Prevalence and Predictors of Venous Thromboembolism After Robot-Assisted Radical Cystectomy

Identification of key risk factors for venous thromboembolism in urological inpatients based on the Caprini scale and interpretable machine learning methods

PURPOSE

To identify the key risk factors for venous thromboembolism (VTE) in urological inpatients based on the Caprini scale using an interpretable machine learning method.

METHODS

VTE risk data of urological inpatients were obtained based on the Caprini scale in the case hospital. Based on the data, the Boruta method was used to further select the key variables from the 37 variables in the Caprini scale. Furthermore, decision rules corresponding to each risk level were generated using the rough set (RS) method. Finally, random forest (RF), support vector machine (SVM), and backpropagation artificial neural network (BPANN) were used to verify the data accuracy and were compared with the RS method.

RESULTS

Following the screening, the key risk factors for VTE in urology were "(C1) Age," "(C2) Minor Surgery planned," "(C3) Obesity (BMI > 25)," "(C8) Varicose veins," "(C9) Sepsis (< 1 month)," (C10) "Serious lung disease incl. pneumonia (< 1month) " (C11) COPD," "(C16) Other risk," "(C18) Major surgery (> 45 min)," "(C19) Laparoscopic surgery (> 45 min)," "(C20) Patient confined to bed (> 72 h)," "(C18) Malignancy (present or previous)," "(C23) Central venous access," "(C31) History of DVT/PE," "(C32) Other congenital or acquired thrombophilia," and "(C34) Stroke (< 1 month." According to the decision rules of different risk levels obtained using the RS method, "(C1) Age," "(C18) Major surgery (> 45 minutes)," and "(C21) Malignancy (present or previous)" were the main factors influencing mid- and high-risk levels, and some suggestions on VTE prevention were indicated based on these three factors. The average accuracies of the RS, RF, SVM, and BPANN models were 79.5%, 87.9%, 92.6%, and 97.2%, respectively. In addition, BPANN had the highest accuracy, recall, F1-score, and precision.

CONCLUSIONS

The RS model achieved poorer accuracy than the other three common machine learning models. However, the RS model provides strong interpretability and allows for the identification of high-risk factors and decision rules influencing high-risk assessments of VTE in urology. This transparency is very important for clinicians in the risk assessment process.

Navigating challenges in anesthesia for robotic urological surgery: a comprehensive guide

Robotic surgery has emerged as a cornerstone in urological interventions, offering effectiveness and safety for patients. For anesthesiologists, this technological advancement presents a myriad of new challenges, spanning from patient selection and assessment to intraoperative dynamics and post-surgical pain management. This article aims to elucidate these challenges and provide guidance for anesthesiologists in navigating the complexities of anesthesia administration in robotic urological procedures. Through a detailed exploration of patient optimization, team coordination, intraoperative adjustments, and post-surgical care, this article serves as a valuable resource for ensuring the success of such interventions.

Can We Go beyond Pathology? The Prognostic Role of Risk Scoring Tools for Cancer-Specific Survival of Patients with Bladder Cancer Undergoing Radical Cystectomy

Radical cystectomy (RC) remains a mainstay surgical treatment for non-metastatic muscle-invasive and BCG-unresponsive bladder cancer. Various perioperative scoring tools assess comorbidity burden, complication risks, and cancer-specific mortality (CSM) risk. We investigated the prognostic value of these scores in patients who underwent RC between 2015 and 2021. Cox proportional hazards were used in survival analyses. Risk models' accuracy was assessed with the concordance index (C-index) and area under the curve. Among 215 included RC patients, 63 (29.3%) died, including 53 (24.7%) cancer-specific deaths, with a median follow-up of 39 months. The AJCC system, COBRA score, and Charlson comorbidity index (CCI) predicted CSM with low accuracy (C-index: 0.66, 0.65; 0.59, respectively). Multivariable Cox regression identified the AJCC system and CCI > 5 as significant CSM predictors. Additional factors included the extent of lymph node dissection, histology, smoking, presence of concomitant CIS, and neutrophil-to-lymphocyte ratio, and model accuracy was high (C-index: 0.80). The internal validation of the model with bootstrap samples revealed its slight optimism of 0.06. In conclusion, the accuracy of the AJCC staging system in the prediction of CSM is low and can be improved with the inclusion of other pathological data, CCI, smoking history and inflammatory indices.

Outcomes from a prospectively implemented protocol using apixaban after robot-assisted radical cystectomy

OBJECTIVES

To compare the safety and efficacy of oral apixaban with that of injectable enoxaparin after robot-assisted radical cystectomy (RARC) for venous thromboembolism (VTE) thromboprophylaxis.

