How to Reduce the Risk of Mechanical Failures in Adult Deformity Surgery: Comparing GAP Score and Roussouly Type Restoration

Global Spine Journal 2025, Vol. 0(0) 1–15

DOI: 10.1177/21925682251328285

This study investigates the predictors of mechanical failure in adult spinal deformity surgery, highlighting the significance of the GAP score and Roussouly type restoration in minimizing complications. A proper post-operative GAP Score and spinal alignment restoration are crucial for reducing mechanical failure rates.

Study Design and Methods

• Retrospective cohort study with a 5-year follow-up on adult spinal deformity cases.

• Inclusion criteria: Patients over 18, with at least 4 vertebrae fused.

• Data collected: Demographic, surgical, spinopelvic parameters, and complications.

Key Findings

• Mechanical Complications: Revision surgery rate was 40.6%.

• Higher post-operative GAP scores linked to increased junctional failure risk.

• Roussouly Type Restoration: Failure to restore original type increases mechanical failure risk.

Predictive Analysis

• GAP Score and Roussouly Type are top predictors for mechanical failure.

• Gradient Boosting model showed high predictive accuracy (ASE 0.073).

• Kaplan-Meier Analysis: Higher GAP scores linked to earlier junctional failures.

Recommendations

• Surgical Planning: Restore original Roussouly type and achieve proper lumbar lordosis.

• Avoid Pelvic Retroversion: Ensure proper global balance.

Statistical Analysis

• Logistic regression confirmed GAP score and Roussouly type as significant predictors.

• ROC Curves: Moderate association between GAP score and revision surgery need.

Limitations

• Retrospective design with potential selection bias.

• Asymmetrical sample size of GAP score groups.

Level of Evidence

3 retrospective cohort study

Older meningioma patients: a retrospective population‐based study of risk factors for morbidity and mortality after neurosurgery

Acta Neurochirurgica (2022) 164:2987–2997

Meningioma is the most common primary CNS tumour. Most meningiomas are benign, and most patients are 65 years or older. Surgery is usually the primary treatment option. Most prior studies on early surgical outcomes in older patients with meningioma are small, and there is a lack of larger population-based studies to guide clinical decision-making. We aimed to explore the risks for perioperative mortality and morbidity in older patients with meningioma and to investigate changes in surgical incidence over time.

Methods In this retrospective population-based study on patients in Sweden, 65 years or older with surgery 1999–2017 for meningioma, we used data from the Swedish Brain Tumour Registry. We analysed factors contributing to perioperative mor- tality and morbidity and used official demographic data to calculate yearly incidence of surgical procedures for meningioma.

Results Thefinal study cohort included 1676 patients with a 3.1% perioperative mortality and a 37.6% perioperative morbidity. In multivariate analysis, higher age showed a statistically significant association with higher perioperative mortality, whereas larger tumour size and having preoperative symptoms were associated with higher perioperative morbidity. A numerical increased rate of surgical interventions after 2012 was observed, without evidence of worsening short-term surgical outcomes.

Conclusions Higher mortality with increased age and higher morbidity risk in larger and/or symptomatic tumours imply a possible benefit from considering surgery in selected older patients with a growing meningioma before the development of tumour-related symptoms. This study further underlines the need for a standardized method of reporting and classifying complications from neurosurgery.

Clival chordomas: considerations after 16 years of endoscopic endonasal surgery

J Neurosurg 128:329–338, 2018

In the past decade, the role of the endoscopic endonasal approach (EEA) has relevantly evolved for skull base tumors. In this study, the authors review their surgical experience with using an EEA in the treatment of clival chordomas, which are deep and infiltrative skull base lesions, and they highlight the advantages and limitations of this ventral approach.

METHODS All consecutive cases of chordoma treated with an EEA between 1998 and 2015 at a single institution are included in this study. Preoperative assessment consisted of neuroimaging (MRI and CT with angiography sequences) and endocrinological, neurological, and ophthalmological evaluations, which were repeated 3 months after surgery and annually thereafter. Postoperative adjuvant therapies were considered.

