Advances in Surgery for Metastatic Disease of the Spine: An Update for Oncologists.

STUDY DESIGN: Narrative review. OBJECTIVE: Metastatic spine disease is an increasingly common clinical challenge that requires individualised multidisciplinary care from spine surgeons and oncologists. In this article, the authors describe the recent surgical advances in patients presenting with spinal metastases. METHODS: We present an overview of the presentation, assessment, and management of spinal metastases from the perspective of the spine surgeon, highlighting advances in surgical technology and techniques, to facilitate multidisciplinary care for this complex patient group. Neither institutional review board approval nor patient consent was needed for this review. RESULTS: Advances in radiotherapy delivery and systemic therapy (including immunotherapy and targeted therapy) have refined operative indications for decompression of neural structures and spinal stabilisation, while advances in surgical technology and technique enable these goals to be achieved with reduced morbidity. Formulating individualised management strategies that optimise outcome, while meeting patient goals and expectations, requires a comprehensive understanding of the factors important to patient management. CONCLUSION: Spinal metastases require prompt diagnosis and expert management by a multidisciplinary team. Improvements in systemic, radiation, and surgical therapies have broadened operative indications and increased operative candidacy, and future advances are likely to continue this trend.

Pituitary surgery and COVID.

An effect of the COVID-19 pandemic was the disruption of healthcare systems, especially surgical services provided to the community. Pituitary surgery was especially impacted, given the majority of cases were deemed non-urgent with very few exceptions, and the high risk of viral transmission conferred by the endoscopic endonasal transsphenoidal approach. Patients suffering from pituitary lesions with resultant endocrinopathy or visual symptoms saw their treatment delayed or altered, which had implications on their outcomes and care. This disruption extended to surgical training and the usual functioning of academic units, necessitating changes to curricula and implementation of novel methods of progressing surgical education. This review will explore the effect of the COVID pandemic on pituitary surgery, the experiences of various surgeons as well as the adaptations implemented on the frontlines. The lessons learned from the experience of the pandemic may assist specialists in gleaning insights regarding the care of patients in the future.

Subdural Versus Subgaleal Drain Placement After Minicraniotomy for Chronic Subdural Hematoma.

BACKGROUND AND OBJECTIVES: Surgical evacuation with placement of a postoperative drain is the standard treatment for symptomatic chronic subdural hematoma (cSDH). Subdural and subgaleal drains are equally effective after burrhole craniostomy, but the optimal location of the drain after craniotomy is not clear. We sought to compare the clinical and radiological outcomes of subdural and subgaleal drain placement in patients undergoing minicraniotomy for cSDH. METHODS: A retrospective review of 137 consecutive patients undergoing minicraniotomy for cSDH at a single institution was performed. Cases were stratified by location of postoperative drain. The primary outcome was change in functional status (modified Rankin Score, mRS) at 3 months from preoperative baseline. RESULTS: Among the patient cohort, 24.6% received subgaleal drain placement. After a median follow-up of 105 days, 79.4% (27/34) in the subgaleal group and 57.3% (59/103) in the subdural group (P = .02) had been discharged home. Worse premorbid mRS (P = .002), subdural drain location (P = .004), and decreased consciousness at presentation (Glasgow Coma Scale<15) (P < .002) were independent predictors of a discharge destination other than home. At the 3-month follow-up, the subgaleal group exhibited a mean improvement of 0.77 ± 1.2 points, while the subdural group had a deterioration of 0.14 ± 0.8 points (P < .01). Subgaleal drain location (P < .0001), better preoperative Glasgow Coma Scale (P = .01), and worse premorbid mRS (P = .0003) were independent predictors of improved mRS at 3 months. Recurrence requiring repeat surgery were more common in the subdural (13.6% (14/103) than the subgaleal 2.9% (1/34) group, P = .12), although the absolute incidence rates remained low. CONCLUSION: In patients undergoing minicraniotomy for cSDH, subgaleal drains are associated with shorter hospitalization, greater chance of discharge home, and better functional outcomes than subdural drains.

