Endoscopic endonasal transclival clipping of a cerebellar arteriovenous malformation feeding vessel and associated aneurysm; a 2D operative video.

Positioned along the ventral surface of the pons, proximal superior cerebellar artery (SCA) aneurysms account for only 1.7% of all intracranial aneurysms [1]. Unlike more commonly encountered basilar artery aneurysms, patients often experience good outcomes when treated via endovascular coiling or surgical clipping [1,2]. These lesions frequently have a lateral projection and paucity of perforator arteries [2]. With further development of endoscopic endonasal techniques, access to this region is possible via a direct frontal exposure to the ventral brainstem, basilar artery and branching vessels. To date, there are only a limited number of reports describing an endoscopic endonasal transclival (EETC) approach for surgical clipping [3-5]. In this operative video, we detail the surgical clipping of a cerebellar arteriovenous malformation feeding vessel and an associated aneurysm using the EETC approach in a 59-year-old woman who presented with sudden onset of a severe headache. The feeding vessel and aneurysm's midline location, just below the take-off of the SCA made it a good candidate for this surgery. Major steps included in this video include 1) transsphenoidal exposure of and subsequent drilling of the clivus, 2) dural opening into the pre-pontine cistern and dissection of the aneurysm, 3) clipping of the aneurysm, and 4) multi-layered closure of the skull base defect. Overall, the patient tolerated the procedure well and was found to have no residual filling of the aneurysm or the AVM feeding vessel at 2-year follow-up. EETC is a viable surgical option for the treatment of aneurysm located along the midline of the pre-pontine cistern.

Spinal cord stimulation for genitofemoral neuropathy: A case report and review of the literature.

Background: Chronic testicular pain due to genitofemoral neuropathy often becomes refractory to conservative medical therapy. Neurostimulation is a potentially useful treatment option, should the neuropathic pain remain refractory to more invasive procedures such as orchiectomy. We provide a case report of spinal cord stimulation (SCS) for successful treatment of genitofemoral neuropathy and have also reviewed the literature to find similar cases which required a similar treatment paradigm. Case Description: A 42-year-old male underwent SCS for refractory testicular and groin pain. SCS through a four-column, 2 × 8 contact neurostimulator paddle lead, was implanted in the mid-thoracic-9 (T9) vertebral level, providing > 50% testicular pain relief with a decrease in visual analog scale scores from 8-10/10 to 3-4/10. The patient required one adjustment to the stimulation parameters at the time of the 6 weeks follow-up visit due to over-stimulation. He then continued to experience >50% resolution in pain 9 months later. A review of the literature yielded only two similar cases that successfully utilized SCS for treatment of chronic testicular pain. Conclusion: SCS should be considered as a possible treatment option for patients with chronic testicular pain localized to the genitofemoral nerve distribution.

Deep Brain Stimulation Surgery for Essential Tremor in a Patient with Type A Hemophilia.

BACKGROUND: Hemophilia is generally considered a contraindication to deep brain stimulation (DBS) and other elective intracranial surgery because of the elevated risk of perioperative hemorrhage. Two prior case reports have suggested, however, that DBS may be safe in patients with hemophilia who undergo appropriate factor replacement. Here, we describe a third case of DBS surgery for medically refractory essential tremor (ET) in a patient with hemophilia A. CASE DESCRIPTION: A 68-year-old right-handed man with mild hemophilia A presented for a 10-year history of bilateral (right greater than left), medically refractory ET. The patient was considered an appropriate candidate for DBS by a multidisciplinary movement disorders conference, and hematology consultation was obtained. Baseline preoperative laboratory results showed a quantitative factor VIII (FVIII) level of 38%. Perioperative management consisted of daily intravenous bolus doses of recombinant FVIII from the morning of surgery to postoperative day 10. The patient underwent uncomplicated unilateral DBS placement in the left ventralis intermedius thalamus. Intra- and postoperative imaging showed no hemorrhage. His postoperative course was uncomplicated except for a single self-limited episode of hematuria requiring no intervention. CONCLUSIONS: DBS placement for ET may be safe in patients with coexisting hemophilia A if appropriate FVIII replacement is given, which may be delivered as bolus infusions rather than continuous infusion.

Peripheral Nerve Stimulation for Refractory Trigeminal Pain: Recent Single-Institution Case Series With Long-Term Follow-Up and Review of the Literature.

BACKGROUND: Peripheral neurostimulation (PNS) for medically refractory trigeminal pain is an emerging alternative to traditional surgical approaches, with safety and efficacy demonstrated in several retrospective series and a prospective trial currently in progress. Many existing studies suffer from relatively small numbers and short or inconsistent follow-up, making balanced treatment assessment difficult. MATERIALS AND METHODS: Consecutive cases of trial and permanent placement of trigeminal branch stimulation electrodes by a single surgeon from May 2014 through January 2019 were retrospectively reviewed from a prospectively collected database, following the PROCESS guidelines for surgical case series. Outcomes were assessed at six months and at last follow-up. RESULTS: Ninteen patients underwent trial electrode placement, with 15 patients undergoing permanent system placement. The most common diagnoses were idiopathic trigeminal neuralgia Type 2 (N = 8) and trigeminal neuropathic pain (N = 7). Median follow-up was 14 months (range 6-58 months). At last follow-up, 12 of 15 implanted patients (80%) were still receiving stimulation, with mean (median) pain reduction of 52.3% (47.5%). Infection and revision rates were high, although erosion and migration, which have typically plagued trigeminal PNS surgery, did not occur. Implanted systems were well-tolerated, with excellent cosmetic outcomes and high patient satisfaction that proved durable over long follow-up. CONCLUSIONS: We present a single-institution series of PNS for complex craniofacial pain involving the trigeminal nerve. The procedure is safe, effective and durable over at least one year in the large majority of a well-selected patient population.

