Development and Validation of a Clinical Prediction Model for Venous Thromboembolism Following Neurosurgery: A 6-Year, Multicenter, Retrospective and Prospective Diagnostic Cohort Study

BACKGROUND

Based on the literature and data on its clinical trials, the incidence of venous thromboembolism (VTE) in patients undergoing neurosurgery has been 3.0%~26%. We used advanced machine learning techniques and statistical methods to provide a clinical prediction model for VTE after neurosurgery.

METHODS

All patients (n = 5867) who underwent neurosurgery from the development and retrospective internal validation cohorts were obtained from May 2017 to April 2022 at the Department of Neurosurgery at the Sanbo Brain Hospital. The clinical and biomarker variables were divided into pre-, intra-, and postoperative. A univariate logistic regression (LR) was applied to explore the 67 candidate predictors with VTE. We used a multivariable logistic regression (MLR) to select all significant MLR variables of MLR to build the clinical risk prediction model. We used a random forest to calculate the importance of significant variables of MLR. In addition, we conducted prospective internal (n = 490) and external validation (n = 2301) for the model.

RESULTS

Eight variables were selected for inclusion in the final clinical prediction model: D-dimer before surgery, activated partial thromboplastin time before neurosurgery, age, craniopharyngioma, duration of operation, disturbance of consciousness on the second day after surgery and high dose of mannitol, and highest D-dimer within 72 h after surgery. The area under the curve (AUC) values for the development, retrospective internal validation, and prospective internal validation cohorts were 0.78, 0.77, and 0.79, respectively. The external validation set had the highest AUC value of 0.85.

CONCLUSIONS

This validated clinical prediction model, including eight clinical factors and biomarkers, predicted the risk of VTE following neurosurgery. Looking forward to further research exploring the standardization of clinical decision-making for primary VTE prevention based on this model.

Same-day versus staged revascularization of bilateral moyamoya arteriopathy in pediatric patients

PURPOSE

To compare the outcomes of conducting left and right hemisphere surgical revascularization on the same day versus different days for bilateral pediatric moyamoya arteriopathy patients.

METHODS

We retrospectively analyzed mortality, stroke, and transient neurologic event (TNE) rates in North American bilateral pediatric moyamoya arteriopathy patients who underwent bilateral cerebral revascularization.

RESULTS

A total of 38 pediatric (≤ 18 years old) patients at our institution underwent bilateral cerebral revascularization for moyamoya arteriopathy. Of these patients, 24 (63.2%) had both operations on the same day and 14 (36.8%) had the two operations on different days. The average length of stay for patients who underwent same-day bilateral revascularization was 6.9 ± 2.0 days and the average length of stay for each operation for patients who underwent staged bilateral revascularization was 4.5 ± 1.4 days, p = 0.001. While there were 7 (14.6%) postoperative strokes in patients who had both hemispheres revascularized on the same day, 0 (0%) strokes occurred in hemispheres after they had been operated on in the staged cohort, p = 0.042. Additionally, the postoperative stroke-free survival time in the ipsilateral hemisphere and TNE-free survival time were significantly longer in patients in the staged revascularization cohort.

CONCLUSION

Same-day bilateral revascularization was associated with longer length of stay per operation, higher rate of ipsilateral stroke, and shorter postoperative TNE-free and stroke-free survival time in the revascularized hemisphere.

A nomogram model to predict the acute venous thromboembolism risk after surgery in patients with glioma

INTRODUCTION

Postoperative venous thromboembolism (VTE) is a common complication for glioma patients, with an incidence rate of about 20 %. The purpose of this study was to explore the risk factors of acute VTE after glioma surgery, which may provide an essential reference for clinical guidance on the prevention of acute VTE.

MATERIALS AND METHODS

A total of 435 patients who underwent glioma surgery from 2012 to 2021 were included in this study. Duplex ultrasonography was performed routinely 3-5 days after the surgery to define VTE. Univariate and multivariate logistic regression analyses were performed to explore the independent predictor of acute VTE after glioma surgery and use these selected risk factors to construct and validate a nomogram.