Tension Pneumocephalus Secondary to Positive Pressure Ventilation Following Endoscopic Endonasal Skull Base Surgery: Three-Year Follow-Up After Implementation of an Institutional Protocol.

BACKGROUND: Tension pneumocephalus (PMC) is a rare and feared complication following the endonasal endoscopic approach (EEA) to skull base procedures. This is a neurosurgical emergency that requires urgent decompression to avoid catastrophic neurologic damage or death. An avoidable cause is the application of positive pressure ventilation (PPV) in EEA patients for postoperative hypoxia. Our institution implemented a hospital-wide protocol in response to this to identify and manage at-risk patients; this paper aims to identify if this protocol was effective in lowering the rates of tension PMC secondary to PPV. RESULTS: In the 3 years following the implementation of the protocol, 110 patients underwent EEAs, from which 1 case of tension PMC (found to be not secondary to PPV) was identified. This is compared with 2 cases of tension PMC secondary to PPV over the preceding 5 years, out of 406 EEA patients. This constitutes a quantifiable reduction in PPV-related tension PMC in both standard and extended approach EEAs, signifying the effective uptake of the protocol. CONCLUSIONS: We found no cases of tension PMC after PPV following EEA skull base surgery in our institution since the implementation of an institution-wide guideline. This underscores the utility of our simple and cost-effective preventative protocol in reducing the overall rates of tension PMC following the inadvertent postoperative application of PPV. Further research is needed to study the comparative risks and benefits of PPV in the post-EEA patient and thus inform future iterations of the protocol.

Quality of life in Prolactinoma: A systematic review.

BACKGROUND: Prolactinomas are common tumours that significantly reduce quality-of-life (QOL) due to sellar mass effect, secondary hypogonadism, and the peripheral effects of prolactin. Understanding the factors that influence QOL would provide insights into therapeutic targets to optimise patient outcomes and improve wellbeing in prolactinoma. METHODS: A systematic review was performed in accordance with the PRISMA statement. Studies that reported patient QoL using validated metrics were included. Bias and methodological rigour were assessed using the MINORS criteria. RESULTS: A total of 18 studies were identified studies were available for review, comprising 877 patients. Most were small cross-sectional studies at high risk of bias. Prolactinoma exhibit worse QOL than healthy controls, particularly mental and psychosocial wellbeing. QOL is also worse than patients with non-functional adenomas, but better than those with Cushing's disease and acromegaly. QOL correlates with prolactin levels, and approaches population baseline with prolonged biochemical control. Dopamine agonists and surgery both improve overall QOL, however improvements are more rapid with surgery. CONCLUSION: Poor quality of life in prolactinoma is multifactorial, related to biochemical control, side effects of therapy, and sellar mass effect. Targeting persistent symptoms, reducing healthcare costs, and reducing side-effects of therapy are avenues to improving QOL in patients with prolactinoma.

Preoperative coil localization for spinal surgery is accurate, safe and effective: a single-centre initial experience.

OBJECTIVE AND STUDY DESIGN: This is a retrospective, descriptive study of consecutive patients undergoing novel preoperative pushable coil localization for spinal surgery, in order to evaluate its feasibility, safety and accuracy. METHODS: Consecutive patients who underwent pre-operative coil marking for spinal surgery at our institution from May 2018 to July 2021 were included. Data were collected for coil placement, accuracy, complications and fluoroscopy usage. Patient demographic and relevant perioperative and procedural data were also collected. RESULTS: A total of 34 patients were identified of which 32 (94%) had complete data and imaging at last clinical follow up, with a mean duration of 13.9 months. There were no incorrect level surgeries performed. There were no coil-related complications found in our cohort. CONCLUSIONS: Preoperative coil placement is an accurate, safe and well-tolerated method for level localization in spinal surgeries.

Recurrent haemorrhagic pontine cavernoma resection via a retrosigmoid microsurgical approach.

