From the Guidelines
Appendectomy is not a significant risk factor for portal vein thrombosis (PVT). While any abdominal surgery carries a small risk of venous thromboembolism, appendectomy specifically has not been established as a common cause of portal vein thrombosis, as noted in the American College of Chest Physicians evidence-based clinical practice guidelines 1. Portal vein thrombosis is more commonly associated with conditions such as cirrhosis, malignancy, inflammatory bowel disease, pancreatitis, or hypercoagulable states. The portal venous system is anatomically distant from the appendix, making direct involvement unlikely during a routine appendectomy.
Some key points to consider in assessing the risk of VTE in surgical patients include:
- Patient-specific factors such as age, prior VTE, and cancer
- Procedure-specific factors, with open-abdominal and open-pelvic procedures associated with a higher risk of VTE
- The use of thromboprophylaxis measures, such as early mobilization and pharmacological prophylaxis with low molecular weight heparin in higher-risk patients, as outlined in the Caprini Risk Assessment Model 1
Standard thromboprophylaxis measures used during and after surgery are typically sufficient to prevent venous thrombotic complications. If a patient develops symptoms like abdominal pain, ascites, or signs of portal hypertension after appendectomy, imaging studies such as Doppler ultrasound or CT with contrast would be appropriate to evaluate for this rare complication. The risk of symptomatic VTE in the 12 weeks following inpatient surgery is almost as high in vascular surgery patients as it is in those who have surgery for cancer, but appendectomy is considered a relatively low-risk procedure 1.
In terms of specific risk factors for VTE, the Caprini model identifies factors such as age, history of VTE, and malignancy as increasing the risk of VTE 1. However, appendectomy is not specifically identified as a high-risk procedure in this model. Overall, while any surgery carries some risk of VTE, appendectomy is not generally considered a significant risk factor for portal vein thrombosis.
From the Research
Portal Vein Thrombosis Risk Factors
The provided studies do not directly address appendectomy as a risk factor for portal vein thrombosis. However, they do discuss various risk factors and surgical procedures associated with portal vein thrombosis:
- Intra-abdominal surgery, including colectomy, bariatric surgery, and splenectomy, has been linked to portal vein thrombosis 2
- Laparoscopic splenectomy and pericardial devascularization may increase the risk of portal vein system thrombosis, with risk factors including diabetes, portal vein diameter, splenic vein diameter, and portal blood flow velocity 3
- Splenectomy, whether open or laparoscopic, carries a risk of portal vein thrombosis, with potential risk factors including spleen size and underlying hematologic diseases 4
- A meta-analysis identified risk factors for portal vein system thrombosis after splenectomy, including larger spleen volume, broader splenic vein diameter, broader portal vein diameter, lower velocity of portal blood flow, ascites, bleeding history, and decreased platelet count, white blood cell, and hemoglobin 5
- Liver resection may also increase the risk of portal vein thrombosis, with risk factors including long duration of Pringle's maneuver and portal vein segmental resection 6
Surgical Procedures and Portal Vein Thrombosis
While the studies do not specifically mention appendectomy as a risk factor, they do highlight the importance of considering the potential risks of portal vein thrombosis after various surgical procedures: