Immediate complications associated with high-flow cerebrospinal fluid egress during endoscopic endonasal skull base surgery

Subgaleal drain versus dissection of subgaleal space and closure without drain after burr-hole drainage of chronic subdural hematoma

Background

Chronic subdural hematoma (CSDH) is a collection of blood, blood degradation products, and fluid that accumulate on the surface of the brain between its arachnoid and dural coverings. This study is to evaluate the efficacy of subgaleal drain (SGD) versus subgaleal dissection without drainage as adjuncts to burr-hole evacuation of CSDH.

Methods

A retrospective study was conducted utilizing the data of 60 patients operated for symptomatic CSDH. Patients were divided into two groups, each thirty consecutive patients: Group I, in which a SGD was inserted after CSDH evacuation through a burr-hole; and Group II, the hematoma was evacuated as in the Group I, but with no SGD insertion but instead a subgaleal pocket was created for drainage.

Results

The neurological improvement at 24 h, discharge, 2 weeks, and 6 months after surgery was comparable in both groups. The overall recurrence was 4 cases (4/60, 6.7%). The rate of recurrence and surgical infection rate were comparable in both groups. Both groups showed similar incidences of postoperative seizures, bleeding, rates of medical complications, and neurological deficits. The overall postoperative mortality was five cases (5/60, 8.3%) with no significant difference between groups.

Conclusion

Blunt dissection to open the subgaleal space and closure without a drain is a safe and efficient alternative to the insertion of a drain after the burr-hole evacuation of CSDH.

Endoscopic Endonasal Skull Base Surgery Complication Avoidance: A Contemporary Review

The endoscopic endonasal approach (EEA) provides a direct trajectory to ventral skull base lesions, avoidance of brain retraction, and clear visualization of cranial nerves as they exit skull base foramina. Despite these benefits, the EEA is not without complications. Here, we review published literature highlighting complications associated with the EEA including cerebrospinal fluid (CSF) leak, cranial nerve (CN) dysfunction, pituitary gland dysfunction, internal carotid artery (ICA) injury, infection, and others; we place special emphasis on discussing the prevention of these complications. As widespread adoption of the EEA continues, it becomes critical to educate surgeons regarding potential complications and their prevention while identifying gaps in the current literature to guide future research and advances in clinical care.

Chronic Subdural Hematoma (cSDH): A review of the current state of the art

Introduction

Incidence of Chronic Subdural Hematoma (cSDH) is rising worldwide, partly due to an aging population, but also due to increased use of antithrombotic medication. Many recent studies have emerged to address current cSDH management strategies.

Research question

What is the state of the art of cSDH management.

Material and methods

Review.

Results

Head trauma, antithrombotic use and craniocerebral disproportion increase the risk of cSDH development. Most patients present with disorientation, GCS 13–15, and symptoms arising from cortical irritation and increased intracranial pressure. cSDH occurs bilaterally in 9–22%. CT allows assessment of cerebral compression (herniation, hematoma thickness, ventricle collapse, midline shift), hematoma age and presence of membranes, factors that ultimately determine treatment urgency and surgical approach. Recurrence remains the principle complication (9–33%), occurring more commonly with older age and bilateral cSDHs.

Discussion and conclusion

While incompletely understood, it is generally believed that injury in the dural cell layer results in bleeding from bridging veins, resulting in a hematoma formation, with or without a preceding hygroma, in a potential space approximating the junction between the dura and arachnoid. Neovascularization and leaking from the outer membrane are thought to propagate this process. Evidence that MMA embolization may reduce recurrence rates is a potentially exciting new treatment option, but also supports the theory that the MMA is implicated in the cSDH pathophysiology. The use of steroids remains a controversial topic without clear treatment guidelines. cSDH represents a common neurosurgical problem with burr-hole treatment remaining the gold standard, often in conjunction with subgaleal drains. MMA embolization to stop recurrence may represent an important evolution in understanding the pathophysiology of cSDH and improving treatment.

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Incidence of cSDH is rising, partly due to the aging population and increased antithrombotic use.

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cSDH occurs bilaterally in 9–22% of cases.

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Recurrence remains the principle complication and has been estimated at 9–33%.

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Risk factors for recurrence include old age and bilateral cSDHs.

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MMA embolization may reduce recurrence, but its efficacy and target population remain unclear.

Tension Pneumocephalus from Positive Pressure Ventilation Following Endoscopic Skull Base Surgery: Case Series and an Institutional Protocol for the Management of Postoperative Respiratory Distress

BACKGROUND

Tension pneumocephalus (TP) is a rare but feared complication of endoscopic endonasal skull base surgery. In contrast to simple pneumocephalus, which is common after endoscopic transnasal approaches and managed conservatively, TP represents a neurosurgical emergency and mandates urgent decompression.