BACKGROUND: Brainstem cavernomas occasionally require surgical treatment. Appropriate patient selection and thorough understanding of the anatomy and technical nuances involved in microsurgical resection is a pre-requisite in undertaking these challenging cases. CASE DESCRIPTION: We present a video case of a patient with a recurrent haemorrhagic pontine cavernoma. A step-by-step commentary of surgical footage is provided along with clinical, anatomical and technical learning points pertinent to the safe surgical management of these lesions.

Feasibility of transsphenoidal approach for hypothalamic biopsy based on a radiological evaluation of subchiasmatic corridor dimension.

BACKGROUND: Surgical access to hypothalamic pathologies can be challenging. Recent case series demonstrate that the transsphenoidal approach to the hypothalamus can be safe and effective, however, may not be feasible in all patients. This study aims to investigate the feasibility of the endonasal transsphenoidal suprasellar subchiasmatic (ETSS) approach to the hypothalamus through a radiological evaluation of the subchiasmatic corridor dimension in an adult population. METHODS: A retrospective review of magnetic resonance imaging of the brain was performed on 164 consecutive adult patients at our institution, of which 100 patients were deemed eligible for inclusion. Measurements were obtained at the two narrowest points along the subchiasmatic corridor: the subchiamastic window, which is the face of the subchiasmatic corridor and the midpoint window, which is located in the middle of the subchiasmatic corridor. Based on defined parameters, including the subchasmiatic window width (SW), subchiasmatic window height (SH), midpoint window width (MW), and midpoint window height (MH), patients were dichotomised into groups: patients with subchiasmatic corridor measurements any dimension of less than 3 mm, or patients with dimensions greater than or equal to 3 mm. RESULTS: A total of 72 (72%) of the study population had dimensions of equal to or greater than 3 mm throughout the entirety of the subchiasmatic corridor, making hypothalamic biopsy feasible through the ETSS route for these patients. CONCLUSION: Based on a radiological evaluation of the subchiasmatic corridor dimension in an Australian adult population, the majority of the population are suitable to undergo an endonasal transsphenoidal suprasellar subchiasmatic biopsy of the hypothalamus.

The utility of internal spinal marking for intraoperative localisation: A systematic review.

BACKGROUND: Incorrect level spinal surgery is an avoidable complication, with significant ramifications. Several pre-operative spinal marking techniques have been described to aid intraoperative localisation. METHODS: A systematic search of Ovid MEDLINE, and EMBASE was performed from inception to July 2022. All publications describing cases of internal spinal marking were included for further analysis. 22 articles describing 503 patients satisfied our eligibility criteria. RESULTS: A number of localisation techniques, including endovascular coiling (n = 16), fiducials (n = 177), dye (n = 109), needle/fixed wire (n = 199), cement (n = 4), and gadolinium tubes (n = 1) were described. The highest rates of technical success were observed with endovascular coiling, fiducials, cement and dye (100 %), and complication rates were lowest with endovascular coiling, fiducials and cement (0 %). CONCLUSIONS: Overall, internal spinal marking was effective and safe. When considering practicality and efficacy, fiducial marking appears the optimal technique, as it can be performed in the outpatient setting under local anaesthesia. This review demonstrates the need for more targeted investigation into localisation methods in spinal surgery.

Outcomes after inter-hospital transfer of intensive care patients with haemorrhagic stroke: a 5-year retrospective review.

