Head & Neck Institute Outcomes
Rhinology, Sinus and Skull Base Disorders
Simplifying the Transpterygoid Approach to Lateral Sphenoid Meningoencephaloceles: A Shorter Run for a Longer Slide
Cerebrospinal fluid (CSF) leaks and meningoencephaloceles originating in the lateral recess of the sphenoid sinus can be challenging to manage. The traditional “direct line” transpterygoid approach through the pterygopalatine fossa (PPF) is technically demanding, time consuming, and risks injury to important structures, which can result in significant morbidity including dry eye, dry nose, and facial numbness. The skull base team at Cleveland Clinic has developed a modified transpterygoid approach (MTPA) to access the lateral sphenoid sinus, which completely avoids dissection of the PPF contents.¹ This innovative technique was founded on the notion that endoscopic surgeons now have greater facility with angled endoscopes, and it leverages advances in angled and malleable instrumentation that allow for surgeons to more effectively “operate around corners.” In the MTPA, the face of the sphenoid and anterior junction of the pterygoid plates are removed, allowing for mobilization of the PPF contents with the periosteum intact. Angled instrumentation is then used to resect the meningoencephalocele and repair the skull base defect in the lateral recess.
The skull base team recently published the findings of a multiinstitutional study using this novel technique.2 Patients with lateral sphenoid recess CSF leaks and meningoencephaloceles between 2014 and 2020 who underwent the MTPA at 2 academic medical centers were identified. Repair techniques and outcomes were evaluated.
| Characteristics | Patient Number |
|---|---|
| Age, mean (SD) | 53 ± 13.6 |
| Male | 3 (9.1%) |
| Female | 30 (90.9%) |
| Body mass index, mean (SD) | 39.5 ± 9.4 |
| Laterality of skull base defect (%) | |
| Right | 14 (42.4%) |
| Left | 19 (57.6%) |
| Meningoencephalocele on imaging (%) | |
| Present | 23 (69.7%) |
| Absent | 10 (30.3%) |
Thirty‐three patients underwent the MTPA for management of lateral sphenoid sinus meningoencephaloceles. Skull base reconstruction was performed using a free mucosal graft (24/33, 72.7%), nasoseptal flap (4/33, 12.1%), bone grafts (3/33, 9.1%), and abdominal fat grafts (2/33, 6.1%). Lumbar drains and perioperative intracranial pressure measurements were routinely employed.
| Characteristics | Patient Number |
|---|---|
| Method of skull base repair (%) | |
| Free mucosal graft | 24 (72.7%) |
| Nasoseptal flap | 4 (12.1%) |
| Bone graft | 3 (9.1%) |
| Abdominal fat | 2 (6.1%) |
| CSF pressure measurement, mean (SD) | |
| Intraoperative | 20.1 ± 5.7 |
| Postoperative (day 3) | 22.1 ± 7.7 |
| History of meningitis preoperatively (%) | |
| No | 27 (81.8%) |
| Yes | 6 (18.2%) |
CSF = cerebrospinal fluid
Postoperative complications were uncommon and included 3 patients (9.7%) with temporary maxillary nerve (V2) anesthesia, 1 patient (3.2%) with prolonged V2 anesthesia, and 1 patient (3.2%) with subjective dry eye, all of which resolved at 9 months postoperatively. There were no recurrent CSF leaks, resulting in a 100% success rate. Average follow‐up was 13 months.
| Postoperative Outcomes | Patient Number |
|---|---|
| CSF leak repair (%) | |
| Success | 33 (100%) |
| Failure | 0 (0%) |
| Postoperative complications (%) | |
| Short‐term (< 6 months) V2 anesthesia | 3 (9.7%) |
| Long‐term (> 6 months) V2 anesthesia | 1 (3.2%) |
| Subjective dry eye | 1 (3.2%) |
| Postoperative hemorrhage | 0 (0%) |
| V2‐related neuropathic pain | 0 (0%) |
| Recurrent CSF leak | 0 (0%) |
CSF = cerebrospinal fluid, V2 = maxillary nerve
The study demonstrated that the MTPA reduces morbidity and greatly simplifies access to the lateral sphenoid sinus for the management of CSF leaks and meningoencephaloceles, without compromising exposure. This technique avoids the need for extensive PPF dissection and should be considered for the management of benign lesions involving the lateral sphenoid sinus.