RESULTS

Several risk factors for predicting acute VTE after glioma surgery were identified and used to build the nomogram: age, operation time, systemic immune-inflammation index (SII), hypertension, and diabetes mellitus. The area under the curve of the nomogram was 0.834, indicating good discrimination. Hosmer-Lemeshow of the calibration curve was 3.05 (P = 0.98), showing a high degree of agreement between the prediction and actual outcome. Decision curve analysis indicated that the nomogram model was helpful when the incidence of VTE was 5-80 %.

CONCLUSIONS

A nomogram to predict acute VTE after glioma surgery was constructed and validated. Clinicians can use this predictive model to achieve risk assessment and take different treatment measures to prevent acute postoperative VTE and improve patients' quality of life effectively.

Work relative value units and perioperative outcomes in patients undergoing brain tumor surgery

The work relative value unit (wRVU) is a commonly cited surrogate for surgical complexity; however, it is highly susceptible to subjective interpretation and external forces. Our objective was to evaluate whether wRVU is associated with perioperative outcomes, including complications, after brain tumor surgery. The 2006-2014 American College of Surgeons National Surgical Quality Improvement Program database was queried to identify patients ≥ 18 years who underwent brain tumor resection. Patients were categorized into approximate quintiles based on total wRVU. The relationship between wRVU and several perioperative outcomes was assessed with univariate and multivariate analyses. Subgroup analyses were performed using a Current Procedural Terminology code common to all wRVU groups. The 16,884 patients were categorized into wRVU ranges 0-30.83 (4664 patients), 30.84-34.58 (2548 patients), 34.59-38.04 (3147 patients), 38.05-45.38 (3173 patients), and ≥ 45.39 (3352 patients). In multivariate logistic regression analysis, increasing wRVU did not predict more 30-day postoperative complications, except respiratory complications and need for blood transfusion. Linear regression analysis showed that wRVU was poorly correlated with operative duration and length of stay. On multivariate analysis of the craniectomy subgroup, wRVU was not associated with overall or respiratory complications. The highest wRVU group was still associated with greater risk of requiring blood transfusion (OR 3.01, p < 0.001). Increasing wRVU generally did not correlate with 30 days postoperative complications in patients undergoing any surgery for brain tumor resection; however, the highest wRVU groups may be associated with greater risk of respiratory complications and need for transfusion. These finding suggests that wRVU may be a poor surrogate for case complexity.

[Incidence and risk factors of venous thromboembolic events after resection of various brain tumors]

Venous thromboembolic events (VTE) can significantly complicate postoperative period in neurosurgical patients. It is known that patients with brain tumors are especially susceptible to VTE.

OBJECTIVE

To determine the incidence and risk factors of VTE in patients with various brain tumors.

MATERIAL AND METHODS

All patients with brain tumors underwent surgery in 2019 (n=610). They were divided into the groups depending on tumor type: sellar region, intracerebral, extracerebral neoplasms and metastases. All patients underwent screening and prevention of VTE in accordance with the protocol accepted in the hospital. We analyzed the incidence of VTE in each group and significance of various risk factors.

RESULTS

Overall incidence of VTE was 14.9% (91 cases). Deep vein thrombosis (DVT) was the most common - 85 cases (93.4%). Less common events were DVT combined with pulmonary embolism (PE) (n=5, 5.5%) and PE alone (n=1; 1.1%). PE caused death in 2 cases (0.3%). In patients with sellar tumors, incidence was 21.7% [13.4%; 29.35%], among intracerebral tumors - 13.8% [9.04%; 18.62%], extracerebral neoplasms - 15.4% [11.02%; 19.69%], metastases - 7.9% [1.32%; 11.84%]. Univariate and multivariate analysis revealed some risk factors of VTEs such as gender, age, surgery time, length of ICU-stay over 12 hours, body mass index >30 kg/m². Moreover, risk factors have different significance in patients with different types of tumors.

CONCLUSION

In this study, we found a high incidence of VTE among patients with brain tumors. Incidence and risk factors of VTE depend on the type of tumor.