Revascularization of the Posterior Inferior Cerebellar Artery Using the Occipital Artery: A Cadaveric Study Comparing the p3 and p1 Recipient Sites.

BACKGROUND: Revascularization of the posterior inferior cerebellar artery (PICA) is typically performed with the occipital artery (OA) as an extracranial donor. The p3 segment is the most accessible recipient site for OA-PICA bypass at its caudal loop inferior to the cerebellar tonsil, but this site may be absent or hidden due to a high-riding location. OBJECTIVE: To test our hypothesis that freeing p1 PICA from its origin, transposing the recipient into a shallower position, and performing OA-p1 PICA bypass with an end-to-end anastomosis would facilitate this bypass. METHODS: The OA was harvested, and a far lateral craniotomy was performed in 16 cadaveric specimens. PICA caliber and number of perforators were measured at p1 and p3 segments. OA-p3 PICA end-to-side and OA-p1 PICA end-to-end bypasses were compared. RESULTS: OA-p1 PICA bypass with end-to-end anastomosis was performed in 16 specimens; whereas, OA-p3 PICA bypass with end-to-side anastomosis was performed in 11. Mean distance from OA at the occipital groove to the anastomosis site was shorter for p1 than p3 segments (30.2 vs 48.5 mm; P < .001). Median number of perforators on p1 was 1, and on p3, it was 4 (P < .001). CONCLUSION: Although most OA-PICA bypasses can be performed using the p3 segment as the recipient site for an end-to-side anastomosis, a more feasible alternative to conventional OA-p3 PICA bypass in cases of high-riding caudal loops or aberrant anatomy is to free the p1 PICA, transpose it away from the lower cranial nerves, and perform an end-to-end OA-p1 PICA bypass instead.

3D printed mitral valve models: affordable simulation for robotic mitral valve repair.

OBJECTIVES: 3D printed mitral valve (MV) models that capture the suture response of real tissue may be utilized as surgical training tools. Leveraging clinical imaging modalities, 3D computerized modelling and 3D printing technology to produce affordable models complements currently available virtual simulators and paves the way for patient- and pathology-specific preoperative rehearsal. METHODS: We used polyvinyl alcohol, a dissolvable thermoplastic, to 3D print moulds that were casted with liquid platinum-cure silicone yielding flexible, low-cost MV models capable of simulating valvular tissue. Silicone-moulded MV models were fabricated for 2 morphologies: the normal MV and the P2 flail. The moulded valves were plication and suture tested in a laparoscopic trainer box with a da Vinci Si robotic surgical system. One cardiothoracic surgery fellow and 1 attending surgeon qualitatively evaluated the ability of the valves to recapitulate tissue feel through surveys utilizing the 5-point Likert-type scale to grade impressions of the valves. RESULTS: Valves produced with the moulding and casting method maintained anatomical dimensions within 3% of directly 3D printed acrylonitrile butadiene styrene controls for both morphologies. Likert-type scale mean scores corresponded with a realistic material response to sutures (5.0/5), tensile strength that is similar to real MV tissue (5.0/5) and anatomical appearance resembling real MVs (5.0/5), indicating that evaluators 'agreed' that these aspects of the model were appropriate for training. Evaluators 'somewhat agreed' that the overall model durability was appropriate for training (4.0/5) due to the mounting design. Qualitative differences in repair quality were notable between fellow and attending surgeon. CONCLUSIONS: 3D computer-aided design, 3D printing and fabrication techniques can be applied to fabricate affordable, high-quality educational models for technical training that are capable of differentiating proficiency levels among users.

Chronic Myocardial Ischemia Leads to Loss of Maximal Oxygen Consumption and Complex I Dysfunction.

BACKGROUND: Cardiomyocytes rely heavily on mitochondrial energy production through oxidative phosphorylation. Chronic myocardial ischemia may cause mitochondrial dysfunction and affect ATP formation. Metabolic changes due to ischemia alters cardiac bioenergetics and hence myocardial function and overall bioenergetic state. Here, we evaluate differences in functional status of respiratory complexes in mitochondrial isolates extracted from left atrial appendage tissue (LAA) from patients undergoing cardiac surgery, with and without chronic ischemia. METHODS: Mitochondrial isolates were extracted from LAA in ischemic coronary artery bypass grafting patients (n = 8) and non-ischemic control patients (n = 6) undergoing other cardiac surgery (valve repair/replacement). Coupling and electron transport chain assays were performed using Seahorse XFe 96 (Agilent Technologies, Santa Clara, CA) analyzer. Oxygen consumption rates were measured to calculate respiration states. RESULTS: Respiratory control rate (RCR) in ischemic patients was significantly lower than control patients (6.17 ± 0.27 vs 7.11 ± 0.31, respectively; p < 0.05). This is the result of minimal, non-significant state 3ADP and state 4O changes in chronic ischemia. Complex I respiration is diminished in ischemic tissue (99.1 ± 14.9 vs 257.8 ± 65.2 in control; p < 0.01). Maximal complex I/II respiration ratio was significantly lower in ischemic patients (58.9% ± 5.5% vs 90.9% ± 8.8%; p < 0.05), a difference that was also seen in complex I/IV ratios (p < 0.05). There was no significant difference in complex II/IV ratios between groups. CONCLUSIONS: Ischemic patients have aberrant mitochondrial function, highlighted by a lowered RCR. All ratios involving complex I were affected, suggesting that the insufficient ATP formation is predominantly due to complex I dysfunction. Complex II and IV respiration may be impaired as well, but to a lesser extent.