End-to-end anastomosis of the posterior inferior cerebellar artery before excision of a meningioma involving the lower clivus and the foramen magnum. Case report

Case report: Unilateral paralysis of the hypoglossal nerve as the only clinical sign of clivus meningioma - a case report and literature review

Introduction

Clivus meningiomas are benign tumors that occur at the skull base in the posterior cranial fossa. Symptoms usually progress several months or years before diagnosis and may include: headache, vertigo, hearing impairment, ataxia with gait disturbances, sensory problems. In the neurological findings, paralysis of the lower cranial nerves is most often seen, which in the later course can be accompanied by cerebellar and pyramidal signs until the development of a consciousness impairment.

Case presentation

We presented the case of a patient who at the time of diagnosis had only unilateral hypoglossal nerve paralysis with dysarthria and mild dysphagia. After the neurosurgical procedure, pathohistological analysis confirmed meningothelial meningioma.

Conclusion

Early recognition of clivus tumors, which include meningiomas, is necessary in order to implement an adequate therapeutic procedure and prevent further deterioration of the patient's condition.

The re-anastomosis end-to-end bypass technique: a comprehensive review of the technical characteristics and surgical experience

Re-anastomosis end-to-end bypass is a straightforward subtype of intracranial-intracranial reconstruction technique that has been utilized to treat complex aneurysms and skull base tumors. This simple technique involves connecting the cut ends of an afferent and efferent artery under added tension after excising the lesion. The current study aims to provide a detailed description of the technical pitfalls, ideal anatomical sites and indications, and clinical outcomes for intracranial complex disorders. A literature search was performed using the terms "intracranial-intracranial bypass," "re-anastomosis bypass," "reconstructive bypass," "end-to-end bypass," and "end-to-end anastomosis" to identify pertinent articles. Articles involving end-to-end re-anastomosis combined with other bypass methods were excluded. Computer-tablet-drawn illustrations of this technique are provided to enhance comprehension. Eighty-six patients who met our search and inclusion criteria were identified between 1978 and the present. However, comprehensive descriptions of medical records and neuroimaging were available in only 41 cases (40 complex aneurysms and a skull base tumor). Of 40 reported cases of complex cerebral aneurysms treated by this technique, the overall rate of full recovery without complication is 87.5% (35/40). Meanwhile, all aneurysms were completely eliminated from the circulation, with 92.5% of bypasses being patent. End-to-end re-anastomosis remains a simple modality in the microsurgical bypass armamentarium. Safe and effective surgical outcomes can be achieved in select cases that rarely involve perforators or branches.

Foramen magnum meningiomas: surgical results and risks predicting poor outcomes based on a modified classification

OBJECTIVE This study aimed to evaluate neurological function and progression/recurrence (P/R) outcome of foramen magnum meningioma (FMM) based on a modified classification. METHODS This study included 185 consecutive patients harboring FMMs (mean age 49.4 years; 124 females). The authors classified the FMMs into 4 types according to the previous classification of Bruneau and George as follows: Type A (n = 49, 26.5%), the dural attachment of the lesion grows below the vertebral artery (VA); Type B (n = 39, 21.1%), the dural attachment of the lesion grows above the VA; Type C1 (n = 84, 45.4%), the VA courses across the lesion with or without VA encasement or large lesions grow both above and below the bilateral VA; and Type C2 (n = 13, 7.0%), Type C1 plus partial/total encasement of the VA and extradural growth. RESULTS The median preoperative Karnofsky Performance Scale (KPS) score was 80. Gross-total resection (GTR) was achieved in 154 patients (83.2%). Lower cranial nerve morbidity was lowest in Type A lesions (16.3%). Type C2 lesions were inherently larger (p = 0.001), had a greater percentage of ventrolateral location (p = 0.009) and VA encasement (p < 0.001), lower GTR rate (p < 0.001), longer surgical duration (p = 0.015), higher morbidity (38.5%), higher P/R rate (30.8%, p = 0.009), and poorer recent KPS score compared with other types. After a mean follow-up duration of 110.3 months, the most recent follow-up data were obtained in 163 patients (88.1%). P/R was observed in 13 patients (7.2%). The median follow-up KPS score was 90. Compared with preoperative status, recent neurological status was improved in 91 (49.2%), stabilized in 76 (41.1%), and worsened in 18 (9.7%) patients. The multivariate Cox proportional hazard regression model demonstrated Type C2 (HR 3.94, 95% CI 1.04-15.0, p = 0.044), nontotal resection (HR 6.30, 95% CI 1.91-20.8, p = 0.003), and pathological mitosis (HR 7.11, 95% CI 1.96-25.8, p = 0.003) as independent adverse predictors for tumor P/R. Multivariate logistic regression analysis identified nontotal resection (OR 4.06, 95% CI 1.16-14.2, p = 0.029) and pathological mitosis (OR 6.29, 95% CI 1.47-27.0, p = 0.013) as independent risks for poor outcome (KPS score < 80). CONCLUSIONS The modified classification helped to predict surgical outcome and P/R in addition to the position of the lower cranial nerves. Preoperative imaging studies and neurological function should be reviewed carefully to establish an individualized management strategy to improve long-term outcome.