BACKGROUND: Inter-hospital transfer (IHT) of intensive care patients is a limited resource. We assessed the outcomes of patients with haemorrhagic stroke requiring IHT and intensive care and aimed to identify early prognostic factors of poor neurological outcome. METHODS: We conducted a retrospective observational cohort study of patients admitted to a single tertiary intensive care unit (ICU) with haemorrhagic stroke after IHT between January 2014 and December 2018. Primary outcome was poor neurological outcome (modified Rankin Scale ≥4 at time of discharge from hospital or rehabilitation unit). Secondary outcomes were mortality rate, rate of intervention, rate of organ donation surgery (ODS) and potentially avoidable transfer (PAT). PAT was defined as transfer where the patient did not receive an intervention and had a poor neurological outcome. RESULTS: Ninety patients were included in this study, 48 with intracerebral haemorrhage (ICH) and 42 with subarachnoid haemorrhage (SAH). Fifty-one (56.7%) patients had a poor neurological outcome, including 30 (33%) who died. Factors significantly associated with poor neurological outcome included age > 80 years, lower presenting Glasgow Coma Score (GCS) and bilaterally fixed and dilated pupils. Stepwise logistic regression demonstrated history of hypertension as significantly associated with poor neurological outcome in patients with ICH (P = 0.021). Seven (7.8%) patients had ODS. Sixty-four (71.1%) patients received intervention and 20 (22.2%) transfers were potentially avoidable. CONCLUSIONS: Patients in this cohort are at high risk of poor neurological outcome. Prognostic factors identified in this study may help referring, retrieval and receiving clinicians to discuss futility prior to pursuing IHT.

The HACKD Score-Predicting Extent of Resection of Pituitary Macroadenomas Through an Endoscopic Endonasal Transsphenoidal Approach.

BACKGROUND: Predicting extent of resection before pituitary surgery is imperative for operative planning and patient counseling. In the era of endoscopic endonasal transsphenoidal surgery (EEA), a specific, reliable tool for predicting resection of macroadenomas would have widespread applications. OBJECTIVE: To identify factors that predict resection of pituitary macroadenomas through the EEA. METHODS: A prospectively maintained, multicenter database of 277 consecutive macroadenomas resected through the EEA was analyzed. Multivariate logistic regression identified predictors of gross total resection (GTR). A simple scoring system, the Hardy, Age, Clival, Knosp, Depth (HACKD) Score, was developed and tested. RESULTS: GTR was achieved in 82.3% (228/277) of cases. Older than 50 years (odds ratio [OR] 2.96, P = .01), clival extension (OR 5.87, P < .01), Hardy grade C or D suprasellar extension (OR 3.91, P = .01), Knosp grade 3 or 4 cavernous sinus invasion (OR 7.62, P < .01), and tumor depth >20 mm (OR 5.14, P < .01) were all associated with subtotal resection. The HACKD score, awarding 1 point each for Hardy grade C or D, and older than 50 years, and 2 points each for clival extension, Knosp grades 3 or 4, and tumor depth >20 mm, demonstrated excellent discriminative ability (AUROC 0.887, 95% CI: 0.839-0.934). The rate of GTR progressively decreased with a higher HACKD score. Rates of GTR were 95.8% (182/190) for low (HACKD ≤2), 59.5% (44/74) for moderate (HACKD 3-5), and 15.4% (2/13) for high (HACKD 6+) HACKD scores. CONCLUSION: The HACKD score is a simple and accurate tool based on the largest study analyzing predictors of GTR in pituitary macroadenomas operated through the EEA.

Quality of life and surgical outcomes in incidental pituitary adenomas undergoing endoscopic endonasal resection.

OBJECTIVE: Incidental, asymptomatic pituitary adenomas require nuanced, shared decision-making, which is limited by a poor understanding of their natural history and effects on quality of life (QOL). A greater understanding of the effects of surgery would inform evidence-based care. METHODS: A multicenter review of consecutive pituitary adenomas resected via an endoscopic endonasal approach (EEA) between late 2016 and mid-2021 was performed, with prospective, longitudinal QOL assessment (at 3 and 6 weeks and at 3, 6, and 12 months) postoperatively using the 35-item Anterior Skull Base Questionnaire. RESULTS: Of 366 adenomas resected during the study period, 52 (14.2%) were incidentally discovered, of which 51 (98.1%) were macroadenomas. Preoperative QOL in patients with these incidentalomas was better than in those with adenomas presenting with endocrinopathy (p < 0.01), visual failure (p = 0.02), or headache (p = 0.03). Surgery was performed due to visual field deficits (13.5%, n = 7); ophthalmoplegia (1.9%, n = 1); radiological compression or contact of the optic apparatus (63.5%, n = 33); functional status (growth hormone-secreting tumor) (5.8%, n = 3); and clinically significant growth (15.4%, n = 8). Surgical outcomes were excellent, with vision improved in 100% (7/7) and complete resection in 84.6% (44/52). There were 2 (3.8%) cases of new cortisol deficiency, 3 (5.8%) cases of transient postoperative diabetes insipidus, and 4 (7.7%) cases of postoperative hyponatremia. There were no perioperative complications and no cases of postoperative CSF leakage. QOL transiently decreased during the first 3 weeks after surgery, then improved to above baseline levels by 3 months (p = 0.03) and continued to improve throughout the first postoperative year (p = 0.03). All surgical indications demonstrated an overall mean improvement in QOL at 3 months. QOL benefits were not affected by age or tumor size. CONCLUSIONS: Resection of pituitary adenomas via the EEA provided a tangible benefit for patients within 3 months. Surgery via the EEA is safe, effective, and beneficial for patients with pituitary incidentalomas meeting accepted criteria for intervention.