Homologous amniotic membrane as a dural substitute in decompressive craniectomies

INTRODUCTION

A dura mater substitute in decompressive craniectomies must protect the brain while providing a dissection plane between the cortex and myocutaneous layer. The human amniotic membrane (AM) has anti-inflammatory, wound healing, and differentiation properties. We tested AM properties as a dural substitute by comparing the outcomes to biological ones.

METHODS

We prospectively collected data on 25 patients who randomly underwent decompressive craniectomy with lyophilized AM patches and 25 in which biological substitutes were utilized between 2015 and 2019. The AM was laid with the epithelial side facing the brain because of the anti-adhesive proprieties, while the chorion facing the myocutaneous flap. We collected data on demographics, neurological status, comorbidities, and surgical outcomes. Additionally, we created a score - dura mimicking score- and reviewed postoperative imaging and pathological specimens.

RESULTS

The majority (96%) of AM grafts were integrated into native dura. Thirteen patients scored as excellent and 11 good on our "dura mimicking score", showing tissue integration ability but no cerebral cortex adhesion. The histopathological analysis showed that AM had thick plates of dense fibrous tissue with small reactive vessels, reactive fibroblasts, and lymphocytes infiltrate. The AM group's first outcomes were not different from the biological substitute patients but higher integration rate to the dura and less adhesion to the myocutaneous flap in AM patients.

CONCLUSIONS

We documented the anti-adhesive, protective, and integrative properties of AM dural substitute patches in patients who underwent decompressive craniectomies, comparing the intraoperative differences and postoperative outcomes to biological dural substitutes.

Risk factors for venous thromboembolism and evaluation of the modified Caprini score in patients undergoing lung resection

Background

There is a high incidence of venous thromboembolism (VTE) after lung resection, so it is necessary to identify the risk factors for VTE in these patients. It is also important to evaluate whether the modified Caprini score can accurately assess the risk of VTE in patients after lung resection.

Methods

This retrospective study included 437 patients undergoing lung resection between July 2016 and December 2017. All patients underwent lower extremities ultrasound before and after operation to determine the presence of the newly diagnosed VTE.

Results

Forty-seven (10.8%) of the 437 patients were diagnosed with VTE after lung surgery. Multivariate logistic regression analysis showed that age (OR, 2.04; 95% CI, 1.40-2.99), duration of operation (OR, 1.51; 95% CI, 1.08-2.12), lymphocyte count (OR, 0.28; 95% CI, 0.11-0.69), and D-dimer concentration (OR, 1.55; 95% CI, 1.22-1.97) were significantly associated with VTE in lung resection patients. The cut-off values for lymphocyte count and D-dimer concentration determined using receiver operating characteristic (ROC) curve were 1.15×10⁹/L and 1.37 µg/mL respectively. The modified Caprini score divided the patients into three groups: low risk (0-4 points), moderate risk (5-8 points) and high risk (≥9 points), and the incidence of VTE was 12.3% (37/300), 7.5% (10/133) and 0% (0/4), respectively (P>0.05).

Conclusions

In this study, we identified four independent factors for VTE after lung resection patients: age, duration of operation, lymphocyte count, and D-dimer. According to the modified Caprini score, there were fewer patients in the high-risk group, and the incidence of VTE not increased with the increase of risk. Better evaluation of operation time and D-dimer may help the modified Caprini score to better assess VTE risk in these patients.

Postoperative delayed trapped temporal horn in patients with lateral ventricular trigone meningioma: Risk factors, surgical management, and literature review

OBJECT

To assess the risk factors for and surgical treatment of delayed trapped temporal horn (dTTH) in patients who had undergone removal of lateral ventricular trigone meningioma.

METHOD

Patients with lateral ventricular trigone meningioma treated at our institution from 2011 to 2015 were identified. Predictors for dTTH were determined using logistic regression. Literature review and pooled analysis were also conducted to evaluate the comparative effectiveness of surgical treatment for dTTH.

