Immediate postoperative imaging after uncomplicated endoscopic approach to the anterior skull base: is it necessary?

Conventional clinical signs and symptoms are poor predictors of postoperative cerebrospinal fluid leak: A single-centre cohort perspective

BACKGROUND

Postoperative cerebrospinal fluid (CSF) leak remains a concerning complication of the endoscopic endonasal approach (EEA) for skull base pathology. Signs and symptoms suggesting CSF leak often trigger additional workup during the postoperative course. We systematically evaluate associations between subjectively reported clinical signs/symptoms noted during the immediate postoperative period and incidence of postoperative CSF leaks.

METHODS

Retrospective chart review was conducted at a tertiary academic medical centre including 137 consecutive patients with intraoperative CSF leak during EEA with primary repair between July 2018 and August 2022. Postoperative CSF leak associations with clinical signs and symptoms were evaluated using positive (PPV) and negative predictive values (NPV), sensitivity, specificity and odds ratio (OR) via univariate logistic regression.

RESULTS

Seventy-nine patients (57.7%) had high-flow leaks repaired and 5 (3.6%) developed CSF leaks postoperatively. Of reported symptoms, rhinorrhea was most common (n = 52, 38.0%; PPV [95% CI] = 7.6% [4.8%, 11.9%]), followed by severe headache (n = 47, 34.3%; 6.3% [3.1%, 12.5%]), dizziness (n = 43, 31.4%; 2.3% [0.4%, 12.1%]), salty or metallic taste (n = 20, 14.6%; 9.9% [3.3%, 25.8%]), and throat drainage (n = 10, 7.3%; 9.9% [1.7%, 41.4%]). Nausea or vomiting constituted the most reported sign concerning for CSF leak (n = 73, 53.3%; PPV [95% CI] = 4.1% [2.0%, 8.1%]). On univariate regression, no sign or symptom, including rhinorrhea (OR [95% CI] = 7.00 [0.76-64.44]), throat drainage (3.42 [0.35-33.86]), salty/metallic taste (4.22 [0.66-27.04]), severe headache (3.00 [0.48-18.62]), dizziness (0.54 [0.06-4.94]), fever (3.16 [0.50-19.99]), and nausea/vomiting (1.33 [0.22-8.21]), associated with postoperative CSF leak.

CONCLUSIONS

A range of subjectively reported symptoms and signs failed to predict postoperative CSF leak. Further investigation is warranted to inform appropriate attention and response.

Clinical Utility of Routine Postprocedural Computed Tomography of the Head Following Elective Neuroendovascular Interventions

BACKGROUND

Little evidence supports acquisition of routine head imaging after uncomplicated elective neurosurgical procedures for patients with unchanged neurological examinations; however, imaging is still performed by some neurointerventionalists. We assessed the clinical utility of routine computed tomography of the head (CTH) following elective neuroendovascular interventions, including aneurysm coiling, aneurysm stent-assisted coiling, aneurysm flow diversion, arteriovenous malformation/fistula embolization, middle meningeal artery embolization for subdural hematoma, extracranial carotid artery stenting, and venous sinus stenting.

METHODS

Retrospective chart review identified patients undergoing neuroendovascular intervention from 2011 to 2021 at our institution. Demographic, clinical, and radiographic variables, including presenting signs and symptoms, antiplatelets and/or anticoagulant medications, intraprocedural complications, postprocedural CTH findings, and postprocedural neurological examinations, were recorded. Association of clinical variables with an abnormal postprocedural CTH was assessed with univariate analysis. Patients with ruptured vascular pathology, preoperative embolizations, and missing postprocedural CTH images and/or reports were excluded.

RESULTS

Of 509 procedures identified, 354 were eligible for analysis; 4.8% of patients (17/354) had abnormal findings on postprocedural CTH. Nine patients had intraprocedural complications or new postprocedural neurological deficits that would have prompted imaging regardless of institutional practice. None of the remaining 8 (2.3%) patients required additional procedures. New postprocedural neurological deficit was the only significant predictor of abnormal postprocedural CTH (odds ratio = 6.79; 95% confidence interval, 2.01-20.32; P = 0.0009).

CONCLUSIONS

In a large cohort of patients undergoing elective neuroendovascular intervention, no patients were identified for whom routine postprocedural CTH alone meaningfully altered their clinical care. Routine CTH is not necessary after uncomplicated elective neuroendovascular interventions performed with careful postprocedural neurological assessment.