Validation of the anterior skull base questionnaire 35 in endoscopic pituitary adenoma surgery.

Patient quality of life (QOL) is an important metric of surgical success. To guide therapeutic advances in pituitary adenoma surgery, a validated, comprehensive instrument to quantify QOL is required. We aim to evaluate the validity of the 35 item anterior skull base questionnaire (ASBQ-35) in patients undergoing pituitary adenoma surgery. A total of 168 patients undergoing endoscopic resection of pituitary adenomas underwent longitudinal QOL assessment using the ASBQ-35 and the 22-item Sinonasal Outcomes Test (SNOT-22) over the first postoperative year. Validity of the ASBQ-35 was assessed by internal consistency, test-retest reliability, responsiveness to clinical change, and concurrent validity with the SNOT-22. Internal consistency of the ASBQ-35 was excellent, with a Cronbach's alpha > 0.95 across all timepoints. Test-retest reliability between 3 and 6 months (ICC = 0.82, p < 0.001) and 6 months and 12 months (ICC = 0.78, p < 0.001) was robust. Concurrent validity with SNOT-22 was strong across all timepoints (absolute Pearson r ≥ 0.63, p < 0.001). Mean ASBQ-35 scores were significantly worse at 3 weeks compared to preoperative baseline (mean difference - 0.28, p < 0.01); however, by 12 months, scores had significantly improved (mean difference + 0.24, p < 0.01), indicating that the scale is responsive to clinical change. Each of the 6 domains of the ASBQ, and all 35 component questions, contributed to the discriminative of the ASBQ to measure QOL during the first postoperative year. The ASBQ-35 is a valid, comprehensive tool for assessing QOL after endoscopic pituitary adenoma surgery. Each component of the ASBQ-35 contributed to the overall assessment of QOL during the first postoperative year.

Postoperative fluid restriction to prevent hyponatremia after transsphenoidal pituitary surgery: An updated meta-analysis and critique.

BACKGROUND: Hyponatremia is a common and potentially dangerous complication of transsphenoidal surgery. Prophylactic postoperative fluid restriction has been trialled as a method to reduce the incidence of postoperative hyponatremia. METHODS: A systematic review of the literature was performed in accordance with the PRISMA statement. Risk of bias was assessed using the MINORS criteria. Meta-analysis was performed using the random-effects model. RESULTS: A total of 6 retrospective cohort studies were available for analysis. Fluid restriction was commonly between 1000 and 1500 ml/day and limited to the first postoperative week. Overall, the rate postoperative hyponatremia was fourfold less in the fluid restricted cohorts (3.4 % vs 11.2 %, OR 0.24 (95 %CI 0.15-0.38), p < 0.01). There was no difference in readmission rates (1.4 % vs 3.9 %, OR 0.32 (95 %CI 0.09-1.13), p = 0.08) or postoperative diabetes insipidus (14.5 % vs 18.6 %, OR 0.82 (95 %CI 0.50-1.36), p = 0.45) between fluid restricted and control cohorts. CONCLUSION: Prophylactic postoperative fluid restriction is a cheap, easily implemented intervention that appears to reduce the rate of postoperative hyponatremia, but not necessarily re-admission rates. Whether these prevented cases of hyponatremia are clinically significant remains to be demonstrated.

