The Microcisternal Drainage Technique

BACKGROUND: Microsurgical dissection of arachnoid cisterns requires a combination of anatomic knowledge and microsurgical skill. The latter relies on experience and microsurgical dexterity, which depend on visual identification of cisternal microvasculature. We describe a novel standardized operative sequence to allow for bloodless arachnoid dissection when cisternal anatomy is challenging. METHODS: We used the reported technique in 1928 cases over the past 5 years (2018-2022). The outer arachnoid was incised to enter the cisternal space. A cotton pledget was placed in contact with an inner membrane and gently pushed laterally and superficially with the suction cannula at medium suction power. When the arachnoid membranes dried, arachnoid trabeculae were cut and microvasculature were released at the convexity of their loops and gently transposed off the dissection trajectory. The same principle was used to release parent and perforating arteries from the aneurysm dome. RESULTS: The microcisternal drainage technique enabled safe and efficient access through adhered arachnoid in all cases. A complex anterior communicating artery aneurysm in a 52-year-old lady demonstrated the use of the microcisternal drainage technique during access through the pericallosal cistern. This technique was used in all cases where cisternal dissection was needed. CONCLUSIONS: The microcisternal drainage technique uses deliberate and strategic suction, dynamic retraction, and nuanced scissor cuts to enable precise and bloodless microdissection of adherent arachnoid cisterns. This technique combines common neurosurgical maneuvers in a novel standardized sequence to improve efficiency and safety during arachnoid dissection

High Cervical Carotid Endarterectomy–Outcome Analysis

Objective Carotid endarterectomy (CEA) for high cervical internal carotid artery stenosis is considered to be technically demanding because of the difficulty in dissecting the distal end. We report the surgical technique and outcome analysis of CEA for high cervical lesions. Methods We retrospectively analyzed the records of 98 patients treated by CEA from December 2013 to June 2018. The plaque positions rostral to the C2 vertebral level was defined as the high cervical lesions (n = 34). The surgical technique is to successfully expose the distal end, as follows: 1) extend the skin incision; 2) expose the great auricular nerve maximally; 3) dissect between the SCM and parotid gland fascia; 4) resect the internal deep cervical lymph nodes; and 5) retract the digastric muscle, hypoglossal nerve, and occipital artery. Results There were 8 cases (high cervical group, 4 cases; non-high cervical group, 4 cases) of postoperative diffusion-weighted imaging high signal and 6 cases (high cervical group, 3 cases; non-high cervical group, 3 cases) of symptomatic ischemic lesion. Four cases belonged to the technique-related cerebral infarction group and 4 cases to the perioperative-related cerebral infarction (PRCI) group. High cervical lesion is not considered to be a risk factor for either PRCI (P = 0.610) or technique-related cerebral infarction (P = 0.610). The difference of the diastolic blood pressure between the preoperative period and the second postoperative day showed a risk factor of PRCI (P = 0.033). Conclusions The surgical outcomes for high cervical lesions are equivalent to that of non-high cervical lesions. Excessive blood pressure management from the early postoperative days is a risk of PRCI.Peer reviewe

Basal vein of Rosenthal classification: the key to venous outflow of the deep sylvian fissure

OBJECTIVE: Mastery of sylvian fissure dissection is essential to access lesions within the deep basal cisterns. The deep sylvian vein and its tributaries play a major role during access to and beyond the carotid cistern through the sylvian fissure and determine the complexity of microdissection. Preserving the venous outflow during sylvian fissure dissection is the best reliable strategy to prevent postoperative venous strokes or venous hypertension. The authors report the role of the basal vein of Rosenthal (BVR) in the venous outflow pattern of the deep sylvian cistern. METHODS: The authors analyzed 262 consecutive surgical cases involving sylvian fissure dissection from 2015 to 2017. Inclusion criteria were complete sylvian fissure dissection for the treatment of intracranial aneurysms. Exclusion criteria were giant size (aneurysm diameter \u3e 24 mm), meningitis, subarachnoid hemorrhage within the sylvian cistern, absence of 4D CT angiography, and previous surgery. Retrospective radiological and operative video reviews were carried out to assess the association between the superficial sylvian vein and the BVR. The authors analyzed the course of the BVR and the patterns of venous drainage of the sylvian cistern. The surgical difficulty of sylvian fissure dissection was rated by the authors to study the operative significance of the venous patterns encountered. Two clinical cases are described to illustrate the proposed BVR classification. RESULTS: A total of 97 patients met the selection criteria. The most frequent type of BVR was immature (diameter \u3c 0.5 mm, 68%). When the BVR was incompletely developed or absent (immature type), the deep sylvian veins drained through a middle sylvian vein in 70% of cases, requiring advanced sylvian fissure dissection techniques. However, when the BVR was completely developed (32%), the middle sylvian vein was found in a minority of cases (6%), which allowed for an unobstructed transsylvian corridor. Interrater and test-retest reliability of the surgical difficulty was greater than 0.9. CONCLUSIONS: Preoperative assessment of the BVR anatomy is key to predict the deep sylvian venous pattern. The authors provide objective evidence supporting the reciprocal relationship between the type of BVR and the presence of a middle sylvian vein and the deep sylvian venous outflow. An immature BVR should alert the neurosurgeon of the high likelihood of finding a complex deep venous pattern, which may drive surgical planning

Retrograde Suction Decompression for Clip Occlusion of Internal Carotid Artery Communicating Segment Aneurysms