Characterizing and quantifying low-value diagnostic imaging internationally: a scoping review

BACKGROUND

Inappropriate and wasteful use of health care resources is a common problem, constituting 10-34% of health services spending in the western world. Even though diagnostic imaging is vital for identifying correct diagnoses and administrating the right treatment, low-value imaging-in which the diagnostic test confers little to no clinical benefit-is common and contributes to inappropriate and wasteful use of health care resources. There is a lack of knowledge on the types and extent of low-value imaging. Accordingly, the objective of this study was to identify, characterize, and quantify the extent of low-value diagnostic imaging examinations for adults and children.

METHODS

A scoping review of the published literature was performed. Medline-Ovid, Embase-Ovid, Scopus, and Cochrane Library were searched for studies published from 2010 to September 2020. The search strategy was built from medical subject headings (Mesh) for Diagnostic imaging/Radiology OR Health service misuse/Medical overuse OR Procedures and Techniques Utilization/Facilities and Services Utilization. Articles in English, German, Dutch, Swedish, Danish, or Norwegian were included.

RESULTS

A total of 39,986 records were identified and, of these, 370 studies were included in the final synthesis. Eighty-four low-value imaging examinations were identified. Imaging of atraumatic pain, routine imaging in minor head injury, trauma, thrombosis, urolithiasis, after thoracic interventions, fracture follow-up and cancer staging/follow-up were the most frequently identified low-value imaging examinations. The proportion of low-value imaging varied between 2 and 100% inappropriate or unnecessary examinations.

CONCLUSIONS

A comprehensive list of identified low-value radiological examinations for both adults and children are presented. Future research should focus on reasons for low-value imaging utilization and interventions to reduce the use of low-value imaging internationally.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42020208072.

Failure of anterior skull base reconstruction for sinonasal carcinoma: consequence on the postoperative follow up. A multicentre evaluation of management

BACKGROUND

Numerous techniques for closure of the anterior skull base in cancer patients have a high success rate but management of failure is poorly documented.

OBJECTIVES

To standardize the post-operative follow-up after reconstruction surgery of the anterior skull base after removal for sinonasal carcinoma.

MATERIALS AND METHODS

Retrospective review of failure of anterior skull base reconstruction between 2005 and 2018 in a multicenter setting.

RESULTS

Twenty four patients were included. Reconstruction failure was detected by a cerebrospinal (CSF) leak in 79.2%, by an infectious complication without CSF leak (i.e. meningitis) in 12.5%, and in 8.3% by extensive pneumocephalus. Failure was observed during the first week after surgery in 75% of patients, in the second week in 21%, and in 4% after day 15. The delay in discovery of the failure was associated with multilayer reconstruction (p=.03). Failure was treated surgically in 54% of the patients and medically in 46%, with a similar success rate (85 vs. 100%).

CONCLUSION AND SIGNIFICANCE

After carcinologic resection of the anterior skull base, monitoring should be systematic during the first postoperative week. Surgical management of failure is not always necessary.

Routine postoperative computed tomography scan after craniotomy: systematic review and evidence-based recommendations

Over the last few years, the role of early postoperative computed tomography (EPOCT) after cranial surgery has been repeatedly questioned, but there is yet no consensus on the practice. We conducted a systematic review to address the usefulness of EPOCT in association with neurological examination after elective craniotomies compared to the neurological examination alone. Studies were eligible if they provided information about the number of patients scanned, how many were asymptomatic or presented neurological deterioration before the scan and how many of each of those groups had their management changed due to imaging findings. CTs had to be performed in the first 48 h following surgery to be considered early. Eight studies were included. The retrospective studies enrolled a total of 3639 patients, with 3737 imaging examinations. Out of the 3696 CT scans performed in asymptomatic patients, less than 0.8% prompted an intervention, while 100% of patients with neurological deterioration were submitted to emergency surgery. Positive predictive values of altered scans were 0.584 for symptomatic patients and 0.125 for the asymptomatic. The number of altered scans necessary to predict (NNP) one change in management for the asymptomatic patients was 8, while for the clinically evident cases, it was 1.71. The number of scans needed to diagnose one clinically silent alteration is 134.75, and postoperative imaging of neurologically intact patients is 132 times less likely to issue an emergency intervention than an altered neurological examination alone. EPOCT following elective craniotomy in neurologically preserved patients is not supported by current evidence, and CT scanning should be performed only in particular conditions. The authors have developed an algorithm to help the judgment of each patient by the surgeon in a resource-limited context.

Efficacy of routine post-operative head computed tomography on cranial surgery patients outcome

Objectives:

To identify the role of routine postoperative head CT in changing postoperative management after elective craniotomies.