RESULTS

A total of 110 cases were included in the analysis. Thirteen (11.8%) cases developed dTTH following surgery. Multivariable logistic regression demonstrated an association of longer operative duration with higher incidence of dTTH (OR, 1.34; 95% CI, 1.00-1.80; p = 0.049). As surgical duration prolonged from less than 3 hours to 5 hours or more, the incidence of dTTH increased in a consistent, linear fashion from 7.7% to 13.9% (p = 0.03). Six cases (46.2%, 6/13) of dTTH underwent surgical treatment for their life-threatening symptoms. Seven studies including 13 cases of dTTH in the literature were identified. Literature data, including the current series, revealed a total of 24 procedures were performed in 19 cases. Endoscopic fenestration trended toward fewer complications than shunt (7.7% vs 25.0%, p = 0.530). There were no significant differences in failure rates between the two groups (23.1% vs 25.0%, p = 1.000).

CONCLUSION

Patients with prolonged operative duration may be at higher risk of dTTH. Endoscopic fenestration is considered in preference to shunt placement, since it possesses equivalent success rates with fewer complications and avoids the need for a permanent implant.

Quality of British and American Nationwide Quality of Care and Patient Safety Benchmarking Programs: Case Neurosurgery

BACKGROUND

Multiple nationwide outcome registries are utilized for quality benchmarking between institutions and individual surgeons.

OBJECTIVE

To evaluate whether nationwide quality of care programs in the United Kingdom and United States can measure differences in neurosurgical quality.

METHODS

This prospective observational study comprised 418 consecutive adult patients undergoing elective craniotomy at Helsinki University Hospital between December 7, 2011 and December 31, 2012.We recorded outcome event rates and categorized them according to British Neurosurgical National Audit Programme (NNAP), American National Surgical Quality Improvement Program (NSQIP), and American National Neurosurgery Quality and Outcomes Database (N2QOD) to assess the applicability of these programs for quality benchmarking and estimated sample sizes required for reliable quality comparisons.

RESULTS

The rate of in-hospital major and minor morbidity was 18.7% and 38.0%, respectively, and 30-d mortality rate was 2.4%. The NSQIP criteria identified 96.2% of major but only 38.4% of minor complications. N2QOD performed better, but almost one-fourth (23.2%) of all patients with adverse outcomes, mostly minor, went unnoticed. For NNAP, a sample size of over 4200 patients per surgeon is required to detect a 50.0% increase in mortality rates between surgeons. The sample size required for reliable comparisons between the rates of complications exceeds 600 patients per center per year.

CONCLUSION

The implemented benchmarking programs in the United Kingdom and United States fail to identify a considerable number of complications in a high-volume center. Health care policy makers should be cautious as outcome comparisons between most centers and individual surgeons are questionable if based on the programs.

Reporting Methodology of Neurosurgical Studies Utilizing the American College of Surgeons-National Surgical Quality Improvement Program Database: A Systematic Review and Critical Appraisal

BACKGROUND

Use of large databases such as the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) has become increasingly common in neurosurgical research.

OBJECTIVE

To perform a critical appraisal and evaluation of the methodological reporting for studies in neurosurgical literature that utilize the ACS-NSQIP database.

METHODS

We queried Ovid MEDLINE, EMBASE, and PubMed databases for all neurosurgical studies utilizing the ACS-NSQIP. We assessed each study according to number of criteria fulfilled with respect to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement, REporting of studies Conducted using Observational Routinely-collected Health Data (RECORD) Statement, and Journal of American Medical Association–Surgical Section (JAMA-Surgery) Checklist. A separate analysis was conducted among papers published in core and noncore journals in neurosurgery according to Bradford's law.

