Robotic Spine Surgery: Systematic Review of Common Error Types and Best Practices.

BACKGROUND AND OBJECTIVES: Robotic systems have emerged as a significant advancement in the field of spine surgery. They offer improved accuracy in pedicle screw placement and reduce intraoperative complications, hospital length of stay, blood loss, and radiation exposure. As the use of robotics in spine surgery continues to grow, it becomes imperative to understand common errors and challenges associated with this new and promising technology. Although the reported accuracy of robot-assisted pedicle screw placement is very high, the current literature does not capture near misses or incidental procedural errors that might have been managed during surgery or did not alter treatment of patients. We evaluated errors that occur during robot-assisted pedicle screw insertion and identify best practices to minimize their occurrence. METHODS: In this systematic review, we characterized 3 types of errors encountered during robot-assisted pedicle screw insertion-registration errors, skiving, and interference errors-that have been reported in the literature. RESULTS: Our search yielded 13 relevant studies reporting robot-assisted screw errors. Nine studies reported registration errors, with 60% of failed screws in those studies caused by registration issues. Seven studies highlighted skiving errors; 26.8% of the failed screws in those studies were caused by skiving. Finally, interference errors were reported in 4 studies, making up 19.5% of failed screws. CONCLUSION: On the basis of these findings, we suggest best practices-including close attention to preoperative planning, patient positioning, image registration, and equipment selection-to minimize the occurrence of these errors. Awareness of how errors occur may increase the safety of this technology.

Mechanical thrombectomy beyond the circle of Willis: efficacy and safety of different techniques for M2 occlusions.

BACKGROUND: M2 segment occlusions represent approximately one-third of non-lacunar ischemic stroke and can lead to permanent neurological deficits. Various techniques are available for mechanical thrombectomy beyond the circle of Willis, but data evaluating their effectiveness and safety are lacking. METHODS: A retrospective review of patients with ischemic stroke undergoing mechanical thrombectomy for M2 occlusions from 13 centers in North American and Europe was performed. Tandem or multiple-territory occlusions were excluded. The primary outcome was 90-day modified Rankin Scale and reperfusion rates across stent-retriever, direct aspiration and combined techniques. RESULTS: There were 465 patients (mean age 71.48±14.03 years, 53.1% female) with M2 occlusions who underwent mechanical thrombectomy. Stent-retriever alone was used in 133 (28.6%), direct aspiration alone in 93 (20.0%) and the combined technique in 239 (51.4%) patients. Successful reperfusion was achieved with the combined technique in 198 (82.2%; OR 2.6 (1.1-6.9)), with stent-retriever alone in 112 (84.2%; OR 9.2 (1.9-44.6)) and with direct aspiration alone in 62 (66.7%; referencecategory). Intraprocedural subarachnoid hemorrhages (iSAH) were 36 (7.7%) and were more likely to occur in patients treated with the stent-retrievers (OR 5.0 (1.1-24.3)) and combined technique (OR 4.6 (1.1-20.9)). Good clinical outcome was achieved in 260 (61.8%) patients, while 59 (14.0%) patients died. Older age, higher baseline NIHSS (National Institutes of Health Stroke Scale), parenchymal hemorrhage and iSAH were associated with poor outcome while successful recanalization and higher baseline ASPECTS (Alberta Stroke Program Early CT Score) were associated with good outcome. No differences were found among the three techniques in terms of clinical outcome. CONCLUSION: Stent-retrievers and a combined approach for M2 occlusions seem more effective than direct aspiration, but with higher rates of iSAH. This leads to no detectable difference in clinical outcome at 3 months.

Anticoagulant Medications and Operative Subdural Hematomas: A Retrospective Cohort Study Evaluating Reoperation Rates.

