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 ... -  《-》

Efficacy of the pedicled nasoseptal flap without cerebrospinal fluid (CSF) diversion for repair of skull base defects: incidence of postoperative CSF leaks.

The advances in endoscopic skull base surgery have led to the resection of increasingly larger cranial base lesions and the creation of larger skull base defects with the potential for increased postoperative high-flow cerebrospinal fluid (CSF) leaks. These concerns led to the development of the vascularized pedicled nasoseptal flap (PNSF), which is now used as the mainstay for repair of large skull base defects in many academic centers. In this report, we review the incidence of postoperative CSF leaks in our institution in patients undergoing endoscopic skull base repair of high-flow CSF leaks with a vascularized PNSF without concurrent CSF diversion. We performed a retrospective analysis at our tertiary care medical center on patients who underwent endoscopic repair of high-flow CSF leaks using a PNSF without CSF diversion between July 2008 and August 2011. Repair materials, incidence of postoperative CSF leaks, and demographic data were collected. Fifty-nine high-flow CSF leaks were repaired with a PNSF and other repair materials, without the use of lumbar catheter drainage. No postoperative CSF leak occurred in this cohort of patients. The overall postoperative CSF leak rate was 0%. Meticulous multilayer-closure of skull base defects is critical to prevent postoperative CSF leaks. Although lumbar drainage may be useful in select scenarios, it carries inherent risks of intracranial hypotension and pneumocephalus, and may not be necessary for routine management of high-flow CSF leaks in conjunction with a robust PNSF. Further prospective randomized controlled studies may be warranted to evaluate the efficacy of postoperative lumbar drainage.

Eloy JA ，Kuperan AB ，Choudhry OJ ，Harirchian S ，Liu JK ... -  《-》

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 ... -  《-》

Various modifications of a vascularized nasoseptal flap for repair of extensive skull base dural defects.

Moon JH ，Kim EH ，Kim SH 《-》