RESULTS Sixty-five patients (male/female ratio 1:0.9) were included in this study. The median age was 48 years (range 9–80 years). Gross-total resection (GTR) was achieved in 47 cases (58.7%). On univariate analysis, primary procedures (p = 0.001), location in the superior or middle third of the clivus (p = 0.043), extradural location (p = 0.035), and histology of conventional chordomas (p = 0.013) were associated with a higher rate of GTR. The complication rate was 15.1%, and there were no perioperative deaths. Most complications did not result in permanent sequelae and included 2 CSF leaks (2.5%), 5 transient cranial nerve VI palsies (6.2%), and 2 internal carotid artery injuries (2.5%), which were treated with coil occlusion of the internal carotid artery without neurological deficits. Three patients (3.8%) presented with complications resulting in permanent neurological deficits due to a postoperative hematoma (1.2%) causing a hemiparesis, and 2 permanent ophthalmoplegias (2.5%). Seventeen patients (26.2%) have died of tumor progression over the course of follow-up (median 52 months, range 7–159 months). Based on Kaplan-Meier analysis, the survival rate was 77% at 5 years and 57% at 10 years. On multivariate analysis, the extent of tumor removal (p = 0.001) and the absence of previous treatments (p = 0.001) proved to be correlated with a longer survival rate.

CONCLUSIONS The EEA was associated with a high rate of tumor removal and symptom control, with low morbidity and preservation of a good quality of life. These results allow for a satisfactory overall survival rate, particularly after GTR and for primary surgery. Considering these results, the authors believe that an EEA can be a helpful tool in chordoma surgery, achieving a good balance between as much tumor removal as possible and the preservation of an acceptable patient quality of life.

Routine early CT scanning after craniotomy: is it effective for the early detection of postoperative intracranial hematoma?

postoperative intracranial hematoma

Acta Neurochir (2016) 158:1447–1452

Postoperative intracranial hematoma (POIH) is a frequent sequela secondary to cranial surgery. The role of routine early postoperative computed tomography (CT) scanning in the detection of POIH remains controversial. The study was aimed at analyzing the effect of routine early CT scanning after craniotomy for the early detection of POIH.

Methods Routine early postoperative CT scanning was performed at our institute, and a retrospective study was conducted to analyze the data. POIH was defined as an intra- cranial hematoma requiring surgical management.

Results A total of 1,148 patients undergoing craniotomy were included in this study; 28 of these patients developed POIH. The majority of POIH cases (15/28, 54 %) were detected during the first 6 h following craniotomy. A routine CT scan was per- formed on all included patients but two; however, CT scans detected only 16 POIH cases. During the first 6 h, the rate at which CT scans detected POIH was 1.9 % (15/786); subse- quently, the rate decreased to only 0.3 % (1/360; p<0.05, compared with the rate during the first 6h). Among patients without clinical manifestations, the rate at which the routine post-craniotomy CT scan detected POIH was only 0.7 % (5/721) (p<0.05, compared with the incidence of POIH). Finally, among high-risk POIH patients, the POIH-positive rate of routine CT scanning was elevated.

Conclusions It appears that routine early CT scan is ineffective for the detection of POIH in patients undergoing craniotomy. However, if the strategy for routine scanning can be improved, its effect may be beneficial.

Impact of therapeutic regimen and clinical presentation on overall survival in CNS lymphoma

Primary LymphomaActa Neurochir (2014) 156:355–365

The authors present a retrospective analysis of 45 patients who underwent treatment of CNS lymphoma (both primary and secondary) at a single institution between 2005 and 2012. Methods This study involves 21 female and 24 male patients with a mean age of 59.2 years. All medical records and pathology reports were reviewed for each patient. Univariate and multivariate analyses of overall survival were performed.