Methods:

We conducted a retrospective study on adult patients who underwent cranial surgery. Exclusion criteria includes cranial CTs done postoperatively for urgent clinical indications, pediatric patients, CSF diversion procedures and sedated patients. Patients were placed into “positive” group if the physical assessment changed from the baseline in the form of clinical deterioration, and the “negative” group if the exam did not change. The data then were analyzed to identify which patients needed further medical or surgical management based on CT findings only with “negative” physical examination.

Results:

Total of 222 were included in the study. 151 patients had negative physical examination. Only 8 out of 151 patients had positive CT findings. Two patients out of 222 (0.9%) had a negative physical exam and positive CT findings that required additional action that wouldn’t be done urgently without routine postoperative brain CT. Only one patient out of 222 (0.4%) who was re-operated urgently based CT findings only and negative physical examination.

Conclusion:

Routine postoperative routine brain CT did not alter the course of medical management, even in the presence of significant radiological findings.

Straws Don't Suck: Are Straws Dangerous after Endoscopic Skull Base Surgery?

Objective Patients undergoing endoscopic endonasal surgery have historically been restricted from using straws postoperatively, due to the concern that this activity generates negative pressure. The objective of this study is to evaluate the pressure dynamics in the sinonasal cavity associated with the use of a straw.

Methods Intracranial pressure catheters were placed in the nasal cavity of 20 healthy individuals. Pressure measurements were then recorded while participants drank liquids of different viscosities from a cup and from a straw. Measurements were recorded with and without subjects occluding their nose to simulate postoperative nasal obstruction.

Results The average pressure in the nasal cavity while drinking water from a cup was −0.86 cmH2O, from a straw was −1.09 cmH2O, and while occluding the nose and using a straw was −0.81 cmH2O. The average pressure in the nasal cavity while drinking a milkshake from a cup was −0.98 cmH2O, from a straw was −1.88 cmH2O, and while occluding the nose and using a straw was −1.37 cmH2O. There was no statistically significant difference in pressure measurements when comparing either task or consistency (p > 0.05).

Conclusion Straw use is not associated with the generation of significant negative pressure in the nasal cavity. The pressure generated when drinking from a straw is not significantly different from that of drinking from a cup. This data suggest that straw use may be safe for patients following endoscopic skull base surgery, but further investigation is warranted.

The expanded endonasal approach in pediatric skull base surgery: A review

OBJECTIVE

Surgery of the pediatric skull base has multiple unique challenges and has seen recent rapid advances. The objective of this review is to assess key issues in pediatric skull base surgery (SBS), including anatomic limitations, surgical approaches, reconstruction techniques, postoperative care, complications, and outcomes.

DATA SOURCES

PubMed literature review.

REVIEW METHODS

A review of the literature was conducted to assess the challenges, recent advances, and reported outcomes in pediatric SBS.

RESULTS

The pediatric skull base presents multiple anatomic challenges, including variable patterns of pneumatization, narrow piriform aperture width, and narrow intercarotid distance at the level of the cavernous sinus but not the superior clivus. These issues may be particularly challenging in patients less than 2 years of age. Endoscopic endonasal approaches in the sagittal and coronal plane have been applied to the pediatric skull base while open approaches may still be necessary in the setting of extensive intracranial or orbital disease, as well as disease lateral to critical neurovascular structures. While the nasoseptal flap was initially called into question for pediatric cases, it has been shown through multiple reports to be a feasible and robust reconstructive option. Complications and outcomes often depend upon the pathology. In children, response to noxious stimuli, ability to avoid Valsalva, and adherence to nasal precautions is variable. The use of lumbar drains is more common in pediatric than adult patients.

CONCLUSION

While the pediatric skull base presents unique challenges, outcomes data support that endoscopic endonasal approaches are a pertinent surgical technique in appropriately selected patients.

LEVEL OF EVIDENCE

3a.

International practice variation in postoperative imaging of chronic subdural hematoma patients

OBJECTIVE

The value of CT scanning after burr hole surgery in chronic subdural hematoma (CSDH) patients is unclear, and practice differs between countries. At the Brigham and Women's Hospital (BWH) in Boston, Massachusetts, neurosurgeons frequently order routine postoperative CT scans, while the University Medical Center Utrecht (UMCU) in the Netherlands does not have this policy. The aim of this study was to compare the use of postoperative CT scans in CSDH patients between these hospitals and to evaluate whether there are differences in clinical outcomes.

