Relieving Brain Stem Compression Secondary to Vertebrobasilar Dolichoectasia Using a Carotid Patch Graft Sling and Anterolateral Mobilization: A Technical Note

Background Vertebrobasilar dolichoectasia can cause brain stem compression as well as cranial nerve deficits. Multiple methods have been used which mobilizes the vertebrobasilar system anteriorly or anteromedially toward the clivus. Often, however, the curve of the dolichoectatic vessel is more readily mobilized laterally. We describe a simpler novel technique to decompress the brain stem with an anterolaterally directed sling.

Objective To present a novel sling technique for brain stem decompression secondary to vertebrobasilar dolichoectasia.

Methods Patients who underwent vertebrobasilar decompression were identified from the prospectively maintained neurosurgery database and their medical records and imaging were reviewed retrospectively. Outcomes were assessed at 3 months postoperative.

Results

Surgical Technique Vertebrobasilar decompression was performed in two patients. In each case, a far lateral craniectomy was performed to access the intradural vertebral artery. Neuromonitoring of the lower cranial nerves, somatosensory evoked potentials, and motor evoked potentials was obtained throughout the surgery. The vertebral artery was identified and mobilized. A sling made from a Hemashield vascular patch (Atrium Medical Corporation, Hudson, New Hampshire, United States) and wrapped around the vertebral artery. The two ends of the sling were sutured together using 4–0 Surgilon (Medtronic, Minneapolis, Minnesota, United States) and the sling was then pulled through the dural opening and screwed to the occipital condyle using cranial plating screws (DePuy Synthes, West Chester, Pennsylvania, United States ). The dural leaflets were approximated and an onlay duraplasty performed.

Outcomes Both patients had radiographic improvement in the degree of brain stem compression as well as improvement in presenting symptoms.

Case Example A 79-year-old man with a history of hypertension, stage III chronic kidney disease, and sensorineural hearing loss presented with 6 months of subacute progressive gait instability, right hemiparesis, and dysphagia. He rapidly developed left facial weakness as well as respiratory insufficiency. CTA demonstrated significant left vertebral artery dolichoectasia and resultant brain stem compression. He underwent left far lateral craniectomy and carotid patch graft sling. He was discharged to a long-term acute care facility with a tracheostomy on blow-by oxygen. Two months after surgery, he is walking with assistance with improved hemiparesis and left facial weakness. He has improved respiratory function and is working toward decannulation.

Conclusion Vertebrobasilar dolichoectasia can cause symptoms related to compression of the brain stem and cranial nerves. Multiple techniques are available for decompression. We describe a technique that utilizes a far lateral craniectomy and a carotid patch graft sling secured to the occipital condyle. This provides anterolateral mobilization of the vertebral artery. The Hemashield graft is composed of woven polyester and bovine collagen. It is a thin, knitted graft which handles quite well and provides sufficient tensile strength to mobilize the artery. This method allows for significant decompression of the cervicomedullary junction.