Results Presentation with altered mental status was a significant risk factor for worse overall survival. An HIV infection, deep lesion location, and age over 60 did not impact survival. A survival benefit was demonstrated with the use of systemic therapy, specifically rituximab, and radiation. The CNS Lymphoma Score was derived from this cohort, which proved a powerful predictive tool for overall survival. The surgical complication rate in this series was 17.8 %.

Conclusions This study highlights the prognostic importance of presentingmental status on outcomes in CNS lymphoma and demonstrates a summative benefit of rituximab and whole brain radiation therapy. Considering these factors together provides an easily applicable andmeaningful stratification for this patient population. The surgical complication rate in this patient population is not negligible. The high percentage of wound-related surgical complications suggests the need for a waiting period between surgery and initiation of chemotherapy to allow for wound healing.

Hardware-related infections after deep brain stimulation surgery: review of incidence, severity and management in 212 single-center procedures in the first year after implantation

Acta Neurochir (2011) 153:2337–2341. DOI 10.1007/s00701-011-1130-2

Device-related infection is a common occurrence after deep brain stimulation (DBS) surgery, and may result in additional interventions and a loss of efficacy of therapy. This retrospective review aimed to evaluate the incidence, severity and management of device-related infections in 212 DBS procedures performed in our institute.

Methods Data on 106 patients, in whom 212 DBS procedures were performed between 2001 and 2011 at our institute by a single neurosurgeon (M.P.), were reviewed to assess the incidence, severity, management and clinical characteristics of infections in the first year after the implantation of a DBS system.

Results Infections occurred in 8.5% of patients and 4.2% of procedures. Of the nine infections, eight involved the neurostimulator and extensions, and one the whole system. The infections occurred 30.7 days after implantation: 7 within 30 days and 2 within 6 months. Infected and uninfected patients were comparable in terms of age, sex, indication for DBS implantation and neurostimulator location. In eight cases, the system components involved were removed and re-implanted after 3 months, while in one case the complete hardware was removed and not re-implanted.

Conclusion The overall incidence of postoperative infections after DBS system implantation was 4.2%; this rate decreased over time. All infections required further surgery. Correct and timely management of partial infections may result in successful salvage of part of the system.

Transgressing the Ventricular Wall During Subthalamic Deep Brain Stimulation Surgery for Parkinson Disease Increases the Risk of Adverse Neurological Sequelae

Neurosurgery 69:294–300, 2011 DOI: 10.1227/NEU.0b013e318214abda

Deep brain stimulation (DBS) at the subthalamic nucleus (STN) is an effective treatment for the motor manifestations of advanced medically refractory Parkinson disease. Because of the medial location of the target, surgical trajectories to the STN may violate the ipsilateral lateral ventricle.

OBJECTIVE: To determine whether violating the ventricle during STN DBS surgery is associated with postoperative confusion.

METHODS: A retrospective chart review of all STN implantation procedures for Parkinson disease performed by 1 surgeon between January 2005 and September 2008 was performed. Postoperative magnetic resonance imaging was performed in all cases, and each scan was reviewed for evidence of ventricular wall violation. All charts were reviewed for postoperative confusion and/or increased length of hospital stay.

RESULTS: A total of 145 leads were implanted in 81 patients over 102 admissions. Fortythree patients underwent contemporaneous bilateral lead implantation; 23 underwent unilateral implantation; and 18 underwent staged bilateral implantation. The cases of 8 patients were complicated by postoperative confusion and increased length of stay. Sixteen magnetic resonance imaging scans demonstrated evidence of ventricular wall violation including all 8 patients with postoperative confusion. The relative risk of having postoperative confusion after traversing the ventricle is 87 (P , .001).

CONCLUSION: Violating the ventricular system during STN DBS surgery correlated significantly with postoperative altered mental status and subsequent increased length of hospital stay. This finding may explain why cognitive complications are observed more frequently in Parkinson disease patients undergoing DBS at the STN compared with the internal globus pallidus.