CASE DESCRIPTION

Here we present 2 cases of TP as a consequence of positive pressure ventilation following endoscopic endonasal skull base surgery. Both occurred during resuscitation for postoperative hypoxia. These cases prompted the development of an institution-wide protocol to identify and manage patients at risk of TP after extended skull base approaches.

CONCLUSIONS

To our knowledge, these are the only such cases of postoperative TP following positive pressure ventilation in the literature.

Timing of Postoperative CSF Leak after Endoscopic Skull Base Surgery in Patients with Obstructive Sleep Apnea

Background  There is little data regarding postoperative outcomes of patients with obstructive sleep apnea (OSA) undergoing skull base surgery. The purpose of this study is to determine an association between risk factors and proximity of cerebrospinal fluid (CSF) leak to surgery in patients with OSA undergoing endoscopic skull base surgery. Methods  A retrospective review of neurosurgical inpatients, with and without OSA, at a tertiary care institution from 2002 to 2015 that experienced a postoperative CSF leak after undergoing endoscopic skull base surgery. Results  Forty patients met inclusion criteria, 12 (30%) with OSA. OSA patients had significantly higher body mass index (BMI; median 39.4 vs. 31.7, p  < 0.01) and were more likely to have diabetes (41.7 vs. 10.7%, p  = 0.04) than non-OSA patients; otherwise there were no significant differences in clinical comorbidities. No patients restarted positive pressure ventilation (PPV) in the inpatient setting. The type of repair was not a significant predictor of the time from surgery to leak. Patients with OSA experienced postoperative CSF leak 49% sooner than non-OSA patients (Hazard Ratio 1.49, median 2 vs. 6 days, log-rank p  = 0.20). Conclusion  Patients with OSA trended toward leaking earlier than those without OSA, and no OSA patients repaired with a nasoseptal flap (NSF) had a leak after postoperative day 5. Due to a small sample size this trend did not reach significance. Future studies will help to determine the appropriate timing for restarting PPV in this high risk population. This is important given PPV's significant benefit to the patient's overall health and its ability to lower intracranial pressure.

Impact of obstructive sleep apnea in transsphenoidal pituitary surgery: An analysis of inpatient data

OBJECTIVES/HYPOTHESIS

Although previous studies have reported increased perioperative complications among obstructive sleep apnea (OSA) patients undergoing any surgery requiring general anesthesia, there is a paucity of literature addressing the impact of OSA on postoperative transsphenoidal surgery (TSS) complications. The aim of this study was to analyze postoperative outcomes in transsphenoidal pituitary surgery patients with OSA. Secondarily, we examined patient characteristics and comorbidities.

STUDY DESIGN

Retrospective analysis.

METHODS

The 2002 to 2013 National Inpatient Sample was queried for patients undergoing TSS for pituitary neoplasm. Patients with an additional diagnosis of OSA were identified, and compared to a non-OSA cohort.

RESULTS

There were 17,777 patients identified; 5.0% (N = 889) had an additional diagnosis of OSA. The OSA cohort had more comorbidities including diabetes mellitus, congestive heart failure, chronic pulmonary disease, coagulopathy, hypertension, hypothyroidism, liver disease, obesity, peripheral vascular disease, renal failure, acromegaly, and Cushing's syndrome. Postoperatively, OSA was independently associated with increased risks of tracheostomy (P = .015) and hypoxemia (P < .001), and decreased risk of cardiac complications (P = .034). OSA patients did not have increased rates of cerebrospinal fluid rhinorrhea, diabetes insipidus, reintubation, aspiration pneumonia, infectious pneumonia, thromboembolic complications, or urinary/renal complications. In-hospital mortality rates did not vary between the two cohorts.

CONCLUSIONS

In patients who underwent transsphenoidal pituitary surgery, OSA was associated with higher rates of certain pulmonary and airway complications. OSA was not associated with increased non-pulmonary/airway complications or inpatient mortality, despite older average age and higher comorbidity rates.

LEVEL OF EVIDENCE

2C. Laryngoscope, 128:1027-1032, 2018.

Complication Avoidance in Endoscopic Skull Base Surgery

Endoscopic endonasal approaches to the skull base pathology have developed and evolved dramatically over the past 2 decades, particularly with collaboration between neurosurgery and otolaryngology physicians. These advances have increased significantly the use of such approaches beyond just resection of pituitary adenomas, including a variety of skull base pathologies. As the field has evolved, so has our understanding of the complications accompanying endoscopic skull base surgery, as well as techniques to both avoid and manage these complications. These are discussed here.

