WHAT'S IN A NAME: WHAT COMPLICATIONS IS THE NATIONAL SURGICAL QUALITY IMPROVEMENT PROGRAM "VEIN THROMBOSIS REQUIRING THERAPY� VARIABLE ACTUALLY CAPTURING?
Nicholas P. McKenna*, Katherine Bews, Rory Smoot, Kevin T. Behm, Robert R. Cima, Elizabeth B. Habermann
Mayo Clinic Minnesota, Rochester, MN
Background: Extremity deep venous thromboses (DVTs) and portomesenteric venous thromboses (PMVTs) differ in their etiology, potential sequelae, and the efficacy of pharmacologic prophylaxis in preventing their occurrence. However, the National Surgical Quality Improvement Program (NSQIP) tracks the occurrence of both extremity DVTs and PMVTs within 30 days of surgery together under its "vein thrombosis requiring therapy" variable without distinguishing the two. We therefore aimed to determine the incidence of extremity DVTs and PMVTs in patients undergoing surgery for colorectal, pancreatic, and splenic malignancies to clarify the specific complications captured under the "vein thrombosis requiring therapy" variable in NSQIP and whether further division of this variable is warranted.
Methods: Patients undergoing operations for colorectal, pancreatic, and splenic malignancies at a single institution between January 1, 2006 and March 1, 2021 were identified. Patients who experienced a new onset upper or lower extremity DVT or a PMVT within 30 days of surgery were considered cases for the study (NSQIP DVT). Patients were then stratified by cancer type, and the anatomic location of each patient's DVT (extremity or portomesenteric) was recorded. Univariate comparisons between cancer types and venous thromboembolism types were performed.
Results: A total of 8,491 operations for colorectal (n=6,003), pancreatic (n=1,496), or splenic malignancies (n=992). The overall incidence of NSQIP DVTs was 1.7%; 52% of NSQIP DVTs were PMVTs. The overall NSQIP DVT rate was highest in operations for a splenic malignancy (3.3%), followed by operations for pancreatic (2.7%) and colorectal (1.1%) malignancies (p < 0.01). After operations for pancreatic and splenic malignancies, the majority of NSQIP DVTs were either PMVTs alone or combined PMVTs plus extremity DVTs (pancreatic: 70%, splenic: 58%), while PMVTs comprised over a third of the NSQIP DVTs after surgery for colorectal malignancies (38%) (FIGURE). Of patients with an extremity DVT, 17% were also diagnosed with a pulmonary embolism (PE), compared to patients with a PMVT where a pulmonary embolism was diagnosed in only 4% of patients (p = 0.01). Lastly, PMVTs were diagnosed at a later postoperative day (median, [interquartile range]) than extremity DVTs for colorectal (19, [10-28] vs 15, [8-22]; p = 0.23) and pancreatic (21, [12-27] vs 15.5, [7-20]; p = 0.07) malignancies, but not for splenic malignancies (15 [9-22] vs 18 [12-28]); p = 0.16)
Conclusion: The current NSQIP DVT variable does not represent the full clinical picture of venous thromboembolic events after operations for colorectal, pancreatic, and splenic malignancies. The variable should be redesigned into separate "extremity DVT" and "PMVT" variables to better reflect postoperative outcomes and strengthen future research utilizing NSQIP datasets.
Incidence and Distribution of "NSQIP DVTs" Overall and by Tumor Location
Back to 2023 Abstracts