BACKGROUND: Retrograde suction decompression (RSD) can achieve proximal parent vessel control, improve aneurysm neck visualization, and allow parent vessel reconstruction for direct clipping of internal carotid artery (ICA) aneurysms. The aim of the present study was to describe the technique and surgical results of RSD for direct clipping of ICA communicating segment (C1) aneurysms. METHODS: The clinical data and treatment summaries of 20 patients who underwent RSD-assisted clipping of ICA C1 aneurysms were retrospectively reviewed. Pre- and postoperative three-or four-dimensional computed tomography angiograms, postoperative magnetic resonance images, surgical notes, operative complications, and outcomes were assessed. RESULTS: All patients except one harbored unruptured C1 aneurysms. Extracranial-intracranial graft bypass using the radial artery was performed in five patients. Fifteen patients required temporary clipping of the posterior communicating artery for further reduction of blood back-flow into the aneurysm. All aneurysms were successfully clipped and postoperative three-or four-dimensional computed tomography angiography revealed no major branch occlusion or residual aneurysm. At the 6-month follow-up examination, 19 patients had a good outcome and 1 patient had poor outcome associated with anterior choroidal artery ischemia. No death had occurred at 6-month follow-up examination. CONCLUSIONS: The RSD technique is a useful procedure to achieve proximal vascular control, to soften and shrinkage the aneurysm sac, and to provide a wide and clean operative field allowing safe clip placement. The RSD technique requires special attention to the relationship between the perforators and the aneurysm, and close cooperation between the surgeon and the assistant.Peer reviewe

Microsurgical thrombectomy: where the ancient art meets the new era

Mechanical thrombectomy (MT) is the leading treatment for acute large vessel occlusion (LVO). However, surgical thrombectomy (ST) may have a role in well selected LVO patients where MT failed to re-establish flow, the endovascular route is inaccessible, or where MT is a financially prohibitive or absent option (developing and poor countries). We compared the efficacy and efficiency between ST and MT, and described our operative experience and its potential application in the developing world. Clinical outcomes, procedural times, and efficacy of treatment were compared between the MT and ST of acute LVO between 2012 and 2022. Propensity score-matched analysis was also conducted to compare MT and ST. One-hundred nine patients fulfilled the study criteria (77 MTs vs 32 STs). Factors driving outcome were age (aOR: 0.95, 95%CI, 0.91-0.98), hemisphere side (aOR: 0.38, 95%CI, 0.15-0.96), and DWI-ASPECT (aOR: 1.39, 95%CI, 1.09-1.77) at presentation by the multivariate analysis. Times from door-start of procedure (P = 0.45) and start of procedure-recanalization (P = 0.13) were similar between treatment options. Propensity score-matched analysis found no significant difference for 2 treatment methods about time of door to recanalization (P = 0.155) and outcome (P = 0.221). The prognosticators of thrombectomy for acute LVO in patients with successful recanalization were age, affected hemisphere side, and DWI-ASPECT score. Our evidence shows that the efficacy of ST is similar to that of MT. There should be a place of ST for cases of mechanical failure or tandem cervical ICA and MCA occlusion. ST may be a temporizing LVO treatment option in healthcare systems where MT is inexistent or financially prohibitive to patients

Microsurgical resection of unruptured cerebellar arteriovenous malformation presenting with trigeminal neuralgia

Cerebellar arteriovenous malformations (AVMs) represent 10%–15% of all intracranial AVMs and are associated with a greater risk for hemorrhagic presentation compared with supratentorial AVMs. When they reach the cerebellopontine angle cistern, neurovascular compression syndromes, including trigeminal neuralgia and hemifacial spasm, can occur. Due to the aggressive natural history of cerebellar AVM, an effective treatment strategy is required. In this video, the authors demonstrate the technical nuances of microsurgical resection of an unruptured cerebellar AVM in a 24-year-old female presenting with trigeminal neuralgia. The patient underwent right retrosigmoid craniotomy and complete resection of the AVM with resolution of trigeminal neuralgia. The video can be found here: https://youtu.be/6GmNjgFQwx

Toward a more rationalized use of a special technique for repair of frontal air sinus after cerebral aneurysm surgery: The most effective technique

A craniotomy that passes through the frontal air sinus (FAS) often results in postoperative complications such as infection, cerebrospinal fluid leakage or mucocele formation. A good understanding of FAS reconstruction can decrease the morbidity rate of complications. This study describes the outcomes of treatment and establishes the most effective technique for FAS reconstruction in our institution. We enrolled 107 patients who had a bifrontal craniotomy which exposed the FAS during the operation for an anterior communicating artery (ACoA) aneurysm. Demographic data including the follow-up information were collected and analyzed. The complications after surgery were observed and described in the treatment procedure. The patency of the nasofrontal outflow tract (NFOT) was proved by removal of blood clots and bone dust by irrigation and by direct inspection under a microscope before closure of the frontal sinus mucosa with a monofilament non-absorbable 7/0 material suture. The dura was closed in a watertight fashion and an abdominal fat graft was packed into the FAS cavity. There were 33 male and 74 female patients and the mean age (range) was 64 years (32–90 years). The mean follow-up time was 13 months (1–35 months) and complications were found in only 2 patients. One patient suffered from dislocation of the fat graft and the other patient developed a surgical wound infection. At post-operation the first patient sneezed several times and the second patient suffered from trauma in the nasal area after discharge to home. Both patients were surgically treated and cured. In conclusion, FAS reconstruction from our technique is very effective for the prevention of complications after bifrontal craniotomy. Direct suturing of the frontal sinus mucosa and proving the patency of the NFOT are keys to successful treatment