RESULTS

A total of 117 studies were included. Median (interquartile range [IQR]) scores for number of fulfilled criteria for STROBE Statement, RECORD Statement, and JAMA-Surgery Checklist were 20 (IQR:19-21), 9 (IQR:8-9), and 6 (IQR:5-6), respectively. For STROBE Statement, RECORD Statement, and JAMA-Surgery Checklist, item 9 (potential sources of bias), item 13 (supplemental information), and item 9 (missing data/sensitivity analysis) had the highest number of studies with no fulfillment among all studies (56, 68, 50%), respectively. When comparing core journals vs noncore journals, no significant difference was found (STROBE, P = .94; RECORD, P = .24; JAMA-Surgery checklist, P = .60).

CONCLUSION

While we observed an overall satisfactory reporting of methodology, most studies lacked mention of potential sources of bias, data cleaning methods, supplemental information, and external validity. Given the pervasive role of national databases and registries for research and health care policy, the surgical community needs to ensure the credibility and quality of such studies that ultimately aim to improve the value of surgical care delivery to patients.

Venous thromboembolism following inpatient pediatric surgery: Analysis of 153,220 patients

PURPOSE

To evaluate venous thromboembolism (VTE) rates and risk factors following inpatient pediatric surgery.

METHODS

153,220 inpatient pediatric surgical patients were selected from the 2012-2015 NSQIP-P database. Demographic and perioperative variables were documented. Primary outcome was VTE requiring treatment within 30 postoperative days. Secondary outcomes included length of stay (LOS) and 30-day mortality. Prediction models were generated using logistic regression. Mortality and time to VTE were assessed using Kaplan-Meier survival analysis.

RESULTS

305 patients (0.20%) developed 296 venous thromboses and 12 pulmonary emboli (3 cooccurrences). Median time to VTE was 9 days. Most VTEs (81%) occurred predischarge. Subspecialties with highest VTE rates were cardiothoracic (0.72%) and general surgery (0.28%). No differences were seen for elective vs. urgent/emergent procedures (p = 0.106). All-cause mortality VTE patients was 1.2% vs. 0.2% in patients without VTE (p < 0.001). After stratifying by American Society of Anesthesiologists (ASA) class, no mortality differences remained when ASA < 3. Preoperative, postoperative, and total LOSs were longer for patients with VTE (p < 0.001 for each). ASA ≥ 3, preoperative sepsis, ventilator dependence, enteral/parenteral feeding, steroid use, preoperative blood transfusion, gastrointestinal disease, hematologic disorders, operative time, and age were independent predictors (C-statistic = 0.83).

CONCLUSIONS

Pediatric postsurgical patients have unique risk factors for developing VTE.

LEVEL OF EVIDENCE

Level II.

The combination of Caprini risk assessment scale and thrombotic biomarkers to evaluate the risk of venous thromboembolism in critically ill patients

To evaluate the correlation between the Caprini risk assessment scale and plasma thrombosis biomarkers and estimate the validity of this method in identifying critically ill patients at high risk of venous thromboembolism (VTE).Patients with VTE who were admitted to the intensive care unit (ICU) department of West China Hospital SiChuan University from October 2016 to October 2017 were enrolled in this case-control study. We retrieved relative clinical data and laboratory test results included in the Caprini risk assessment scale to calculate the Caprini score and compared thrombosis biomarkers between various risk stratifications (low, moderate, high, and highest).A total of 151 critically ill patients were enrolled in our research, including 47 VTE and 94 non-VTE patients. The differences in Caprini score and levels of thrombosis biomarkers between the VTE and control group were significant. Thrombomodulin (TM) was positively correlated with Caprini score (R-value was .451, P < .05). Based on the receiver operating characteristic analysis, TM, tissue plasminogen activator-inhibitor complexes, D-dimer, and fibrinogen degradation products had a certain diagnostic efficiency in distinguishing VTE from others (P < .05). Using the logistic regression model, we identified that 5 risk factors, namely drinking history, major surgery (>3 hours), swollen legs (current), TM, and D-dimer, were independent factors for the occurrence of VTE in critically ill patients admitted in the ICU.Thrombosis markers were positively correlated with Caprini risk stratification. The combination of plasma markers and Caprini risk assessment scale can further increase the predictive value in critically ill patients with VTE.

