Microsurgical anatomy of the anterior cerebral artery and the arterial supply of the cingulate gyrus.

PURPOSE: The cingulate gyrus is a potential surgical area to treat tumours, psychiatric diseases, intractable pain and vascular malformations. The aim of the study was to define the topographic anatomy and arterial supply of the cingulate gyrus located on the medial surface of the cerebral hemisphere. METHODS: We studied thirty-six hemispheres, each hemisected in the midsagittal plane. The vertical thickness of the cingulate gyrus was measured at the anterior commissure (AC), posterior commissure (PC), and genu levels of the corpus callosum. The branches of the anterior and posterior cerebral arteries supplying each zone were noted separately. The arterial pathways were transformed to digital data in AutoCAD to identify the condensation and reduction areas. RESULTS: The mean AC-PC distance was 27.17 ± 1.63 mm. The thinnest region was the genu level of the corpus callosum (10.29 mm). The superior internal parietal artery (SIPA), inferior internal parietal artery (IIPA) and pericallosal artery (PrCA) supplied all zones of the cingulate gyrus. The anterior zone received the greatest supply. The arterial condensation and reduction areas on both sides of cingulate gyrus and its x, y, and z coordinates specified. CONCLUSIONS: The target cingulotomy (TC) area was determined for anterior cingulotomy. The properties of the TC area are that the thinnest region of the cingulate gyrus is supplied relatively less than other areas and is close to the anterior cingulotomy areas in the literature. The arterial reduction area (ARA) was found to be suitable for corpus callosotomy in terms of avoiding haemorrhage.

Morphology of the trigeminal ganglion: anatomical structures related to trigeminal radiofrequency rhizotomy.

BACKGROUND: Trigeminal neuralgia is the most common example of craniofacial neuralgia. Its etiology is unknown and is characterized by severe episodes of paroxysmal pain. The trigeminal ganglion and its adjacent anatomical structures have a complex anatomy. The foramen ovale is of great importance during surgical procedures such as percutaneous trigeminal rhizotomy for trigeminal neuralgia. OBJECTIVE: We aimed to identify the anatomical structures associated with the trigeminal ganglion and radiofrequency rhizotomy on cadavers and investigate their relationship with the electrodes used during rhizotomy to determine the contribution of the electrode diameter and length to the effectiveness of the lesion formation on the ganglion. METHODS: Five fresh-frozen cadaver heads injected with red silicone/latex were used. A percutaneous puncture was made by inserting of a cannula through the foramen ovale to create a pathway for electrodes. The relationships between the electrodes, Meckel's cave, trigeminal ganglion, and neurovascular structures were observed and morphometric measurements were obtained using a digital caliper. RESULTS: Trigeminal ganglion, therefore the electrode in its final position, shows proximity with important anatomical structures. The electrode was inserted posteriorly into the foramen ovale in all of the specimens and was located on the retrogasserian fibers. This study revealed that the electrodes targeting the ganglion and passing through the foramen ovale may cause a radiofrequency lesion due to the contact effect of the dura itself pressing on the electrode. Pushing the cannula beyond the petroclival angle may result in puncturing of the dura propria and moving further away from the target area. CONCLUSION: The success of radiofrequency rhizotomy is directly related to the area affected by the lesion. Understanding the mechanism of action underlying this procedure will ensure the effectiveness, success, and sustainability of the treatment.

Is Placing Prophylactic Dural Tenting Sutures a Dogma?

OBJECTIVE: In this study, we investigated if and when dural tenting sutures are necessary during craniotomy. METHODS: Results from 437 patients 18-91 years of age (average, 43.5 years) who underwent supratentorial craniotomy between 2014 and 2019 were evaluated. The patients were categorized into 1 of 3 groups: patients who had at least 3 prophylactic dural tenting sutures placed before opening of the dura (group 1); patients who had at least 3 dural tenting sutures placed after surgery was completed, during closure (group 2); or patients who had no dural tenting sutures (group 3 [control]). All such sutures in groups 1 and 2 were placed in the circumference of the craniotomy and dural junction. No central dural tenting sutures were placed in any of the patients. RESULTS: Among the 437 patients, 344 underwent surgery for the first time and 93 were undergoing a second surgery. Cranial computed tomography imaging was performed for each patient 1 hour, 3 days, and 1 month after surgery. In group 1, 3 patients had a cerebral cortex contusion and 2 patients had acute subdural hematoma after the sutures were placed. In groups 2 and 3, none of the patients had a cerebral cortex contusion or acute subdural hematoma. Fewer complications were observed when dural tenting sutures were placed during postsurgical closure. CONCLUSIONS: Placing dural tenting sutures is an important technique for ensuring hemostasis. However, when not needed, they seem to cause inadvertent complications. As our results suggest, knowing when and where to use them is equally important.

Contralateral Subfrontal Supraorbital Approach for Microsurgical Resection of Optic Canal Meningioma.

ABSTRACT: Meningiomas are mostly benign tumors of the central nervous system. Recurrence can be seen in clinoidal meningiomas especially extending into optic canal. We present a patient with a history of left clinoidal meningioma excision via pterional approach and recurrence purely in left optic canal. Optic canal drilling is necessary for complete removal of these type of tumors. Contralateral subfrontal approach with an eyebrow incision and a keyhole supraorbital craniotomy was used for this patient. Contralateral viewing of the surgical area provided direct angles and created better workspace for the surgeon. Total excision was achieved with no additional neurological deficits in the postoperative period. This approach can be used with its wide exposure of surgical site, potential space usage without need of retraction and better postoperative scar healing.

Endonasal endoscopic management of the craniopharyngeal canal meningoencephalocele using a nasoseptal flap in a 6-month-old infant.

Endonasal endoscopic approach (EEA) has become a routine and effective method for the management of large skull base defects in adults and increasingly in older pediatric populations despite their challenging narrow transnasal corridors. To our knowledge, this is the first report in the literature of a large craniopharyngeal canal (CC) meningoencephalocele in a 6-month-old infant managed purely through EEA, also by utilizing a pedicled nasoseptal flap (PNF).

Timing of Shunt Insertion in Children with Neural Tube Defects and Hydrocephalus: A Clinical Study.

AIM: To define the optimal time of shunt insertion in patients with neural tube defects and hydrocephalus. MATERIAL AND METHODS: In total, 71 patients who underwent operation for neural tube defects and hydrocephalus were retrospectively evaluated between 2012 and 2018. The first group comprised 43 patients who underwent operation at different times (in 10 days after the repair of defect), and the second group comprised 28 patients who underwent operation at the same time. Ruptured and unruptured sacs were immediately considered and operated within 72 hours. RESULTS: In the first group, 43 patients underwent operation for neural tube defect after birth. Ventriculoperitoneal shunt insertion was performed 10 days after wound healing. Five (11.6%) patients were diagnosed with meningitis on follow-up. Shunt infection or meningitis was not observed on follow-up in the second group, which comprised patients who underwent operation at the same time. CONCLUSION: The lowest complication rate existed in hydrocephalus management when shunt insertion and myelomeningocele repair procedures were performed at the same time.

Microsurgical Management of Ventral Intradural-Extramedullary Cervical Meningiomas: Technical Considerations and Outcomes.

OBJECTIVE: Cervical meningiomas are uncommon intradural-extramedullary tumors that have a tendency to be situated anterior to the spinal cord. The optimal surgical corridor to reach purely ventral cervical meningiomas has not been established. This article presents a series of patients with ventral cervical meningiomas treated via 1 of 2 microneurosurgical approaches: the anterior approach with corpectomy and fusion or the posterolateral approach. METHODS: Eight patients who underwent surgical resection of solitary, histopathologically confirmed, intradural-extramedullary cervical meningiomas of purely ventral location were retrospectively examined. Preoperative and postoperative Nurick scores quantified the degree of ambulatory function. Patients were followed for an average of 2.1 years after surgery. Postoperative imaging was performed to determine the extent of resection and to assess for tumor recurrence. RESULTS: Two patients with lower cervical meningiomas underwent resection via an anterior approach with single-level corpectomy and fusion. Six patients were treated via a posterolateral approach including ipsilateral hemilaminectomy and partial facetectomy without fusion. No intraoperative or postoperative complications were observed. Gross total resection was achieved in 8 of 8 patients, although 1 patient exhibited tumor recurrence. Improvement in ambulatory function was observed in all patients. CONCLUSIONS: Purely ventral cervical meningiomas are uncommon and pose unique technical challenges for neurosurgeons. We document favorable outcomes from 2 cases of lower cervical meningioma treated via an anterior approach and 6 cases of upper cervical tumors treated via a posterolateral approach. This series demonstrates operative considerations for effectively managing ventral cervical meningiomas.