Predictive Factor of Conversion to Laparotomy in Minimally Invasive Surgical Staging for Endometrial Cancer

Incorporating low haemoglobin into a risk prediction model for conversion in minimally invasive gynaecologic oncology surgeries

BACKGROUND

A well-known complication of laparoscopic management of gynaecologic masses and cancers is the need to perform an intraoperative conversion to laparotomy. The purpose of this study was to identify novel patient risk factors for conversion from minimally invasive to open surgeries for gynaecologic oncology operations.

METHODS

This was a retrospective cohort study of 1356 patients ≥18 years of age who underwent surgeries for gynaecologic masses or malignancies between February 2015 and May 2020 at a single academic medical centre. Multivariable logistic regression was used to study the effects of older age, higher body mass index (BMI), higher American Society of Anaesthesiologist (ASA) physical status, and lower preoperative haemoglobin (Hb) on odds of converting from minimally invasive to open surgery. Receiver operating characteristic (ROC) curve analysis assessed the discriminatory ability of a risk prediction model for conversion.

RESULTS

A total of 704 planned minimally invasive surgeries were included with an overall conversion rate of 6.1% (43/704). Preoperative Hb was lowest for conversion cases, compared to minimally invasive and open cases (11.6 ± 1.9 vs 12.8 ± 1.5 vs 11.8 ± 1.9 g/dL, p<.001). Patients with preoperative Hb <10 g/dL had an adjusted odds ratio (OR) of 3.94 (CI: 1.65-9.41, p=.002) for conversion while patients with BMI ≥30 kg/m2 had an adjusted OR of 2.86 (CI: 1.50-5.46, p=.001) for conversion. ROC curve analysis using predictive variables of age >50 years, BMI ≥30 kg/m2, ASA physical status >2, and preoperative haemoglobin <10 g/dL resulted in an area under the ROC curve of 0.71. Patients with 2 or more risk factors were at highest risk of requiring an intraoperative conversion (12.0%).

CONCLUSIONS

Lower preoperative haemoglobin is a novel risk factor for conversion from minimally invasive to open gynaecologic oncology surgeries and stratifying patients based on conversion risk may be helpful for preoperative planning.

Nomogram for predicting difficult total laparoscopic hysterectomy: a multi-institutional, retrospective model development and validation study

BACKGROUND

Total laparoscopic hysterectomy (TLH) is the most commonly performed gynaecological surgery. However, the difficulty of the operation varies depending on the patient and surgeon. Subsequently, patient's outcomes and surgical efficiency are affected. The authors aimed to develop and validate a preoperative nomogram to predict the operative difficulty in patients undergoing TLH.

METHODS

This retrospective study included 663 patients with TLH from Southwest Hospital and 102 patients from 958th Hospital in Chongqing, China. A multivariate logistic regression analysis was used to identify the independent predictors of operative difficulty, and a nomogram was constructed. The performance of the nomogram was validated internally and externally.

RESULTS

The uterine weight, history of pelvic surgery, presence of adenomyosis, surgeon's years of practice, and annual hysterectomy volume were identified as significant independent predictors of operative difficulty. The nomogram demonstrated good discrimination in the training dataset [area under the receiver operating characteristic curve (AUC), 0.827 (95% CI, 0.783-0.872], internal validation dataset [AUC, 0.793 (95% CI, 0.714-0.872)], and external validation dataset [AUC, 0.756 [95% CI, 0.658-0.854)]. The calibration curves showed good agreement between the predictions and observations for both internal and external validations.

CONCLUSION

The developed nomogram accurately predicted the operative difficulty of TLH, facilitated preoperative planning and patient counselling, and optimized surgical training. Further prospective multicenter clinical studies are required to optimize and validate this model.

Perioperative outcomes and disparities in utilization of sentinel lymph node biopsy in minimally invasive staging of endometrial cancer

OBJECTIVE

To assess the emergence of sentinel lymph node biopsy (SLNB) for disparities in utilization, and impacts on perioperative outcomes.

METHODS

Retrospective cohort study of the National Cancer Database, selecting for patients with T1NxM0 endometrial cancer undergoing minimally invasive surgical staging from 2012 to 2016. Disparities in SLNB utilization were described. Propensity matching was performed. Association of SLNB with perioperative outcomes was assessed with logistic regression.