Microsurgical anatomy of cerebral revascularization. Part II: Posterior circulation

Object. Revascularization is an important component of treatment for complex aneurysms, skull base tumors, and vertebrobasilar ischemia in the posterior circulation. In this study, the authors examined the microsurgical anatomy related to cerebral revascularization in the posterior circulation and demonstrate various procedures for bypass surgery.

Methods. The microsurgical anatomy of cerebral and cerebellar vessels as they relate to revascularization procedure and techniques, including extracranial-to-intracranial bypass grafting, arterial interposition grafting, and side-to-side anastomosis, were examined by performing stepwise dissections in 22 adult cadaveric specimens. The arteries and veins in the specimens were perfused with colored silicone.

Dominant cerebral and cerebellar revascularization procedures in the posterior circulations include superficial temporal artery (STA)—posterior cerebral artery (PCA), STA—superior cerebellar artery (SCA), occipital artery (OA)—anterior inferior cerebellar artery, OA—posterior inferior cerebellar artery (PICA), and PICA—PICA anastomoses. These procedures are effective in relatively small but critical areas including the brainstem and cerebellum. For revascularization of larger areas a saphenous vein graft is used to create a bypass between the PCA and the external carotid artery. Surgical procedures are generally difficult to perform in deep and narrow operative spaces near critical vital structures.

Conclusions. Although a clear guideline for cerebral revascularization procedures has not yet been established, it is important to understand various microsurgical techniques and their related anatomical structures. This will help surgeons consider surgical indications for treatment of patients with vertebrobasilar ischemia caused by aneurysms, tumors, or atherosclerotic diseases in the posterior circulation.

Cerebral revascularization performed using posterior inferior cerebellar artery-posterior inferior cerebellar artery bypass. Report of four cases and literature review

Cerebral revascularization is often required for the surgical treatment of complex intracranial aneurysms. In certain anatomical locations, vascular anatomy and redundancy make in situ bypass possible. The authors present four patients who underwent revascularization performed using the rarely reported posterior inferior cerebellar artery (PICA)-PICA in situ bypass after their aneurysms had been trapped. At Barrow Neurological Institute, between 1991 and the present, four male patients underwent PICA-PICA by-passes to treat aneurysms involving the vertebral artery, the PICA, or both. The mean age of these patients was 34 years (range 5-49 years). Follow-up studies revealed patent bypasses and no evidence of infarction. Patient outcomes were excellent or good. Multiple surgical techniques have been described for revascularization of at-risk cerebral territories. Often, the blood supply must be derived from extracranial sources through a mobilized pedicle or interposited graft. Certain anatomical locations such as the vertebrobasilar junction, the anterior circle of Willis, and the middle cerebral artery bifurcation are amenable to in situ bypass because there is vessel redundancy or proximity to the contralateral analogous vessel. The advantages of an in situ bypass include one suture line, a short bypass distance, and a close match with the caliber of the recipient graft. Although technically challenging, this technique can be successful and should be considered for appropriate candidates.