Use of Historic Surgical Times to Predict Duration of Hysterectomy: Stratifying by Uterine Weight

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 gynecological surgery. However, the difficulty of the operation varies depending on the patient and surgeon. Subsequently, patient's outcomes and surgical efficiency are affected. We aimed to develop and validate a pre-operative nomogram to predict the operative difficulty in patients undergoing TLH.

METHODS

This retrospective study included 663 patients with TLH from XXX Hospital and 102 patients from YYY 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% confidence interval [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 pre-operative planning and patient counseling, and optimized surgical training. Further prospective multicenter clinical studies are required to optimize and validate this model.

Lack of Validity of Absolute Percentage Errors in Estimated Operating Room Case Durations as a Measure of Operating Room Performance: A Focused Narrative Review

Commonly reported end points for operating room (OR) and surgical scheduling performance are the percentages of estimated OR times whose absolute values differ from the actual OR times by ≥15%, or by various intervals from ≥5 to ≥60 minutes. We show that these metrics are invalid assessments of OR performance. Specifically, from 19 relevant articles, multiple OR management decisions that would increase OR efficiency or productivity would also increase the absolute percentage error of the estimated case durations. Instead, OR managers should check the mean bias of estimated OR times (ie, systematic underestimation or overestimation), a valid and reliable metric.

The effect of pre-analytical variables on downstream application and data analysis of human endometrial biopsies

STUDY QUESTION

What are the effects of pre-analytical variables on the downstream analysis of patient-derived endometrial biopsies?

SUMMARY ANSWER

There are distinct differences in the protein levels of the master regulator of oxygen homeostasis, hypoxia-inducible factor-1-alpha (HIF1α), and the protein and mRNA levels of three related genes, carbonic anhydrase 9 (CA9), vascular endothelial growth factor A (VEGFA) and progesterone receptor (PR) in human endometrial biopsies, depending on the pre-analytical variables: disease status (cancer vs benign), timing of biopsy (pre- vs post-hysterectomy) and type of biopsy (pipelle vs full-thickness).

WHAT IS KNOWN ALREADY

Patient-derived biopsies are vital to endometrial research, but pre-analytical variables relating to their collection may affect downstream analysis, as is evident in other tissues.

STUDY DESIGN SIZE DURATION

A prospective observational study including patients undergoing hysterectomy for endometrial cancer (EC) or benign indications was conducted at a large tertiary gynaecological unit in the UK. Endometrial biopsies were obtained at different time points (pre- or post-hysterectomy) using either a pipelle endometrial sampler or as a full-thickness wedge biopsy.

PARTICIPANTS/MATERIALS SETTING METHODS

The changes in HIF1α, CA9, VEGFA and PR protein levels were measured by semi-quantitative analysis of immunostaining, and the expression levels of three genes (CA9, VEGFA and PR) were investigated by quantitative real-time PCR, in endometrial biopsies from 43 patients undergoing hysterectomy for EC (n = 22) or benign gynaecological indications (n = 21).

MAIN RESULTS AND THE ROLE OF CHANCE

An increase in HIF1α immunostaining was observed in EC versus benign endometrium (functionalis glands) obtained pre-hysterectomy (P < 0.001). An increase in CA9 immunostaining was observed in EC versus benign endometrial functionalis glands at both pre- and post-hysterectomy time points (P = 0.03 and P = 0.003, respectively). Compared with benign endometrial pipelle samples, EC samples demonstrated increased mRNA expression of CA9 (pre-hysterectomy P < 0.001, post-hysterectomy P = 0.008) and VEGFA (pre-hysterectomy P = 0.004, post-hysterectomy P = 0.002). In benign uteri, HIF1α immunoscores (functionalis glands, P = 0.03 and stroma, P = 0.009), VEGFA immunoscores (functionalis glands, P = 0.03 and stroma, P = 0.01) and VEGFA mRNA levels (P = 0.008) were increased in matched post-hysterectomy versus pre-hysterectomy samples. Similarly, in EC, an increase in VEGFA immunoscores (epithelial and stromal) and VEGFA mRNA expression was observed in the matched post-hysterectomy versus pre-hysterectomy biopsies (P = 0.008, P = 0.004 and P = 0.018, respectively). Full-thickness benign post-hysterectomy endometrial biopsies displayed increased VEGFA (P = 0.011) and PR (P = 0.006) mRNA expression compared with time-matched pipelle biopsies.

