Icing and multilayering technique of injectable hydroxyapatite cement paste for cranial base reconstruction after transsphenoidal surgery: technical note

Efficacy of hydroxyapatite-based skull base reconstruction for intraoperative high-flow cerebrospinal fluid leakage performed by less-experienced surgeons

Cerebrospinal fluid (CSF) leakage after endoscopic skull base surgery remains a challenge despite multilayer reconstruction including nasoseptal flap (NSF) has become a standard technique. Injectable hydroxyapatite (HXA) has shown promising results to prevent CSF leakage. This study aimed to validate the efficacy of HXA-based skull base reconstruction performed by less-experienced neurosurgeons who had short-term clinical experiences as independent surgeons. Between March 2018 and November 2022, 41 patients who experienced intraoperative high-flow CSF leakage following endoscopic endonasal surgery at two independent tertiary institutions were enrolled. Skull base reconstruction was performed using conventional multilayer techniques combined with or without HXA. The primary outcome was postoperative CSF leakage. The surgical steps and nuances were described in detail. The most common pathology was craniopharyngioma. Injectable HXA was used in 22 patients (HXA group) and conventional techniques were performed in 19 patients (control group). The HXA group achieved a significantly lower incidence of postoperative CSF leakage than the control group (0% vs. 26.3%, p = 0.016). No HXA-related complications were observed. The use of injectable HXA in skull base reconstruction was highly effective and safe. This technique and its favorable results might be readily reproduced by less-experienced neurosurgeons.

Clinical Impact of Hydroxyapatite on the Outcome of Skull Base Reconstruction for Intraoperative High-Flow CSF Leak: A Propensity Score Matching Analysis

Background

Despite recent advances in skull base reconstructive techniques, including the multilayer technique during the last decade, complete reconstruction of grade 3 intraoperative high-flow cerebrospinal fluid (CSF) leak remains challenging. This study was designed to investigate the role of injectable hydroxyapatite (HXA) used in the multilayer technique on the clinical outcome of skull base reconstruction for intraoperative high-flow CSF leak.

Materials and Methods

This study enrolled 187 patients who experienced intraoperative high-flow CSF leak after endoscopic endonasal surgery for anterior skull base or suprasellar pathologies between January 2014 and July 2021. All skull base defects were reconstructed using the conventional multilayer technique including a vascularized naso-septal flap (NSF, n = 141) and the combined use of HXA with the conventional multilayer technique (HXA group, n = 46). We retrospectively evaluated the efficacy of the HXA group by 1:2 propensity score matching analysis.

Results

Overall, 17 of 187 patients (9.1%) showed postoperative CSF leaks, resulting in second reconstruction surgery. There were no statistical differences in patient age, sex, body mass index, tumor location, tumor type, and degree of resection, except for the follow-up period between the two groups. The HXA group showed a significantly lower incidence of postoperative CSF leak than the control group (0% vs. 12.1%, p < 0.05). Postoperative lumbar drain (LD) was performed in 8.7% of the HXA group compared to 46.1% of the control group (p < 0.01). CSF leak-related infection rates showed a decreasing tendency in the HXA group compared to the control group (0 vs. 7.1%, p = 0.06). A total of 46 patients in the HXA group were well matched with the control group (92 patients) at a 1:2 ratio. In the propensity score-matched control group, there were higher rates of postoperative CSF leaks than in the HXA group.

Conclusion

The use of HXA combined with the conventional multilayer technique completely reduced postoperative CSF leaks in this study. This technique resulted in reduced CSF leakage, even without postoperative LD, and decreased infection rates. Further randomized comparative studies are required to confirm our findings.

Outcomes of the endoscopic endonasal approach for tumors in the third ventricle or invading the third ventricle

We aimed to retrospectively analyze the surgical and clinical outcomes of the endoscopic endonasal approach (EEA) for tumors in the third ventricle or invading the third ventricle. In total, 82 patients who had undergone surgical treatment using the EEA for tumors involving the third ventricle were enrolled in this study. This cohort study comprised 46 male and 36 female patients. The median age was 37 years (range, 5-76), and the median follow-up duration was 56.5 months (range, 6-117). Seventy-six patients had craniopharyngiomas, and 6 had gangliocytomas, gangliogliomas, astrocytomas, diffuse midline gliomas and lymphomas. Gross total removal was performed in 71 (86.5%) of the 82 patients, subtotal tumor removal in 7 patients and partial removal or biopsy in 4 patients. The pituitary stalk was preserved in 20 cases. Visual function improved in 40 (81.6%) of 49 patients. Endocrine function worsened in 41 (50%) of 82 patients. Hypothalamic function improved in 16 (72.7%) of 22 cases. Postoperative obesity occurred in 3 (20.0%) of 15 children and 11 (23.9%) of 46 adult patients. The postoperative cerebrospinal fluid leakage rate was 3.6%. Postoperative meningitis occurred in 18 (21.9%) cases. Permanent diabetes insipidus was identified in 73 (89.0%) of 82 patients. Tumor recurrence was observed in 10 patients (12%). The EEA appears to be a safe and effective treatment modality for tumors in the third ventricle or involving the third ventricle. However, more cases and long-term follow-up outcomes are required to confirm the clinical efficacy of the EEA.

Multi-Layer Onlay Graft Using Hydroxyapatite Cement Placement without Cerebrospinal Fluid Diversion for Endoscopic Skull Base Reconstruction

Objective

The skull base reconstruction step, which prevents cerebrospinal fluid (CSF) leakage, is one of the most challenging steps in endoscopic skull base surgery (ESS). The purpose of this study was to assess the outcomes and complications of a reconstruction technique for immediate CSF leakage repair using multiple onlay grafts following ESS.