Relationship between herniated intervertebral disc fragment weight and pain in lumbar microdiscectomy patients.

OBJECTIVE: The relationship between lumbar disc herniation (LDH) size and the severity of preoperative pain and its impact on postoperative recovery is incompletely understood. This study was conducted to investigate the association between herniated disc fragment weight and pain before and after microdiscectomy. METHODS: A consecutive series of patients from an ongoing randomised controlled trial (ACTRN12616001360404) were included in this study. Included patients were aged between 18 and 75, had a clinical diagnosis of radiculopathy, and MRI evidence of a concordant single-level lumbar disc herniation. All patients underwent standard microdiscectomy without aggressive discectomy or curettage of the endplates. Disc fragment weight was measured intraoperatively. RESULTS: A total of 122 patients with a mean age of 49.5 ± 12.8 years, were included. The median weight of disc fragment was 0.545 g (95% CI 0.364 - 0.654 g). There was no relationship between disc weight and the duration of symptoms (p = 0.409) severity of preoperative leg pain (p = 0.070) or preoperative back pain (p = 0.884). Disc fragment weight was demonstrated to have no correlation with clinically significant postoperative leg pain improvement (p = 0.535) or back pain (p = 0.991). Additional LDH factors, including radiological percentage of canal compromise (p = 0.714), herniation classification (p = 0.462), and vertebral level (p = 0.788) were also shown to have no effect on leg pain outcomes. CONCLUSIONS: Disc fragment weight had no effect on the severity of pain at presentation or after microdiscectomy. Patients benefit from surgery equally, regardless of the size of LDH.

Surgical outcomes and longitudinal quality of life after endoscopic endonasal surgery for anterior skull base meningioma.

OBJECTIVE: The objective of this study was to establish the effect of endoscopic endonasal surgery on longitudinal quality of life (QOL) in patients with anterior skull base meningioma. METHODS: A prospectively collected cohort of consecutively operated anterior skull base meningiomas was analyzed. All cases were performed using the endoscopic endonasal approach (EEA). Sinonasal-specific and overall QOL were measured using the 22-Item Sinonasal Outcome Test and the Anterior Skull Base Questionnaire longitudinally (at 3 weeks, 6 weeks, and 3, 6, and 12 months) across the first postoperative year. The relationship between surgical and QOL outcomes to clinical and radiological characteristics was analyzed using multivariate regression. RESULTS: Fifty cases were available, with a mean age of 61.5 years and female predominance (74.0%). Visual dysfunction and headache were the most common presenting symptoms, and tumors commonly took origin from the planum (46.0%), tuberculum (44.0%), and olfactory groove (24.0%). Median tumor volume was 4.6 cm3. Visual improvement was noted in 73.1% of cases with preoperative field deficits, while nonimprovement was associated with greater tumor height (p = 0.04). Gross-total resection was not possible in patients with 360° vessel encasement and high-grade cavernous sinus extension with ophthalmoplegia. Postoperative diabetes insipidus was observed only in cases with suprasellar extension. Sinonasal-specific QOL worsened transiently after surgery but returned to baseline levels after 3 weeks. Olfaction and taste scores returned to preoperative baseline scores within the year. Overall QOL at presentation was worse in those with larger tumors (p = 0.04) and visual failure (p = 0.04) and better in those presenting with headache (p = 0.04). Transient worsening of QOL was seen in the first 3 weeks, which returned to baseline by 6 weeks, and then improved to above preoperative levels at 6 months and beyond. Worse QOL at baseline (p = 0.01) and visual improvement (p = 0.01) predicted QOL improvement after surgery. CONCLUSIONS: Longitudinal QOL in anterior skull base meningioma has been examined for the first time. Endoscopic endonasal surgery improves overall QOL after a transient 3-week worsening due to the sinonasal morbidity of the approach. Visual function is intimately tied to QOL, with worse vision associated with worse preoperative QOL, and QOL improving in parallel with visual restoration after surgery. The EEA is associated with better visual outcomes and should be the preferred approach in accessible tumors.

