Since its first description, PN has been one of the most commonly performed procedures in daily urological practice (1). Since Pedersen’s description of ultrasound-guided PN alone, it has also become feasible even in the office setting (12). With the increasing image quality of modern ultrasound equipment, the success rate of PN placement in the office setting has reached 100% in dilated kidneys (13). In our study, all patients had a grade ≥ 2 renal dilatation degree, and the technical success rate of PN placement was 100% in all patients.
Bleeding diathesis is a relative contraindication for PN placement; however, if intravascular coagulopathy develops due to urosepsis, it is unlikely that the patient’s condition can be corrected without PN (6,7).
Decompression of the infected kidney via PN provides clinical improvement, particularly in patients who cannot tolerate major surgery and anaesthesia. During this time, the patient can be more closely ecaluated, potential fluid-electrolyte imbalances can be corrected, the infection can be managed, and valuable time can be gained in preparation for subsequent surgical intervention.
Following PN placement, major complications such as bleeding, sepsis, and injury to adjacent organs have been reported in 3% to 4% of cases (14). The rate of nephrectomy due to bleeding after PN has been reported to be less than 1% (9). In our study, no patient experienced major complications, such as adjacent organ injury or nephrectomy.
In situations involving obstructive pyelonephritis, pyonephrosis, renal-retroperitoneal abscess, and urosepsis, the primary therapeutic approach is urgent decompression through either percutaneous nephrostomy (PN) or placement of a double-J (D-J) stent (15). Furthermore, in cases of pyonephrosis and abscess drainage, the lumen of a D-J stent may be insufficient to adequately drain dense contents or pus.
Emergency nephrectomy is generally favored in the management of emphysematous pyelonephritis, and in current practice, urgent PN is often the first therapeutic step. In a retrospective study of 20 patients with emphysematous pyelonephritis, Shokeir et al. reported a mortality rate of 20% associated with emergency nephrectomy (3). A systematic review of 210 patients diagnosed with emphysematous pyelonephritis, the reported mortality rates were 25% and 13.5% for emergency nephrectomy and PN, respectively (16). Emergency PN makes delayed nephrectomy more reasonable under more stable conditions after achieving clinical improvement. None of our patients with emphysematous pyelonephritis underwent emergency nephrectomy. Elective nephrectomy was performed in 3 patients with emphysematous pyelonephritis 2 months after PN placement.
Numerous studies have reported that the incidence of major bleeding in patients taking warfarin without surgery ranges from 0.4% to 7.2% per year, while the incidence of minor bleeding can be as high as 15.4% per year (17). In the AVERROES trial, which included 5599 patients, the bleeding rate was 3.8%/year with aspirin and 4.5%/year with apixaban (a new-generation anticoagulant), 18). The use of low-dose acetylsalicylic acid has been shown to increase the risk of major bleeding by about 1.5 times, and chronic diseases such as diabetes mellitus and older age are independent factors that increase the risk of bleeding (19,20). In addition, RCTs reported an equivalent risk of major bleeding with aspirin or clopidogrel compared with warfarin. Bleeding of any severity and intracranial bleeding are less common with antiplatelet drugs than with warfarin (21).
PN placement in patients receiving antithrombotic therapy is known to be associated with a high risk of bleeding (6,7,10). Some studies have suggested that antithrombotics do not increase intraoperative blood loss during emergency gastrointestinal surgery (22,23). However, there is a lack of sufficient data on emergency surgery in patients receiving antithrombotic therapy. To the best of our knowledge, this is the first case-control study of investigating PN placement in patients receiving antithrombotic therapy. According to the results of our study, although the antithrombotic group had a higher rate of chronic disease and a higher mean age of patients, no difference was found between the groups in terms of bleeding complications and Hg lowering.
In our study, emergency PN in patients on antithrombotic medication appeared to be generally safe with low complication rates. The fact that the majority of our patients had grade 2 or higher hydronephrosis and that kidney access was achieved with a single needle puncture in all patients supports the low complication rates. The fact that none of our patients had renal hemorrhage requiring additional intervention after PN supports the fact that emergency PN can be performed when necessary, taking into account the risk/benefit ratio.