MATERIALS AND METHODS

We conducted a retrospective review of prospectively collected data for all RARC patients treated at our tertiary care centre between 2018 and 2022. The study included two groups: patients who were subject to a prospectively implemented protocol from October 2021 to the present, comprising a 21-day postoperative course of apixaban 2.5 mg twice daily after discharge, and patients treated prior to October 2021 who received enoxaparin 40 mg daily. Baseline demographics and clinical characteristics, such as VTE (defined as deep vein thrombosis and pulmonary embolism), were analysed. The primary outcome was incidence of symptomatic VTE confirmed with definitive imaging within 90 days of RARC. Secondary outcomes included major bleeding, complications, readmission, and mortality within 30 days postoperatively. Descriptive statistics included baseline patient characteristics, operative information and complications. Differences in baseline characteristics and postoperative data were compared between groups. Multivariate logistic regression was used to determine associations between variables and the primary outcome.

RESULTS

A total of 124 patients received apixaban and 250 patients received enoxaparin prophylaxis. Ten patients (2.7%) experienced a VTE within 90 days postoperatively (two [1.6%] apixaban group vs eight [3.2%] enoxaparin group; P = 0.5). After patient stratification into European Association of Urology risk groups, no statistically significant difference in VTE rates was seen between groups in the apixaban (2.7% high- + intermediate-risk group vs 1.1% low-risk group; P = 0.5) and enoxaparin cohorts (4.3% high- + intermediate-risk group vs 2.5% low-risk group; P = 0.5). On multivariate logistic regression, no variables were associated with the development of the primary outcome.

CONCLUSION

Prophylaxis with apixaban and enoxaparin showed no statistically significant differences in VTE rates among RARC patients. Apixaban appears to be safe and effective for VTE prophylaxis after RARC.

Incidence and location of perioperative deep vein thrombosis in patients with bladder cancer undergoing radical cystectomy

OBJECTIVES

To determine the incidence and location of lower extremity deep vein thrombosis in patients undergoing radical cystectomy.

METHODS

We performed radical cystectomy in 137 patients with bladder cancer between August 2014 and February 2020. Since 2014, we have had a policy to screen for deep vein thrombosis using lower extremity ultrasonography both before and after radical cystectomy. We determined the incidence and location of deep vein thrombosis and classified it as either proximal or distal type. Furthermore, we explored the incidence of pulmonary embolism within 3 months after radical cystectomy.

RESULTS

After excluding six patients with a lack of ultrasonographic data, we evaluated 131 patients. Preoperative deep vein thrombosis (one proximal and 17 distal) was diagnosed in 18 patients (14%) with no symptoms. Postoperative deep vein thrombosis was diagnosed in 41 patients (31%; three proximal and 38 distal), of whom 26 (63%) had new-onset deep vein thrombosis after cystectomy. Three patients, two with proximal and one with distal type deep vein thrombosis, developed nonfatal pulmonary embolism postoperatively. Multivariate analysis showed that preoperative D-dimer levels (odds ratio 5.35, 95% confidence interval 1.74-16.50; P < 0.003), type of urinary diversion (ileal neobladder; odds ratio 11.15, 95% confidence interval 2.16-57.55; P = 0.004), and preoperative deep vein thrombosis (odds ratio 15.93, 95% confidence interval 3.82-66.30; P < 0.001) were significant risk factors for postoperative deep vein thrombosis.

CONCLUSIONS

Pre- and post-radical cystectomy whole-leg ultrasonography can lead to an early perioperative diagnosis and immediate treatment of proximal deep vein thrombosis, thereby potentially preventing fatal pulmonary embolism.

Direct Oral Anticoagulants for Venous Thromboembolism Prophylaxis Following Robot-assisted Radical Cystectomy: A Retrospective Feasibility Study at a Single Academic Medical Center

OBJECTIVES

To evaluate the use of direct oral anticoagulants following radical cystectomy for venous thromboembolism prophylaxis. We compared the experience of those who received venous thromboembolism prophylaxis following a robot-assisted radical cystectomy with either a direct oral anticoagulant or enoxaparin.

METHODS

Medical records of 66 patients who underwent robot-assisted radical cystectomy between July 2017 and May 2020 at a single academic institution were reviewed retrospectively. Patients received extended prophylaxis with either a direct oral anticoagulant or enoxaparin before or following surgical discharge. Venous thromboembolic events and complications resulting in emergency department visits and readmissions were reviewed over a 90-day postoperative period.

RESULTS

A total of 4 venous thromboembolic events within 90 days of surgery were observed. Among patients taking enoxaparin, 5% (2/37) developed a deep vein thrombosis and 3% (1/37) developed a pulmonary embolism. Among patients taking direct oral anticoagulants, 3% (1/29) developed a deep vein thrombosis. Zero patients in the enoxaparin group and 3% (1/29) of patients in the direct oral anticoagulant group experienced bleeding that required an emergency department visit.

CONCLUSION

Direct oral anticoagulants performed comparably to enoxaparin in this feasibility study following robot-assisted radical cystectomy in 66 patients. No significant differences in the number of venous thromboembolisms or bleeding complications were observed. These data encourage future studies and support the prospect of direct oral anticoagulants as a potentially suitable oral alternative to injectable low molecular weight heparins for venous thromboembolism prophylaxis following radical cystectomy.