PCNL is an essential component in the management of large volume renal calculi. PCNL is recommended as the most effective treatment option for patients with staghorn calculi or large volume stone disease, either as monotherapy or in combination with SWL. Multiple tracts allow for the successful management of nearly every stone burden in a single surgical session. Furthermore, patients with anatomical variations (e.g., horseshoe kidney) can be successfully treated by PCNL. Overall stone-free rates of above 78% have been described.1
Both intraoperative and postoperative bleeding are a matter of concern for any patient undergoing PCNL. Kukreja et al.12
reported an 8% blood transfusion rate in 301 PCNL procedures in patients with normal clotting parameters, and Kessaris et al. reported a 0.8% incidence of post-PCNL bleeding requiring embolization.13
In view of this, patients who need anticoagulation/antiplatelet therapy present a difficult and complex situation. The combined risk of bleeding during the reinitiation of anticoagulation/antiplatelet therapy, as well as the increased risk of thromboembolism during the withdrawal of anticoagulation/antiplatelet agents, makes a procedure such as PCNL a very risky proposition. The risk of thrombosis after stopping anticoagulation/antiplatelet therapy cannot be assessed easily for all patients. Depending on the underlying disease, primarily leading to anticoagulation, the risk of thromboembolic complications differs. In patients having mechanical heart valves, the design and location of the valves influence the risk of thrombotic complications. The complication rate can range from 0.7% to 7.6% nonfatal thromboembolic events per year and up to 1.1% fatal events per year, with the highest risk in patients with "caged ball mitral valves" and the lowest risk for patients with "bileaflet" aortic valves. Without any anticoagulation/antiplatelet therapy, the risk of major thromboembolism, including stroke and myocardial infarction, is 8%, and anticoagulation therapy reduces this risk by 75%.14
Patients with atrial fibrillation are considered at relatively low risk for thrombosis. Patients with atrial fibrillation and no coagulation have an average risk of embolism of 4.5% per year.14
With associated risk factors such as valvular atrial fibrillation, this risk can rise up to 20%.17
The risk of stent thrombosis in patients with an intracoronary stent with anticoagulation is reported to be as high as 20% within 3 months with bare metal stents, whereas the risk of stent thrombosis without anti-coagulation/antiplatelet therapy is likely to be higher.18
Alternative treatment options to PCNL must be considered before scheduling the patient for percutaneous surgery. Anticoagulation remains a contraindication for SWL. The only endoscopic treatment option that remains is the ureterorenoscopy (URS) approach. Watterson et al.19
reported their experience with ureterorenoscopic stone treatment and laser lithotripsy in patients with uncorrected bleeding diathesis. The average stone diameter was 11.9 mm and the overall stone-free rate was 96%, with bleeding complications occurring in only 3% of the treated patients. The authors concluded that URS was safe and effective, even in patients with uncorrected bleeding diathesis. However, PCNL is considered a treatment option for patients with a large stone burden, and one may definitely question the efficacy of URS in such cases. As a compromise, Ricchiuti et al.20
proposed a staged URS procedure as an alternative to PCNL. The mean stone diameter in their series was 30.9 mm, with 43.5% of patients needing a second procedure; the stone-free rates achieved were 73.9%. Despite URS remaining as a possible alternative, PCNL remains the most valuable option in patients with large renal calculi.
Klinger et al.21
retrospectively evaluated treatment protocols and the results of upper tract stone treatment in patients with clotting disorders. Over a 6-year period, 6,827 stone interventions (ESWL or endourologic procedures) were performed in 5,739 patients. Thirty-five (0.61%) patients suffered from a variety of systemic clotting disorders or were anti-coagulated. A total of 76 interventions were performed, consisting of ESWL, URS, PCNL, ureteric stenting, or percutaneous nephrostomy. URS and PCNL were successful in all cases, and complications occurred in 0% (0/7) and 33% (1/3) of patients, respectively. One patient undergoing PCNL developed significant bleeding after reversal of warfarin therapy.
Kefer et al.22
assessed the safety and efficacy of PCNL in patients requiring long-term anticoagulant therapy during the period of from 2000 to 2007. Of the 792 patients undergoing PCNL, 27 were identified to be on anticoagulant/antiplatelet therapy, which included warfarin, clopidogrel, or cilostazol. Warfarin was withheld 5 days preoperatively with enoxaparin bridging and was resumed 5 days postoperatively. Clopidogrel and cilostazol were stopped 10 days preoperatively and were resumed 5 days postoperatively. Overall, the stone-free rate with PCNL was 93% (25 of 27). A second-look procedure was required in 5 patients and a third procedure was required in 1. The mean hemoglobin decrease was 1.5 g% (range, 0-4.1 g%), and the mean change in serum creatinine was 0.03 mg% (range, 0-0.4 mg%). Two patients (7%) had significant bleeding and 1 (4%) had a thromboembolic complication. All complications were managed conservatively and all patients were stone-free at the 1-month follow-up.
Several recommendations have been made for the perioperative management of anticoagulation in patients at risk for arterial thromboembolism who are undergoing surgery.23
The approach in high-risk patients on warfarin and with atrial fibrillation (e.g., associated with prior thromboembolism, rheumatic heart disease, left ventricular dysfunction) or those with older-generation mechanical heart valves, in whom there is a fragile balance between the risk of bleeding and the risk of thromboembolism, is to administer intravenous heparin until 6 hours before the procedure and to restart heparin as soon as possible after surgery. The dose is adjusted to achieve an activated PTT that is 2.0 times control. Warfarin is then reinstituted before discharge from the hospital; the prothrombin time should be in the therapeutic range for at least 48 hours before heparin is discontinued. Antiplatelet agents should be withheld before PCNL, in which perioperative hemorrhage could be catastrophic. At least 10 days should elapse after stopping clopidogrel and before surgery is undertaken, and clopidogrel should be resumed as early as possible in the postoperative period. We have been following the protocol as shown in . Apart from these recommendations, certain surgical recommendations can be made from our study, which include using balloon dilatation for tracts, using smaller sized operating nephroscopes, preferably using a single tract, and keeping the operating time to a bare minimum.
Guidelines for the perioperative management of anticoagulation.
In conclusions, PCNL can be performed safely and effectively in patients with a large stone burden and who are on chronic anticoagulant/antiplatelet therapy with careful perioperative management of anticoagulation. Our perioperative management protocol of withdrawing and resuming anticoagulation/antiplatelet therapy is effective in our patient population. PCNL should be used as a viable option in the treatment of a large stone burden following correction of bleeding parameters.