Risk factors for cerebrospinal leak after endoscopic skull base reconstruction with nasoseptal flap.

The use of expanded endonasal surgery (EES) in the treatment of skull base neoplasms has increased significantly in recent years. Since 2006, the nasoseptal flap (NSF) has become the workhorse for the closure of skull base defects involving the anterior and central skull base. We hypothesized that defect site impacts the rate of cerebrospinal fluid (CSF) leak following EES. Retrospective cohort study. Patients who underwent skull base defect repair using a NSF at the University of California at San Francisco (UCSF) minimally invasive skull base center were retrospectively reviewed. Patient demographics, disease, and defect location and size were recorded along with the presence of a postoperative CSF leak. Data were analyzed using Fisher's exact test. One hundred and twenty-one patients met inclusion criteria. Ten patients had a NSF failure with CSF leakage, 2 in the anterior skull base (frontal sinus, ethmoid, cribriform, planum), and 8 in the central skull base (sella, clivus) (P = .047). Dural defect size ≥2.0 cm(2) in the central skull base strongly correlated with the risk of flap failure (P = .034). This study of endoscopic closure of skull base defects using a NSF demonstrates there is an association between both surgical site and dural defect size with NSF failure. Expanded defects of the sella and clivus have an increased risk of failure and may warrant augmented techniques.

Gruss CL ，Al Komser M ，Aghi MK ，Pletcher SD ，Goldberg AN ，McDermott M ，El-Sayed IH ... -  《-》

Radiographic enhancement of the nasoseptal flap does not predict postoperative cerebrospinal fluid leaks in endoscopic skull base reconstruction.

Cerebrospinal fluid (CSF) leaks continue to be the most common postoperative complication in expanded endonasal skull base procedures. Currently, a multilayer closure using a vascularized nasoseptal flap is most commonly performed for large ventral skull base defects in an effort to avoid postoperative CSF leaks. We correlated nasoseptal flap enhancement with postoperative CSF leak rates in a group of skull base reconstruction patients. The nasoseptal flap enhancement was determined by immediate postoperative gadolinium-enhanced magnetic resonance imaging (MRI), which allowed for imaging of the flap's vascular pedicle. Our aim was to identify whether nasoseptal flap enhancement contributed to reduction of postoperative CSF leak rates. Retrospective cohort study. We reviewed 19 patients who underwent expanded endoscopic resections of skull base lesions of advanced complexity. We calculated the incidence of CSF leaks and measured the presence of nasoseptal flap enhancement. Of the 19 patients with immediate postoperative MRIs, three developed postoperative CSF leaks. All three CSF leaks were in cases with enhancing vascular pedicles. In contrast, we had three patients without evidence of flap enhancement, none of whom developed a postoperative CSF leak (Fisher exact test, P = 1.0). CSF leak was associated with posterior fossa lesions (P = .25). Nasoseptal flap enhancement was associated with younger age (P = .15). This retrospective cohort study demonstrates that although the vascularized pedicled nasoseptal flap is effective for closure of expanded endonasal skull base procedures, our experience found the actual enhancement of the flap itself does not appear to effect postoperative CSF leak rates.

Adappa ND ，Learned KO ，Palmer JN ，Newman JG ，Lee JY ... -  《-》

Nasoseptal flap repair after endoscopic transsellar versus expanded endonasal approaches: is there an increased risk of postoperative cerebrospinal fluid leak?

The development of expanded endoscopic endonasal approaches (EEAs) has allowed resection of cranial-base lesions beyond the sella. One major criticism is an increased risk of postoperative cerebrospinal fluid (CSF) leakage because of the larger skull base defect. We evaluated our experience with vascularized pedicled nasoseptal flap (PNSF) reconstruction and compared the postoperative CSF leak rates between patients undergoing endoscopic transsphenoidal (transsellar) approaches versus expanded EEA (transplanum-transtuberculum, transcribriform, transclival). Retrospective analysis at a tertiary care medical center. A retrospective review of a prospective database was performed on patients who underwent PNSF reconstruction for intraoperative high-flow CSF leaks after EEA between December 2008 and August 2011. Demographic data, repair materials, surgical approach, and incidence of postoperative CSF leaks were collected. Thirty-seven transsellar defects (group I) were repaired with a PNSF, and 32 expanded EEA defects (19 transplanum-transtuberculum, 10 transcribriform, three transclival) (group II) were repaired with a PNSF. No postoperative CSF leaks occurred in group I. One delayed postoperative CSF leak was encountered in group II leading to a 3.1% leak rate in that group. The incidence of postoperative CSF leakage was not significantly different between the two groups (P > .05). Our overall success rate in this series using a PNSF was 98.6%. Based on our data, there is no significant increased risk of postoperative CSF leak between transsellar and expanded EEA defects when a PNSF is used. The potential risk of postoperative CSF leaks associated with larger defects created through expanded EEA can be minimized by multilayered closure with a PNSF and meticulous surgical technique.