METHODS

The authors collected data from both centers for 391 age- and sex-matched CSDH patients treated with burr hole surgery between January 1, 2002, and July 1, 2016, and compared the number of postoperative scans up to 6 weeks after surgery, the need for re-intervention, and postoperative neurological condition.

RESULTS

BWH patients were postoperatively scanned a median of 4 times (interquartile range [IQR] 2-5), whereas UMCU patients underwent a median of 0 scans (IQR 0-1, p < 0.001). There was no significant difference in the number of re-operations (20 in the BWH vs 27 in the UMCU, p = 0.34). All re-interventions were preceded by clinical decline and no recurrences were detected on scans performed on asymptomatic patients. Patients' neurological condition was not worse in the UMCU than in the BWH (p = 0.43).

CONCLUSIONS

While BWH patients underwent more scans than UMCU patients, there were no differences in clinical outcomes. The results of this study suggest that there is little benefit to routine scanning in asymptomatic patients who have undergone surgical treatment of uncomplicated CSDH and highlight opportunities to make practice more efficient.

Utility of early postoperative imaging after combined endoscopic and open ventral skull base surgery

PURPOSE

Immediate postoperative imaging is frequently obtained after combined skull base surgery (SBS) with endoscopic endonasal and open transcranial approaches. The importance of early postoperative imaging for detecting complications in these patients is still debatable. In this study, we investigated the clinical utility of early postoperative imaging after combined SBS for determination of postoperative complications.

METHODS

A retrospective chart analysis of 21 cases of combined SBS between 2009 and 2015 was performed. Data on postoperative computed tomography (CT) and magnetic resonance imaging (MRI), and the hospital course were collected. We separated interpretations of postoperative imaging into two groups: (1) when using the radiologist's interpretation alone, and (2) when using the surgeon's knowledge of the case in conjunction with imaging.

RESULTS

Forty-two postoperative scans were obtained (21 CT, 21 MRI) within 48 hours of surgery. There was a significant statistical difference between imaging interpretation by surgeons and radiologists for CT interpretation only. For CT interpretation the true positive (TP), false positive (FP), true negative (TN), and false negative (FN) rates for radiologists (TP, 0/21; FP, 6/21; TN, 11/21; FN, 4/21) slightly deviated from surgeons' interpretation (TP, 1/21 [p = 0.9999]; FP, 0/21 [p = 0.0207]; TN, 17/21 [p = 0.1000]; FN, 3/21 [p = 1.000]). Rates for MRI interpretation by both groups were nearly identical, with no significant difference found. Overall, four patients experienced seven postoperative complications, which led to a complication rate of 19.0% (4/21). The patients exhibited clinical symptoms in all instances of postoperative complications that required further intervention.

CONCLUSION

The benefit of early postoperative imaging to detect complications after combined SBS was limited. In this cohort of patients, positive imaging findings' effects on patient management were dictated by the presence of supporting clinical symptoms.

Management of Skull Base Defects After Surgical Resection of Sinonasal and Ventral Skull Base Malignancies

Over the past 2 decades, there has been a significant increase in the resection of larger and more complex ventral skull base malignancies. The resection of these lesions has resulted in the creation of larger and more difficult to repair skull base defects. There are many available options for ventral skull base reconstruction. Despite the variety of reconstructive options, the key objective is to eliminate any communication between the intracranial space and the sinonasal cavity. This article discusses some of the more common techniques currently used for repair of these skull base defects.

Comprehensive Postoperative Management After Endoscopic Skull Base Surgery

To maximize outcomes from endoscopic skull base surgery, careful early postoperative management is critically important. Standardized postoperative regimens are lacking. The type of reconstruction and presence and type of cerebrospinal fluid leak dictate management. If a leak is encountered intraoperatively, patients should avoid maneuvers that increase intracranial pressures for at least 1 month. Early postoperative care focuses on minimizing and managing nasal crusting. This article reviews the evidence in the literature on postoperative management, complications, and quality of life after surgery, and outlines our experience in the management of patients after endoscopic skull base surgery.

Neurologic Complications and Treatment

Risk is inherent with all surgical procedures. Most endoscopic sinus surgery (ESS) is uncomplicated. Among the many complications inherent with ESS are the neurologic complications, which include cerebrospinal fluid rhinorrhea, traumatic soft tissue and vascular injuries, infection, and seizures. Despite intense review of a patient's preoperative scans, use of stereotactic image guidance, and an expert understanding of anatomy, neurologic complications occur. An understanding of these complications and how to manage them can help to reduce long-term patient injury as well as help prevent recurrence.