Methods

A total of 230 consecutive patients who underwent skull base reconstruction using multiple onlay grafts with fibrin sealant patch (FSP), hydroxyapatite cement (HAC), and pedicled nasoseptal flap (PNF) for high-flow CSF leakage following ESS at three institutions were enrolled. We retrospectively reviewed the medical and radiological records to analyze the preoperative features and postoperative results.

Results

The diagnoses included craniopharyngioma (46.8%), meningioma (34.0%), pituitary adenoma (5.3%), chordoma (1.6%), Rathke’s cleft cyst (1.1%) and others (n=21, 11.2%). The trans-planum/tuberculum approach (94.3%) was the most commonly adapted surgical method, followed by the trans-sellar and transclival approaches. The third ventricle was opened in 78 patients (41.5%). Lumbar CSF drainage was not performed postoperatively in any of the patients. Postoperative CSF leakage occurred in four patients (1.7%) due to technical mistakes and were repaired with the same technique. However, postoperative meningitis occurred in 13.5% (n=31) of the patients, but no microorganisms were identified. The median latency to the diagnosis of meningitis was 8 days (range, 2–38). CSF leakage was the unique risk factor for postoperative meningitis (p<0.001).

Conclusion

The use of multiple onlay grafts with FSP, HAC, and PNF is a reliable reconstruction technique that provides immediate and complete CSF leakage repair and mucosal grafting on the skull base without the need to harvest autologous tissue or perform postoperative CSF diversion. However, postoperative meningitis should be monitored carefully.

3D T2-weighted turbo spin-echo MR sequence for identifying cerebrospinal fluid leak after endoscopic endonasal pituitary surgery

BACKGROUND

This study aimed to assess the efficacy of MR images with 3D T2-weighted turbo spin-echo (3D T2-TSE) sequences for early identification of postoperative cerebrospinal fluid (CSF) leaks.

METHODS

We analyzed the medical records and radiological reports for 72 consecutive patients who underwent an endoscopic endonasal approach for sellar and parasellar lesions between April 2009 and December 2010. Patients were 38 men and 34 women with a mean age of 46.4 years. All underwent MR scanning within 2 postoperative days, which included 3D T2-TSE sequences as well as a conventional T2-weighted (T2W) protocol. Sequence accuracy in predicting postoperative CSF leaks was assessed for sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV).

RESULTS

A postoperative CSF leak was confirmed in 6 of 72 patients (8.3 %). On immediate postoperative MR images, 39 patients were suspicious for CSF leaks on conventional T2W sequences, while 18 patients on 3D T2-TSE. The 3D T2-TSE imaging had superior specificity and PPV (50 % vs. 81.8 %, 15.4 % vs. 33.3 %), while there was no difference in sensitivity and NPV compared with conventional T2W sequences.

CONCLUSION

Compared to the conventional T2W protocol, MR imaging with the 3D T2-TSE protocol provides differential images around the sellar area with improved specificity and PPV for the detection of postoperative CSF leaks.

Injectable hydroxyapatite cement patch as an on-lay graft for the sellar reconstructions following endoscopic endonasal approach

BACKGROUND

Skull base reconstruction after endoscopic endonasal resection of a variety of skull base lesions remains challenging because of some lethal complications such as cerebrospinal fluid (CSF) leaks. We investigated the outcomes of hydroxyapatite (HA) cement patch as on-lay graft for skull base defects following endoscopic endonasal approach (EEA).

METHODS

We analyzed 53 consecutive patients who underwent sellar reconstruction using HA cement following EEA at our institution between July 2009 and March 2011. Patients were composed of 23 men and 30 women with a mean age of 47 years, ranging from 10 to 72 years. Among these patients, 29 patients (54.7%) experienced intraoperative CSF leaks with high-output, 10 patients (18.9%) underwent CSF leaks with low output, and 14 patients (26.4%) experienced no intraoperative CSF leak. Mean follow-up period for clinical outcomes was 8.6 months (range, 3-22 months).

RESULTS

We performed injectable HA patch as on-lay graft over fascia lata for the skull base defects. Routine lumbar CSF drainage was not performed postoperatively in any patients since the introduction of HA. During the follow-up period, three of 53 patients (5.6%) demonstrated meningitis associated with postoperative CSF leaks and underwent re-do reconstruction surgery. There was no allergic symptoms associated with HA cement. At an outpatient clinic, the defects were found to be covered with surrounding nasal mucosa at an average of 14 weeks (range, 3-28 weeks).

CONCLUSIONS

The use of HA cement as an on-lay patch for the reconstruction of sellar defect demonstrated a low incidence of CSF leaks with minimal complications. HA cement may be an alternative option for repair of CSF leaks following EEA.

Polyethylene glycol (PEG) hydrogel dural sealant and collagen dural graft matrix in transsphenoidal pituitary surgery for prevention of postoperative cerebrospinal fluid leaks

Cerebrospinal fluid (CSF) rhinorrhea is the most common complication after transsphenoidal pituitary surgery. The authors compare their previous experience using an autologous fat graft and lumbar drain placement in 107 patients with their current technique of using a dural sealant and collagen matrix in 97 patients to prevent postoperative CSF leak after pituitary tumor resection. The failure rate for CSF leak repairs between the two groups was similar. The use of a dural sealant and collagen matrix, however, has the advantages of decreased length of hospital stay, decreased length of Intensive Care Unit stay, avoidance of the morbidity of an extra abdominal incision, and avoidance of the risks of lumbar CSF drainage.