Urologic Surgery

The Risk

In the 1970s, the incidence of deep vein thrombosis (DVT) in the absence of prophylaxis was 33% in patients having open urologic surgery and 9% in patients having transurethral resection (Table 4.1).^1–11 The incidence of symptomatic venous thromboembolism (VTE) is currently in the range of 0.2% to 5% and pulmonary embolism (PE) is the most common cause of postoperative death.^12–16

Table 4.1.

The Frequency of all DVTs in Patients Undergoing Urologic Surgery in the Absence of Prophylaxis (Diagnosed by Surveillance With Objective Methods: Phlebography, FUT, or DUS).^a

Patient Groups	Number of Studies	Patients, n	DVT Incidence	95% CI
Open urological operations
Becker et al 1		187	39
Mayo et al 2		41	21
Nicolaides et al 3		25	7
Hedlund et al 4		40	18
Rosenberg et al 5		32	11
Sebeseri et al 6		31	18
Kutnowski et al 7		25	12
Coe et al 8		8	1
Bergqvist and Hollbööck 9		19	6
Vandendris et al 10		33	13
Hedlund and Blomback 11		28	13
Total	11	469	159 (33%)	29%-38%
Transurethral prostatectomy
Hedlund 4		101	10
Mayo et al 2		20	2
Nicolaides et al 3		29	2
Total	3	150	14 (9%)	5%-15%

Abbreviations: CI, confidence interval; DVT, deep vein thrombosis; FUS, fibrinogen uptake test; DUS, Doppler Ultrasound.

^a The listed frequency is true for the total groups of patients. The presence of additional risk factors indicated in the text is likely to increase the risk of thromboembolism for individual patients.

A review of 16 53 275 surgical cases entered into the California Patient Discharge Data Set between January 1, 1992, and September 30, 1996 found that the incidence of symptomatic VTE was 3.7% after radical cystectomy, ¹² 2.0% after nephrectomy for malignancy compared to 0.4% in noncancer patients, and 1.5% after radical prostatectomy. Urologic procedures with a low incidence of VTE included transurethral resection of the prostate and incontinence operations. ¹²

Similar rates between 0.3% and 4.8% have been reported for laparoscopic urologic surgery,^17–20 which was shown in a single comparative study to be as hazardous as open urologic surgery. ¹⁶

Prophylactic Methods and Recommendations

General Considerations

Two small randomized studies involving 153 patients undergoing open urological procedures compared intermittent pneumatic compression (IPC) with controls.^8,21 The DVT was reduced from 14.9% to 6.3% (risk ratio [RR]; 0.43; 95% confidence interval [CI] 0.15-1.17; P = .085).

Low-dose unfractionated heparin (LDUH) was effective in reducing asymptomatic DVT in 8 randomized-controlled trials (RCTs) in which the control groups did not have prophylaxis (Figure 4.1).^{3,4,6,7,9–11} The overall incidence of DVT was reduced from 39% to 16% (RR 0.41; 95% CI 0.24-0.71).^{3,4,6–8,10,11,22} A study of 579 patients having radical prostatectomy did not find any difference in the number of pelvic lymphoceles or blood loss between those receiving LDUH and those not having prophylaxis. ²³ The RCTs to study the efficacy of LMWH for VTE prevention in patients undergoing urologic surgery have not been performed. Also, RCTs using any prophylactic modality in patients having transurethral resection are not available.

Figure 4.1.

Effect of low-dose unfractionated heparin (LDUH) versus no prophylaxis in the prevention of deep vein thrombosis (DVT) in patients who underwent urologic surgery diagnosed by surveillance with objective methods (fibrinogen uptake test and/or phlebography).^3–7,9–11

Recommendations

The LDUH (level of evidence: high) or low-molecular-weight heparin extrapolated from trials in patients having general surgery (level of evidence: low) is recommended. The IPC with graduated elastic compression is recommended in patients with increased risk of bleeding, also by extrapolation from trials in patients having general surgery (level of evidence: low).