BACKGROUND: Anticoagulant therapy is common and complicates the operative management of acute and mixed-density subdural hematomas (SDHs). The risk of reoperation inferred by anticoagulant (AC) medication and the ability of reversal agents to reduce hemorrhagic complications in patients presenting with AC-associated SDHs are not fully understood. METHODS: Data were collected for 288 consecutive patients treated with craniotomy or craniectomy for evacuation of an acute or mixed-density SDH between 2012 and 2017 at 2 academic institutions. Primary end points were reoperation within 30 days and functional outcome at discharge. Groups were compared based on AC use. Logistic regression models were used to identify predictors of reoperation and functional outcome at discharge. RESULTS: Forty-six patients on ACs and 242 with no AC history were analyzed. All patients on AC underwent AC reversal before hematoma evacuation. Reoperation rates between groups were not significantly different (10.9% vs. 12.4%; P = 1.00); however, time to reoperation was significantly shorter in those on ACs (0.8 ± 1.1 days vs. 6.8 ± 10.4 days; P = 0.04). Aspirin use was independently associated with the need for reoperation (odds ratio, 3.05; confidence interval, 1.30-7.19; P = 0.01). Patients taking ACs were significantly older, had more medical comorbidities and were more likely to have a higher modified Rankin Scale score at discharge. CONCLUSIONS: Anticoagulant use was not associated with an increased reoperation rate, suggesting that reversal of AC may have eliminated the hemorrhagic risk conferred by these medications. Patients on ACs were significantly older, harbored more medical comorbidities, and had a worse functional outcome at discharge.

Antiplatelet Medication and Operative Subdural Hematomas: A Retrospective Cohort Study Evaluating Reoperation Rates.

BACKGROUND: Antiplatelet therapy is common and complicates the operative management of subdural hematomas (SDH). The risk of reoperation inferred by antiplatelet medication and the ability of platelet transfusion to reduce hemorrhagic complications in patients presenting with antiplatelet associated SDHs are poorly defined. METHODS: We performed a retrospective review of consecutive patients treated with craniotomy or craniectomy for evacuation of an acute or mixed-density SDH between 2012 and 2017 at 2 academic institutions. Exclusion criteria included anticoagulant therapy, thrombocytopenia, and/or international normalized ratio >1.3. Clinical and radiographic data were collected; primary endpoint was reoperation within 30 days. Logistic regression models were used to identify predictors of reoperation. RESULTS: A total of 195 patients were included: 86 patients on antiplatelet medication and 109 with no antithrombotic history. Overall, 24 (12.3%) of patients required a reoperation. Reoperation rate in patients on antiplatelet medication was not significantly different than those not on antithrombotics (14.0% vs. 11.0%, P = 0.53). Patients taking antiplatelet medication were significantly older, more likely to have medical comorbidities, and more likely to receive preoperative platelet transfusion (36.0% vs. 3.7%, P < 0.001). Of patients taking antiplatelet medications, there was no difference in reoperation rate between those patients receiving preoperative platelet transfusion and those not receiving transfusion (16.1% vs. 12.7%, P = 0.75). CONCLUSIONS: Antiplatelet medication was not a significant predictor of reoperation following evacuation of an acute or mixed-density SDH. In patients on antiplatelet medication, preoperative platelet transfusion did not reduce reoperation rates.

Surgical Management of Giant Retrocerebellar Arachnoid Cysts with a Cystoventricular Stent After Long-Term, Independent, and Simultaneous Intracystic and Intraventricular Pressure Monitoring.

BACKGROUND: Outcomes of surgical treated patients with giant retrocerebellar arachnoid cysts with the available typically preferred techniques frequently are unsatisfactory. OBJECTIVES: We hypothesized that a pressure gradient may exist between the cyst and the ventricular system that may be responsible for the posterior fossa-related symptoms and headaches, and, if so, that connecting both cavities by means of a shunt catheter (i.e., cystoventricular stent), the pressure differences would equilibrate and the symptoms resolve. To prove our hypothesis, we decided to simultaneously monitor the intracyst pressure and the intraventricular pressure. METHODS: This was a retrospective chart review analysis of 5 consecutive patients with giant retrocerebellar arachnoid cysts treated between 2014 and 2016. RESULTS: Four patients underwent 3 days of continuous intracranial pressure monitoring, and 1 patient was monitored in the surgical suit. Cyst and ventricular pressures tended to be within normal accepted values in all patients, and a pressure gradient was noticed only in the 2 patients with previous cyst surgeries. All patients were treated with a cystoventricular stent, and overall, had long-term sustained good outcomes, with resolution of symptoms in 3 and significant improvement in 2. CONCLUSIONS: Patients with symptomatic large retrocerebellar arachnoid cysts do not seem to have increased intracranial pressure, and regardless of the presence or absence of a pressure gradient between the cyst and the ventricles, a cystoventricular stent seems to be effective and the best first surgical option to offer.