Eloy JA ，Choudhry OJ ，Shukla PA ，Kuperan AB ，Friedel ME ，Liu JK ... -  《-》

Long-term effectiveness of a reconstructive protocol using the nasoseptal flap after endoscopic skull base surgery.

To describe the effect on postoperative cerebrospinal fluid (CSF) leak after anterior skull base (ASB) surgery and complications associated with the addition of the vascularized nasoseptal flap (NSF) to an existing reconstruction protocol. A prospective database of all patients undergoing endoscopic ASB approaches was reviewed. Patients were divided into three groups based on the date the use of the NSF was adopted. Group A included patients with high-volume CSF leak closed using the NSF in addition to a multilayer closure. Group B included patients operated on during the same time period with no high-volume leak and no NSF. Group C included patients operated on before the adoption of the NSF with all types of CSF leak. Rates of intraoperative and postoperative CSF leak were analyzed for statistical significance. Of 415 consecutive patients undergoing endoscopic ASB surgery, there were 96 in group A, 114 in group B, and 205 in group C. CSF leak rates in group A (3.1%) and group B (2.6%) were significantly lower than in group C (5.9%; P < 0.05). Lumbar drains and the gasket seal closure were performed more frequently in group A (75% and 32%) compared with group B (21% and 12%) and group C (28% and 11%). NSF carried a 2% risk of postoperative mucocele. The addition of NSF to an algorithm for multilayer closure can decrease the rate of postoperative CSF leak.

McCoul ED ，Anand VK ，Singh A ，Nyquist GG ，Schaberg MR ，Schwartz TH ... -  《-》

Endoscopic Endonasal Reconstruction of Intraoperative Cerebrospinal Fluid Leak in Different Skull Base Regions: Outcomes, Meningitis, and Risk Factors.

Various nonvascularized or vascularized techniques have been adopted in endoscopic endonasal surgery (EES) for repairing intraoperative cerebrospinal fluid (CSF) leaks after tumor resection. Vascularized nasoseptal flaps, free nasoseptal grafts, free turbinate grafts, and fascia lata and mashed muscle are frequently used. Outcomes of those grafts applied in the defects of different regions need to be clarified. The data from a series of 162 patients with skull base tumor who underwent EES that had intraoperative CSF leak between Jan 2012 and Jan 2021 were retrospectively analyzed. The regions included anterior skull base, sellar region, clivus and infratemporal fossa. Repair failure rate (RFR), meningitis rate, and associated risk factors were assessed. In total, 172 reconstructions were performed in 162 patients for the 4 sites of the skull base. There were 7 cases (4.3%) that had postoperative CSF leaks, which required second repair. The RFR for anterior skull base, sellar region, clivus, and infratemporal fossawas 2.6%, 2.2%, 16.7%, and 0%, respectively. The clivus defect was an independent risk factor for repair failure (P < 0.01). The postoperative meningitis rate was 5.6%. Repair failure was an independent risk factor for meningitis (P < 0.01). Vascularized nasoseptal flap, free nasoseptal graft, free turbinate graft, and fascia lata and mashed muscle are reliable autologous materials for repairing the dural defects in different regions during EES. Clivus reconstruction remains a great challenge, which had a higher RFR and meningitis rate. Repair failure is significantly associated with postoperative meningitis.

Wei W ，Yan B ，Zhang Q ，Qi Y ，Ren Q ，Wang L ，Liu J ，Yang X ，Wang Z ... -  《-》