized to record data. Patient demographics, presenting symptoms, imaging, Beta-2 Transferring testing, surgery, repair, and post-op data were collected. Two-sided Chi-squared tests and Independent t-test were performed via SPSS Statistics 26. Results 49 anterior cranial base (ACB) and 60 lateral cranial base (LCB) defects were included. Anterior cohort had significantly more women (N=77, 85.7%, p=0.02). Anterior cohort presented with significantly higher multiple leak sites (24.5% vs 15.0%, p=0.036). Six patients, 3 in each cohort, none of whom received Ventriculoperitoneal shunts (VPS) developed recurrence. VPS were placed for long-term CSF diversion in 23 ACB cases (46.9%) and 10 LCB cases (16.7%), (p\u3c0.01). Discussion ACB cases had a higher incidence of females, multiple site leaks, and more likely to undergo VPS placement. No patients developed recurrence after placement of a VPS. Long-term CSF diversion via VPS, in addition to surgical repair, should be considered in patients with elevated intracranial pressure and other high-risk factors to prevent recurrence of CSF leaks

Timing of crystallization of the lunar magma ocean constrained by the oldest zircon

The Moon is thought to have formed through the consolidationof debris from the collision of a Mars-sized body with the Earthmore than 4,500 million years ago. The primitive Moon wascovered with a thick layer of melt known as the lunar magmaocean1, the crystallization of which resulted in the Moon?ssurface as it is observed today. There is considerable debate,however, over the precise timing and duration of the processof magma ocean crystallization. Here we date a zircon fromlunar breccias to an age of 4,4176 million years. This dateprovides a precise younger age limit for the solidification ofthe lunar magma ocean. We propose a model that suggestsan exponential rate of lunar crystallization, based on acombination of this oldest known lunar zircon and the age of theMoon-forming giant impact. We conclude that the formationof the Moon?s anorthositic crust followed the solidification of80?85% of the original melt, within about 100 million years ofthe collision. The existence of younger zircons2 is indicative ofthe continued solidification of a small percentage of melt for anextra 200?400 million years

CCR2-V64I polymorphism is associated with increased risk of cervical cancer but not with HPV infection or pre-cancerous lesions in African women

<p>Abstract</p> <p>Background</p> <p>Cervical cancer, caused by specific oncogenic types of human papillomavirus (HPV), is the second most common cancer in women worldwide. A large number of young sexually active women get infected by HPV but only a small fraction of them have persistent infection and develop cervical cancer pointing to co- factors including host genetics that might play a role in outcome of the HPV infection. This study investigated the role of <it>CCR2-V64I </it>polymorphism in cervical cancer, pre-cancers and HPV infection in South African women resident in Western Cape. <it>CCR2-V64I </it>polymorphism has been previously reported to influence the progression to cervical cancer in some populations and has also been associated with decreased progression from HIV infection to AIDS.</p> <p>Methods</p> <p>Genotyping for <it>CCR2-V64I </it>was done by PCR-SSP in a case-control study of 446 women (106 black African and 340 mixed-ancestry) with histologically confirmed invasive cervical cancer and 1432 controls (322 black African and 1110 mixed-ancestry) group-matched (1:3) by age, ethnicity and domicile status. In the control women HPV was detected using the Digene Hybrid Capture II test and cervical disease was detected by cervical cytology.</p> <p>Results</p> <p>The <it>CCR2-64I </it>variant was significantly associated with cervical cancer when cases were compared to the control group (P = 0.001). Further analysis comparing selected groups within the controls showed that individuals with abnormal cytology and high grade squamous intraepitleial neoplasia (HSIL) did not have this association when compared to women with normal cytology. HPV infection also showed no association with <it>CCR2-64I </it>variant. Comparing SIL positive controls with the cases showed a significant association of <it>CCR2-64I </it>variant (P = 0.001) with cervical cancer.</p> <p>Conclusions</p> <p>This is the first study of the role of <it>CCR2-V64I </it>polymorphism in cervical cancer in an African population. Our results show that <it>CCR2-64I </it>variant is associated with the risk of cervical cancer but does not affect the susceptibility to HPV infection or HSIL in South African women of black and mixed-ancestry origin. This result implies that the role of CCR2 is important in invasive cancer of the cervix but not in HPV infection or in the development of pre-cancers.</p