Surgical outcomes and quality of life in Rathke's cleft cysts undergoing endoscopic transsphenoidal resection: a multicentre study and systematic review of the literature.

OBJECTIVE: To establish the effect of endoscopic endonasal surgery (EES) on quality-of-life (QoL) in symptomatic Rathke cleft cyst (RCC). METHODS: Analysis of 38 patients with RCC treated by EES, with regular overall (ASBQ-35) and sinonasal-specific (SNOT-22) QoL assessment during the first postoperative year. A systematic literature review of large case series was performed with pooled analysis. RESULTS: In our series, mean age was 53.6 years with a female predominance (73.7%). Larger cysts were seen in males (p < 0.01), those with hypogonadism (p = 0.04), and visual dysfunction (p = 0.04). Complete normalisation of vision was seen in 83.3%. Persistence of visual dysfunction postoperatively was associated with diabetes (p = 0.005), hypertension (p = 0.02), suprasellar only location (p = 0.001), and monocular field cut (p = 0.02). Surgery did not significantly effect hormonal function. Sinonasal QoL transiently worsened after surgery, resolving within 3 weeks. A parallel transient worsening of overall QoL normalised by 6 weeks, and remained at preoperative baseline thereafter. These results were comparable to the literature, where 76.4% demonstrated improvement of vision and 13.1% had recurrence after treatment. There was no significant difference in outcomes between EES and microscopic approaches. CONCLUSIONS: We report longitudinal QoL outcomes in RCC for the first time. Vision commonly improves with surgery, but endocrinopathy is likely to persist. Microvascular risk-factors may compromise visual improvement. Surgery causes a transient worsening of sinonasal symptoms that resolves within 3-6 weeks, but patients may not experience significant improvement in QoL within the first postoperative year.

Learning Curve for Robot-Assisted Percutaneous Pedicle Screw Placement in Thoracolumbar Surgery.

STUDY DESIGN: Retrospective review of an initial cohort of consecutive patients undergoing robot-assisted pedicle screw placement. PURPOSE: We aimed to evaluate the learning curve, if any, of this new technology over the course of our experience. OVERVIEW OF LITERATURE: Percutaneous pedicle screws have specific advantages over open freehand screws. However, they require intraoperative imaging for their placement (e.g., fluoroscopy and navigation) and require increased surgeon training and skill with the learning curve estimated at approximately 20-30 cases. To our knowledge, this is the first study that measures the learning curve of robot-guided purely percutaneous pedicle screw placement with comprehensive objective postoperative computed tomography (CT) scoring, time per screw placement, and fluoroscopy time. METHODS: We included the first 80 consecutive patients undergoing robot-assisted spinal surgery at Melbourne Private Hospital. Data were collected for pedicle screw placement accuracy, placement time, fluoroscopy time, and revision rate. Patient demographic and relevant perioperative and procedural data were also collected. The patients were divided equally into four sub-groups as per their chronological date of surgery to evaluate how the learning curve affected screw placement outcomes. RESULTS: Total 80 patients were included; 73 (91%) had complete data and postoperative CT imaging that could help assess that placement of 352 thoracolumbar pedicle screws. The rate of clinically acceptable screw placement was high (96.6%, 95.4%, 95.6%, and 90.7%, in groups 1 to 4, respectively, p=0.314) over time. The median time per screw was 7.0 minutes (6.5, 7.0, 6.0, and 6.0 minutes in groups 1 to 4, respectively, p=0.605). Intraoperative revision occurred in only 1 of the 352 screws (0.3%). CONCLUSIONS: We found that robot-assisted screw placement had high accuracy, low placement time, low fluoroscopy time, and a low complication rate. However, there were no significant differences in these parameters at the initial experience and the practiced, experience placement (after approximately 1 year), indicating that robot-assisted pedicle screw placement has a very short (almost no) learning curve.