RESULTS

Among 67,365 patients, 6356 (9.4%) underwent SLNB, increasing from 2.8% to 16.3% from 2012 to 2016. Disparities were identified within race (7.0% Black, 9.4% non-Black), ethnicity (8.3% Hispanic, 9.5% non-Hispanic), insurance (6.0% uninsured, 9.5% insured), county density (3.7% rural, 9.8% metro), and income (7.0% bottom-quartile, 11.8% top-quartile). Risk of conversion to open surgery was lower with SLNB alone (1.03%) or SLNB followed by LND (1.40%), versus upfront LND (2.80%). SLNB was associated with reduced risk of conversion to open surgery in Intention-To-Treat (SLNB+/-LND vs. upfront LND; OR_ITT = 0.53; 95%CI 0.39-0.72) and Per-Protocol (PP; SLNB alone vs. upfront LND or SLNB+LND; OR_PP = 0.49; 95%CI 0.32-0.75) comparisons. SLNB was also associated with lower risk of length of stay >1 day (overall rate 6.3%; OR_ITT = 0.51; 95%CI 0.40-0.64; OR_PP = 0.39; 95%CI 0.28-0.55), and unplanned readmission (overall rate 2.3%; OR_PP = 0.52; 95%CI 0.33-0.81). There were no deaths within 90 days among 1370 SLNB alone cases, versus 2/1294 (0.15%) for SLNB+LND, and 123/28,828 (0.41%) for upfront LND.

CONCLUSION

We identified significant disparities in the utilization of SLNB, as well as evidence that this less-invasive technique is associated with lower rates of certain perioperative complications. Equitable access to this emerging technique could lessen disparate outcomes.

Laparoscopic and robotic hysterectomy in endometrial cancer patients with obesity: a systematic review and meta-analysis of conversions and complications

OBJECTIVE DATA

Robotic assistance may facilitate completion of minimally invasive hysterectomy, which is the standard of care for the treatment of early-stage endometrial cancer, in patients for whom conventional laparoscopy is challenging. The aim of this systematic review was to assess conversion to laparotomy and perioperative complications after laparoscopic and robotic hysterectomy in patients with endometrial cancer and obesity (body mass index, ≥30 kg/m²).

STUDY

We systematically searched MEDLINE, EMBASE, and Evidence-Based Medicine Reviews (January 1, 2000, to July 18, 2018) for studies of patients with endometrial cancer and obesity (body mass index, ≥30 kg/m²) who underwent primary hysterectomy.

STUDY APPRAISAL AND SYNTHESIS METHODS

We determined the pooled proportions of conversion, organ/vessel injury, venous thromboembolism, and blood transfusion. We assessed risk of bias with the Institute of Health Economics Quality Appraisal Checklist for single-arm studies, and Newcastle-Ottawa Quality Scale for double-arm studies.

RESULTS

We identified 51 observational studies that reported on 10,800 patients with endometrial cancer and obesity (study-level body mass index, 31.0-56.3 kg/m²). The pooled proportions of conversion from laparoscopic and robotic hysterectomy were 6.5% (95% confidence interval, 4.3-9.9) and 5.5% (95% confidence interval, 3.3-9.1), respectively, among patients with a body mass index of ≥30 kg/m², and 7.0% (95% confidence interval, 3.2-14.5) and 3.8% (95% confidence interval, 1.4-9.9) among patients with body mass index of ≥40 kg/m². Inadequate exposure because of adhesions/visceral adiposity was the most common reason for conversion for both laparoscopic (32%) and robotic hysterectomy (61%); however, intolerance of the Trendelenburg position caused 31% of laparoscopic conversions and 6% of robotic hysterectomy conversions. The pooled proportions of organ/vessel injury (laparoscopic, 3.5% [95% confidence interval, 2.2-5.5]; robotic hysterectomy, 1.2% [95% confidence interval, 0.4-3.4]), venous thromboembolism (laparoscopic, 0.5% [95% confidence interval, 0.2-1.2]; robotic hysterectomy, 0.5% [95% confidence interval, 0.1-2.0]), and blood transfusion (laparoscopic, 2.8% [95% confidence interval, 1.5-5.1]; robotic hysterectomy, 2.1% [95% confidence interval, 1.6-3.8]) were low and not appreciably different between arms.

