1. Incidence of postoperative venous thromboembolism in gynecologic surgery by mode of incision Elisa Jorgensen, MD Hye-Chun Hur, MD, MPH Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA

2. Background
General surgery literature has shown decreased incidence of VTE in laparoscopy (LSC) vs laparotomy1
Several risk factors for VTE may be related to mode of surgery:
Length of surgery
Type/complexity of surgery
Prolonged immobility
Length of hospital stay
**I am planning on saying all of the VTE risk factors in the presentation, including ones based on a patient’s medical comorbidities (cancer, inherited/acquired hypercoagulable state, age, obesity, prior VTE). But I wanted to highlight the ones that may be inherently related to mode of surgery so that the slide isn’t too busy

3. Background
Hysterectomy and myomectomy can both be performed through multiple modes of incision
Laparoscopy vs Laparotomy
Myomectomy: 1/2 fewer complications2
Hysterectomy: 1/3 fewer complications 3
VTE and PE are a major source of morbidity and mortality in GYN surgery4

4. Background
Caprini risk assessment model: Major open surgery >45 min and laparoscopic surgery >45 min each receive 2 points4
ACOG PB #84: stratifies VTE risk by length of surgery and patient age, not by mode of surgery6
Lack of data  many use the same parameters for VTE prophylaxis for laparotomy and laparoscopy
Pharmacologic prophylaxis can reduce risk of VTE, but increase risk of postop bleeding
Clinically meaningful – would change how we practice every single day

5. Background – Hysterectomy
Few studies of VTE in benign hysterectomy8,9  
Most use large databases: MSQC or NSQIP
Risk of VTE increases with
abdominal approach (OR  )
increased operative time (OR 1.554)
Large databases have limitations capturing outpatient surgery
FPRN data would represent the largest multicenter national sample of inpatient and outpatient hysterectomy to date

6. Background – Myomectomy
No studies assess risk of VTE with myomectomy 
Hysterectomy data cannot be directly extrapolated to myomectomy
minimally invasive approach (a protective factor) necessarily confers increased surgical time (a risk factor)  
0.45% incidence of VTE in 1,113 MMY patients at BIDMC & UMASS 
underpowered (VTE n=5) to draw conclusions regarding incidence and risk factors for VTE
seek additional data from other sites through FPRN
Internal data (to be presented at 3:25 today)
Hematoma or postop hysterectomy negates the entire reason for performing the surgery

7. Primary Aim
To assess whether mode of surgery impacts risk of postop VTE among patients undergoing gynecologic surgery (hysterectomy or myomectomy) via laparotomy versus a minimally-invasive approach (vaginal, laparoscopic, or robotic).

8. Secondary Aim
To determine patient and surgical characteristics of VTE patients to identify additional risk factors for VTE in patients undergoing hysterectomy or myomectomy, such as length of surgery
To assess variations in practice patterns for use of VTE prophylaxis in the perioperative period

9. Hypothesis Mode of incision impacts risk of postop VTE:
Patients with VTE are more likely to have undergone open hysterectomy or myomectomy vs minimally invasive approach
Despite longer length of surgery, laparoscopic hysterectomy or myomectomy is associated with a lower incidence of postop VTE vs abdominal approach.

10. Methods
Design: Case control (1:4 VTE cases to matched controls) Data collection: via electronic data mining

11. Methods Patients: Women with hysterectomy or myomectomy
Study = patients that had postoperative VTE
Control = patients without postoperative VTE, matched 4:1 with VTE
Myomectomy:
Outcomes: Type & mode of surgery analyzed by incidence of VTE; other VTE risk factors

12. Outcomes
Primary: Breakdown of mode of incision for hysterectomy and myomectomy by VTE status.
Secondary: Patient characteristics and surgical characteristics of patients with and without VTE.

13. Data to be Collected
Demographic data: Age, BMI, ASA score, cancer, prior VTE
Procedural details: Procedure (type of surgery, mode of incision), EBL, Perioperative use of mechanical or pharmacologic thromboprophylaxis, Perioperative use of prophylactic antibiotics, Length of surgery (incision to close), Length of anesthesia (induction to extubation), Length of stay
Postoperative data: Postop DVT/PE (by ICD-9/10 code), Number of readmissions, Death

14. Statistics
Proposed Analyses: Chi-square, Fisher exact test, descriptive statistics

15. Budget Total funding requested from FPRN = $0
BIDMC has resources available for statistical analysis and database construction & management

16. Items for Discussion
Accuracy of capturing all hysterectomies and myomectomies by mode of incision using CPT codes
Feasibility of electronic data mining at different institutions (institutional variability)
Structure of a multisite data extraction protocol

17. Thank you
References
Shapiro R, Vogel JD, Kiran RP. Risk of post-operative venous thromboembolism after laparoscopic and open colorectal surgery: an additional benefit of the minimally invasive approach? Disease of the Colon & Rectum. 54(12): , Dec 2011.
Jin C, Hu Y, Chen XC, et al. Laparoscopic versus open myomectomy--a meta-analysis of randomized controlled trials. Eur J Obstet Gynecol Reprod Biol. 2009;145(1):14-21.
Walker JL, Piedmonte MR, Spirtos NM, et al. Recurrence and survival after random assignment to laparoscopy versus laparotomy for comprehensive surgical staging of uterine cancer: Gynecologic Oncology Group LAP2 Study. J Clin Oncol. 2012;30(7):
Kearon C, Akl EA, Comerota AJ, Prandoni P, Kahn SR, et al. Antithrombotic therapy for VTE disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th Ed: ACCP Evidence Based Clinical Practice Guidelines. Chest 2012 Feb;141(2 Suppl)e419S-94S.
Gould MK, Garcia DA, Wren SM, et al. Prevention of VTE in Nonorthopedic Surgical Patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest ;141(2 Suppl):e227S-e277S.
ACOG Practice Bulletin No. 84: Prevention of deep vein thrombosis and pulmonary embolism. Obstet Gynecol Aug:110(2 Pt 1):429-40
Montoya, T.I., Leclaire, E.L., Oakley, S.H. et al. Int Urogynecol J (2014) 25:
Swenson CW, Berger MB, Kamdar NS, Campbell DA, Jr., Morgan DM. Risk factors for venous thromboembolism after hysterectomy. Obstet Gynecol. 2015;125(5):
Barber EL, Neubauer NL, Gossett DR. Risk of venous thromboembolism in abdominal versus minimally invasive hysterectomy for benign conditions. Am J Obstet Gynecol. 2015;212(5):609 e

18. Cases to include (by CPT code)
Laparoscopic-assisted vaginal hysterectomy (LAVH) (58550, 58552, 58553, 58554)
Laparoscopic, total hysterectomy (TLH) (58570, 58571, 58572, 58573)
Laparoscopic, supracervical hysterectomy (LSCH) (58541, 58542, 58543, 58544)
Robotic-assisted procedures (add to main procedure code)
Total abdominal hysterectomy (TAH) W/WO removal of adnexa (58150, 58152, , 58210)
Open supracervical hysterectomy (SCH) W/WO removal of adnexa (58180)
Total vaginal hysterectomy (TVH) W/WO removal of adnexa (58260, 58262,58263, , 58270, 58290, 58293, 58291, 58292, 58294, 58285, 58275, 58280)
Abdominal Myomectomy (CPT 58140, 58146),
Laparoscopic myomectomy (CPT 58545, 58546)
Robotic Myomectomy (CPT , )
Hysteroscopic/vaginal Myomectomy (CPT 58560, 58561, 58145)