Hadad-Bassagasteguy flap
The Hadad-Bassagasteguy vascularized nasoseptal pedicled flap (HBF) is an effective technique for the reconstruction of skull base defects with a low incidence of postoperative cerebrospinal fluid leak. Advanced planning is required as posterior septectomy during transsphenoidal surgery can preclude its use due to the destruction of the vascular pedicle.
Endonasal Approaches (EEAs) have been widely used for various skull base lesions. The reconstruction of the skull base defects is of vital importance to prevent postoperative complications. The vascular pedicled-nasoseptal flap (Hadad-Bassagasteguy flap) is used as a workhorse in reconstruction of majority of the defects.
MRI is a very useful tool in assessing the viability of the flap postoperatively and to evaluate for variations that may suggest potential flap failure 1).
see Hadad Bassagasteguy vascularized nasoseptal pedicled flap.
Releasing the nasoseptal flap (NSF) pedicle from the sphenopalatine foramen may considerably improve flap reach and surface area.
The objectives of Shastri et al., were quantify increases in pedicle length and NSF reach through extended pedicle dissection into the pterygopalatine fossa (PPF) through cadaveric dissections and present clinical applications.
Twelve cadaveric dissections were performed. Following standard NSF harvest, the distance from the anterior edge of the flap to the anterior nasal spine while pulling the flap anteriorly was measured. As dissection into the SPA foramen and PPF continued, similar interval measurements were completed in four stages after release from the SPA foramen, release of the internal maxillary artery (IMAX), and transection of the descending palatine artery (DPA). The extended pedicle dissection technique was performed in seven consecutive patients for a variety of different pathologies.
The mean length of the NSF from the anterior nasal spine and maximum flap reach were 1.91 ± 0.40 cm/9.3 ± 0.39 cm following standard harvest, 2.52 ± 0.61 cm/9.75±1.06 cm following SPA foramen release, 4.93 ± 0.89 cm/12.16 ± 0.54 cm following full IMAX dissection, and 6.18 ± 0.68 cm/13.41 ± 0.75 cm following DPA transection. No flap dehiscence or necrosis was observed in all seven surgical patients.
Extended pedicle dissection of the NSF to the SPA/IMAX markedly improves the potential length and reach of the flap. This technique may provide a feasible option for reconstruction of large anterior skull base and craniocervical junction defects. Seven successful cases are presented here, but further studies with larger series are warranted to validate findings in a clinical setting 2).
Nasoseptal flap reconstruction is a widely accepted method for reducing cerebrospinal fluid (CSF) leakage following endoscopic transnasal surgeries (ETSs). However, this method is associated with nasal complications and has difficulty in repeatedly applying for recurrent cases. Therefore, alternative methods are needed.
METHODS: Layers of autologous fascia lata were placed on the inside and outside of the dural defect to sufficiently cover it, and the grafts were compressed with an inflated balloon. A lumbar drainage system with a pressure-control valve was used for 72 hours postoperatively. We retrospectively analyzed data on patients with skull base lesions showing intracranial extensions that required wide opening of the ventral dura in ETS. Fifty cases (47 skull base tumors and 3 others) were included, in which 28 were recurrent cases.
RESULTS: In 21 cases (42%), the nasal septum was not intact because of the previous ETS. Seventeen patients (34%) had a history of radiotherapy and 9 (18%) had undergone multi-session radiotherapies. None of the 50 patients required additional surgery for postoperative CSF rhinorrhea, while 2 had intermittent CSF leakage that resolved with prolonged lumbar drainage placement for a week. Prior multi-session radiotherapy was the only significant risk factor for the need of prolonged drainage (p = 0.029).
The multi-layer closure method with pressure control spinal drainage system is a simple, safe, and effective method for preventing postoperative CSF leakage, which can be readily applied for the dural defects in any parts of the skull base regions and for patients with various conditions 3).
The management of patients with diabetes mellitus, cardiovascular problems, advanced age, postoperative nasal infection, and radiation therapy may require more attention to improve NSF survival 4).
A retrospective radioanatomic analysis was conducted in 100 Korean adult patients. Septal and skull-base dimensions were measured and the feasibility of the NSF in reconstructing a full anterior skull-base defect was evaluated. Scans of 49 white patients were analyzed for a comparative study.
Among various septal dimensions, the length of the septum was significantly different in Koreans when compared to whites. Skull-base dimensions such as anterior skull-base length and width at the level of the anterior ethmoidal artery were different between the 2 ethnic groups. Individual differences between the anterior width of the hypothetical NSF and the anterior margin of the skull-base defect (2.8 ± 3.1 vs 6.4 ± 4.8) and the difference between the hypothetical NSF length and the length of the flap needed for full coverage of the defect were significantly smaller in Korean patients (7.2 ± 3.8 vs 13.1 ± 5.6), leading to a statistically higher chance of flap insufficiency. The insufficiency was more often found in female patients.
The risk of NSF insufficiency for covering the anterior skull-base defect in Koreans is higher relative to whites, and is accentuated in female patients. Efforts to increase the size of the NSF as well as efforts to avoid intraoperative shrinkage of the NSF should be considered to compensate for the relatively small NSF in Asians 5).
Case series
2017
A prospective study of 13 patients was done, who underwent endoscopic skull base surgery with reconstruction using the Hadad-Bassagasteguy flap. Pre-operative MRI was done to assess the size, extent and location of the lesion and a postoperative MRI was done to evaluate flap configuration, enhancement patterns, location, flap thickness and signal intensity characteristics.
The postoperative MRI of all patients showed a detectable flap covering over the skull base defects forming an “open cup” appearance. They were uniformly isointense on T1-weighted/ fat suppressed images to the adjacent nasal mucosa and hyperintense on T2-weighted images. On the MRI scans done after four weeks, all 13 of our patients had enhancing flaps. One flap migrated slightly to the left side; however, there was no Cerebrospinal Fluid (CSF) leak.
Vascular pedicle nasoseptal (Hadad) flaps are being widely used. MRI is a very useful tool in assessing the viability of the flap postoperatively and to evaluate for variations that may suggest potential flap failure 6).
2014
In four cases in which the HBF was successfully used to repair recurrent CSF leaks despite prior posterior septectomy and transsphenoidal surgery.
Two were men and two were women with a mean age of 37 years (range, 24-48 years). All had previously undergone resection of a pituitary macroadenoma via a transsphenoidal approach, with intraoperative CSF leaks repaired using multilayered free grafts. Recurrent CSF rhinorrhea arose 0.37-12 months (mean, 2.98 months) after the initial pituitary surgery. Active CSF drainage could be visualized intraoperatively with posterior septal perforations present. The HBF was successfully used in all cases, with no evidence of recurrent CSF leak after a mean follow-up of 2.35 years. The HBF may be salvaged for repair of recurrent CSF leaks even in the context of prior posterior septectomy and transsphenoidal surgery. However, longer follow-up is necessary to determine the long-term efficacy of this procedure in such revision cases 7).