CONCLUSION

Robotic and laparoscopic hysterectomy have similar rates perioperative complications in patients with endometrial cancer and obesity, but robotic hysterectomy may reduce conversions because of positional intolerance in patients with morbid obesity. Existing literature is limited by selection and confounding bias, and randomized trials are needed to inform practice standards in this population.

Measurement error and timing of predictor values for multivariable risk prediction models are poorly reported

OBJECTIVE

Measurement error in predictor variables may threaten the validity of clinical prediction models. We sought to evaluate the possible extent of the problem. A secondary objective was to examine whether predictors are measured at the intended moment of model use.

METHODS

A systematic search of Medline was used to identify a sample of articles reporting the development of a clinical prediction model published in 2015. After screening according to a predefined inclusion criteria, information on predictors, strategies to control for measurement error, and intended moment of model use were extracted. Susceptibility to measurement error for each predictor was classified into low and high risks.

RESULTS

Thirty-three studies were reviewed, including 151 different predictors in the final prediction models. Fifty-one (33.7%) predictors were categorized as high risk of error; however, this was not accounted for in the model development. Only 8 (24.2%) studies explicitly stated the intended moment of model use and when the predictors were measured.

CONCLUSION

Reporting of measurement error and intended moment of model use is poor in prediction model studies. There is a need to identify circumstances where ignoring measurement error in prediction models is consequential and whether accounting for the error will improve the predictions.

Association between Obesity, Surgical Route, and Perioperative Outcomes in Patients with Uterine Cancer

Objective

To study temporal trends of hysterectomy routes performed for uterine cancer and their associations with body mass index (BMI) and perioperative morbidity.

Methods

A retrospective review of the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) 2005-2013 databases was conducted. All patients who were 18 years old and older with a diagnosis of uterine cancer and underwent hysterectomy were identified using ICD-9-CM and CPT codes. Surgical route was classified into four groups: total abdominal hysterectomy (TAH), total vaginal hysterectomy (TVH), laparoscopic assisted vaginal hysterectomy (LAVH), and total laparoscopic hysterectomy (TLH) including both conventional and robotically assisted. Patients were then stratified according to BMI.

Results

7199 records were included in the study. TLH was the most commonly performed route of hysterectomy regardless of BMI, with proportions of 50.9%, 48.9%, 50.4%, and 51.2% in ideal, overweight, obese, and morbidly obese patients, respectively. The median operative time for TAH was 2.2 hours compared to 2.7 hours for TLH (p < 0.01). The median length of stay for TAH was 3 days compared to 1 day for TLH (p < 0.01). The percentage of patients with an adverse outcome (composite indicator including transfusion, deep venous thrombosis, and infection) was 17.1 versus 3.7 for TAH and TLH, respectively (p < 0.01).

Conclusion

During the last decade, TLH has been increasingly performed in women with uterine cancer. The increased adoption of TLH was seen in all BMI subgroups.

Considerations for minimally invasive gynecologic surgery in obese patients

PURPOSE OF REVIEW

The purpose is to review the key anatomical and physiological changes in obese patients and their effects on preoperative, intraoperative, and postoperative care and to highlight the best practices to safely extend minimally invasive approaches to obese patients and provide optimal surgical outcomes in this high-risk population.

RECENT FINDINGS

Minimally invasive surgery is safe, feasible, and cost-effective for obese patients. Obesity is associated with anatomical and physiological changes in almost all organ systems, which necessitates a multimodal approach and an experienced, multidisciplinary team. Preoperative counseling, evaluation, and optimization of medical comorbidities are critical. The optimal minimally invasive approach is primarily determined by the patient's anatomy and pathology. Specific intraoperative techniques and modifications exist to maximize surgical exposure and panniculus management. Postoperatively, comprehensive medical management can help prevent common complications in obese patients, including hypoxemia, venous thromboembolism, acute kidney injury, hyperglycemia, and prolonged hospitalization.

SUMMARY

Given significantly improved patient outcomes, minimally invasive approaches to gynecological surgery should be considered for all obese patients with particular attention given to specific perioperative considerations and appropriate referral to an experienced minimally invasive surgeon.