Predicting Readmission and Reoperation for Benign Cranial Nerve Neoplasms: A Nationwide Analysis

OBJECTIVE

Readmission and reoperation are risks in the resection of benign cranial nerve tumors (BCNTs). This report analyzes the impact of patient-level and surgical factors on these adverse outcomes.

METHODS

This retrospective cohort review comprised patients with a diagnosis of BCNT enrolled in the American College of Surgeons National Surgical Quality Improvement Program registry from 2011 to 2015. Multivariate logistic regression was used to determine the impact of select medical and operative factors on the primary outcomes of readmission and reoperation within 30 days, adjusted for relevant covariates.

RESULTS

We identified 996 patients who underwent resection of a BCNT. The most frequent major complications were readmission (11%), reoperation (8%), surgical site infections (2.6%), and venous thromboembolism (1.5%). The most frequent indications for readmission were management of infection (2.5%), cerebrospinal fluid leak (2.3%), and hydrocephalus (0.5%). Repair of cranial and meningeal defects (3.0%), correction of lagophthalmos (1.2%), and repair of middle ear defects (1.0%) were the most common indications for reoperation. Logistic regression revealed that extremes of age were associated with readmission, whereas preoperative steroid usage, long operative time, and postoperative length of stay >3 days were associated with reoperation (P < 0.05). Obesity trended toward an association with readmission and reoperation.

CONCLUSIONS

Extremes of age were associated with readmission; preoperative steroid use, long operative time, and postoperative length of stay >3 days were associated with reoperation. Surgeons should consider these factors when assessing risk of postoperative complications for BCNTs.

Prolonged operative duration is associated with complications: a systematic review and meta-analysis

BACKGROUND

The aim of this study was to systematically synthesize the large volume of literature reporting on the association between operative duration and complications across various surgical specialties and procedure types.

METHODS

An electronic search of PubMed, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews from January 2005 to January 2015 was conducted. Sixty-six observational studies met the inclusion criteria.

RESULTS

Pooled analyses showed that the likelihood of complications increased significantly with prolonged operative duration, approximately doubling with operative time thresholds exceeding 2 or more hours. Meta-analyses also demonstrated a 14% increase in the likelihood of complications for every 30 min of additional operating time.

CONCLUSIONS

Prolonged operative time is associated with an increase in the risk of complications. Given the adverse consequences of complications, decreased operative times should be a universal goal for surgeons, hospitals, and policy-makers. Future study is recommended on the evaluation of interventions targeted to reducing operating time.

Comparison of a pressure-sensing sheath and radial arterial line for intraoperative blood pressure monitoring in neurointerventional procedures

Purpose

The efficiency of neuroendovascular procedures may partly depend on the time devoted to placement of a radial arterial line (RAL) for intraoperative blood pressure monitoring. An alternative approach is to use a pressure-sensing sheath (PSS) that serves to provide invasive blood pressure monitoring without requiring a separate procedure for placement. We compared the use of a RAL versus PSS and assessed procedure time, anesthetist and patient satisfaction, and cost.

Methods

We performed a single-center, prospective, blockwise, comparative trial of procedure start time using traditional RAL placement versus the EndoPhys PSS for invasive blood pressure monitoring. Endpoints included time from room arrival to groin puncture, patient and anesthetist satisfaction ratings, and costs associated with RAL placement.

Results

Twenty patients were enrolled in the PSS+RAL arm and 20 in the PSS-alone arm. Mean time from arrival in the room until groin puncture was 61.9±14.0 min in the RAL group and 51.2±10.8 min in the PSS-alone group (P=0.01; difference=10.7 min). Patients in the PSS-alone group reported less pain than those in the RAL group. Furthermore, anesthetists reported accurate blood pressure in the PSS group. The average cost estimate of RAL placement was US$774.70, with a range of US$743 to US$1171.

Conclusions

Placement of a RAL at the start of the neuroendovascular procedures resulted in increased delays to procedure start time and more patient-reported pain compared with the PSS, which may offer a more efficient means of blood pressure monitoring for neurointerventional procedures.

Clinical trial registration

NCT03239847.