Cerebral venous overdrainage: an under-recognized complication of cerebrospinal fluid diversion

Understanding the altered physiology following cerebrospinal fluid (CSF) diversion in the setting of adult hydrocephalus is important for optimizing patient care and avoiding complications. There is mounting evidence that the cerebral venous system plays a major role in intracranial pressure (ICP) dynamics especially when one takes into account the effects of postural changes, atmospheric pressure, and gravity on the craniospinal axis as a whole. An evolved mechanism acting at the cortical bridging veins, known as the “Starling resistor,” prevents overdrainage of cranial venous blood with upright positioning. This protective mechanism can become nonfunctional after CSF diversion, which can result in posture-related cerebral venous overdrainage through the cranial venous outflow tracts, leading to pathological states. This review article summarizes the relevant anatomical and physiological bases of the relationship between the craniospinal venous and CSF compartments and surveys complications that may be explained by the cerebral venous overdrainage phenomenon. It is hoped that this article adds a new dimension to our therapeutic methods, stimulates further research into this field, and ultimately improves our care of these patients.

Subtemporal Retrolabyrinthine (Posterior Petrosal) versus Endoscopic Endonasal Approach to the Petroclival Region: An Anatomical and Computed Tomography Study

Background The petroclival region seats many neoplasms. Traditional surgical corridors to the region can result in unacceptable patient morbidity. The combined subtemporal retrolabyrinthine transpetrosal (posterior petrosal) approach provides adequate exposure with hearing preservation; however, the facial nerve and labyrinth are put at risk. Approaching the petroclival region with an endoscopic endonasal approach (EEA) could minimize morbidity. Objective To provide an anatomical and computed tomography (CT) comparison between the posterior petrosal approach and EEA to the petroclival region. Methods The petroclival region was approached transclivally with EEA. Different aspects of dissection were compared with the posterior petrosal approach. The two approaches were also studied using CT analysis. Results A successful corridor medial to the internal auditory canal (IAC) was achieved with EEA. Wide exposure was achieved with no external skin incisions, although significant sinonasal resection was required. The posterior petrosal was comparable in terms of exposure medially; however, the dissection involved more bone removal, greater skill, and a constricting effect upon deeper dissection. Importantly, access lateral to the IAC was obtained, whereas EEA could not reach this area. Conclusion An EEA to the petroclival region is feasible. This approach can be considered in lesions medial to the IAC.

The cerebral venous system and the postural regulation of intracranial pressure: implications in the management of patients with cerebrospinal fluid diversion

Loss of cerebrospinal fluid (CSF) occurs commonly in daily neurosurgical practice. Understanding the altered physiology following CSF loss is important for optimization of patient care and avoidance of complications. There is overwhelming evidence now that the cerebral venous system plays a major role in intracranial pressure (ICP) dynamics especially when one takes into account the effects of postural changes, atmospheric pressure, and gravity on the craniospinal axis as a whole. The CSF and cerebral venous compartments are tightly coupled in two important ways. CSF is resorbed into the venous system, and there is also an evolved mechanism that prevents overdrainage of venous blood with upright positioning known as the Starling resistor. With loss of CSF pressure, this protective mechanism could become nonfunctional which may result in posture-related venous overdrainage through the cranial venous outflow tracts leading to pathologic states. This review article summarizes the relevant anatomic and physiologic basis of the relationship between the craniospinal venous and CSF compartments in the setting of CSF diversion. It is hoped that this article improves our understanding of ICP dynamics after CSF loss, adds a new dimension to our therapeutic methods, stimulates further research into this field, and ultimately improves our care of these patients.

Risk of post-operative pneumocephalus in patients with obstructive sleep apnea undergoing transsphenoidal surgery

Patients undergoing transsphenoidal surgery (TSS) have an anterior skull base defect that limits the use of positive pressure ventilation post-operatively. Obstructive sleep apnea (OSA) can be seen in these patients and is treated with continuous positive airway pressure (CPAP). In our study we documented the incidence of pre-existing OSA and reported the incidence of diagnosed pneumocephalus and its relationship to OSA. A retrospective review was conducted from a surgical outcomes database. Electronic medical records were reviewed, with an emphasis on diagnosis of OSA and documented symptomatic pneumocephalus. A total of 324 patients underwent 349 TSS for sellar mass resection. The average body mass index of the study cohort was 32.5kg/m(2). Sixty-nine patients (21%) had documented OSA. Only 25 out of 69 (36%) had a documented post-operative CPAP plan. Out of all 349 procedures, there were two incidents of pneumocephalus diagnosed. Neither of the patients had pre-existing OSA. One in five patients in our study had pre-existing OSA. Most patients returned to CPAP use within several weeks of TSS for resection of a sellar mass. Neither of the patients with pneumocephalus had pre-existing OSA and none of the patients with early re-initiation of CPAP developed this complication. This study provides preliminary evidence that resuming CPAP early in the post-operative period might be less dangerous than previously assumed.