LARGE SCALE DATA

N/A.

LIMITATIONS REASONS FOR CAUTION

This descriptive study explores the effect of pre-analytical variables on the expression of four proteins and three hypoxia-related genes in a limited number of endometrial biopsies from patients with EC and benign controls. Due to the small number, it was not possible to investigate other potential variables such as menstrual cycle phase, region-specific differences within the endometrium, grade and stage of cancer, and surgical technicalities.

WIDER IMPLICATIONS OF THE FINDINGS

Careful consideration of the effects of these pre-analytical variables is essential when interpreting data relating to human endometrial biopsies. A standardized approach to endometrial tissue collection is essential to ensure accurate and clinically transferrable data.

STUDY FUNDING/COMPETING INTERESTS

The authors have no conflicts of interest to declare. The work included in this manuscript was funded by Wellbeing of Women project grants RG1073 and RG2137 (D.K.H.), Wellbeing of Women Entry-Level Scholarship ELS706 and Medical Research Council MR/V007238/1 (A.M./D.K.H.), Liverpool Women's Hospital Cancer Charity (M.A.) and University of Liverpool (L.B., L.R. and E.N.).

Effect of length of surgery on the incidence of venous thromboembolism after benign hysterectomy

BACKGROUND

Venous thromboembolism is a leading cause of morbidity and mortality postoperatively. The current venous thromboembolism risk assessment tools have not been validated in gynecologic patients. Most patients undergoing hysterectomy for benign indications will receive mechanical or pharmacologic prophylaxis based on preoperative risk assessment. However, current guidelines do not incorporate newer data that indicate additional risk of venous thromboembolism with prolonged surgery times or mode of hysterectomy.

OBJECTIVE

This study aimed to determine the effect of length of surgery, or operative time, on the risk of venous thromboembolism within 30 days after hysterectomy and determine whether differences in the effect of operative time exist across age, body mass index, and surgical approach.

STUDY DESIGN

We performed a secondary analysis of prospectively collected surgical quality improvement data using the American College of Surgeons National Surgical Quality Improvement Program database, which contains demographic and perioperative information and 30-day postoperative outcomes from >500 hospitals, and targeted data files including procedure-specific risk factors and outcomes for a subset of hospitals. We analyzed patients undergoing abdominal, vaginal, or laparoscopic hysterectomy for benign conditions from 2014 to 2017, identified by the Current Procedural Terminology codes. We excluded patients with cancer, patients whose surgery was not performed by a gynecologist, patients who were not in the targeted files, and patients with missing operative time or with an operative time of <30 minutes. Patients were compared with respect to the incidence of venous thromboembolism and operative time, stratified by age, body mass index, and surgical approach. Multivariable logistic regression was performed; operative time was treated as a continuous, linear variable.

RESULTS

A total of 70,606 patients were included. The 30-day venous thromboembolism incidence was 0.4% (n=259). Patients with venous thromboembolism were more likely to be obese, have inpatient procedures, and had, on average, greater uterine weight. Hysterectomy approach was vaginal in 11,641 patients, laparoscopic in 41,557 patients, and abdominal in 17,408 patients. After adjustment, for each 60-minute increase in operative time, there was a 35% increase in the odds of venous thromboembolism (adjusted odds ratio, 1.35; 95% confidence interval, 1.25-1.45). Stratified by surgical approach, the odds of venous thromboembolism per 60-minute increase in operative time was greatest among abdominal hysterectomy (adjusted odds ratio, 1.49; 95% confidence interval, 1.35-1.65) compared with laparoscopic hysterectomy (adjusted odds ratio, 1.20; 95% confidence interval, 1.05-1.38) and vaginal hysterectomy (adjusted odds ratio, 1.27; 95% confidence interval, 0.97-1.66) (P=.01). Increasing body mass index and increasing age did not modify the impact of operative time on venous thromboembolism incidence (P=.66 and P=.58, respectively).

CONCLUSION

Every 60-minute increase in operative time was independently associated with a 35% increased odds of venous thromboembolism within 30 days of hysterectomy, and this risk was cumulative. Minimally invasive hysterectomy had lower odds of venous thromboembolism than abdominal hysterectomy across all time points.