The indication for emergency PN in patients on antithrombotic therapy is a rare clinical scenario and resulting in a small sample size. The retrospective nature of the study and the relatively small sample size are the main limitations that may have influenced the results. Prospective randomized controlled trials with large number of patients are needed to determine the safety and clear limits of the applicability of PN in patients on antithrombotic therapy.
DISCUSSION
Since its first description, PN has been one of the most commonly performed procedures in daily urological practice (1). Since Pedersen’s description of ultrasound-guided PN alone, it has also become feasible even in the office setting (12). With the increasing image quality of modern ultrasound equipment, the success rate of PN placement in the office setting has reached 100% in dilated kidneys (13). In our study, all patients had a grade ≥ 2 renal dilatation degree, and the technical success rate of PN placement was 100% in all patients.
Bleeding diathesis is a relative contraindication for PN placement; however, if intravascular coagulopathy develops due to urosepsis, it is unlikely that the patient’s condition can be corrected without PN (6,7).
Decompression of the infected kidney via PN provides clinical improvement, particularly in patients who cannot tolerate major surgery and anaesthesia. During this time, the patient can be more closely ecaluated, potential fluid-electrolyte imbalances can be corrected, the infection can be managed, and valuable time can be gained in preparation for subsequent surgical intervention.
Following PN placement, major complications such as bleeding, sepsis, and injury to adjacent organs have been reported in 3% to 4% of cases (14). The rate of nephrectomy due to bleeding after PN has been reported to be less than 1% (9). In our study, no patient experienced major complications, such as adjacent organ injury or nephrectomy.
In situations involving obstructive pyelonephritis, pyonephrosis, renal-retroperitoneal abscess, and urosepsis, the primary therapeutic approach is urgent decompression through either percutaneous nephrostomy (PN) or placement of a double-J (D-J) stent (15). Furthermore, in cases of pyonephrosis and abscess drainage, the lumen of a D-J stent may be insufficient to adequately drain dense contents or pus.
Emergency nephrectomy is generally favored in the management of emphysematous pyelonephritis, and in current practice, urgent PN is often the first therapeutic step. In a retrospective study of 20 patients with emphysematous pyelonephritis, Shokeir et al. reported a mortality rate of 20% associated with emergency nephrectomy (3). A systematic review of 210 patients diagnosed with emphysematous pyelonephritis, the reported mortality rates were 25% and 13.5% for emergency nephrectomy and PN, respectively (16). Emergency PN makes delayed nephrectomy more reasonable under more stable conditions after achieving clinical improvement. None of our patients with emphysematous pyelonephritis underwent emergency nephrectomy. Elective nephrectomy was performed in 3 patients with emphysematous pyelonephritis 2 months after PN placement.
Numerous studies have reported that the incidence of major bleeding in patients taking warfarin without surgery ranges from 0.4% to 7.2% per year, while the incidence of minor bleeding can be as high as 15.4% per year (17). In the AVERROES trial, which included 5599 patients, the bleeding rate was 3.8%/year with aspirin and 4.5%/year with apixaban (a new-generation anticoagulant), 18). The use of low-dose acetylsalicylic acid has been shown to increase the risk of major bleeding by about 1.5 times, and chronic diseases such as diabetes mellitus and older age are independent factors that increase the risk of bleeding (19,20). In addition, RCTs reported an equivalent risk of major bleeding with aspirin or clopidogrel compared with warfarin. Bleeding of any severity and intracranial bleeding are less common with antiplatelet drugs than with warfarin (21).
PN placement in patients receiving antithrombotic therapy is known to be associated with a high risk of bleeding (6,7,10). Some studies have suggested that antithrombotics do not increase intraoperative blood loss during emergency gastrointestinal surgery (22,23). However, there is a lack of sufficient data on emergency surgery in patients receiving antithrombotic therapy. To the best of our knowledge, this is the first case-control study of investigating PN placement in patients receiving antithrombotic therapy. According to the results of our study, although the antithrombotic group had a higher rate of chronic disease and a higher mean age of patients, no difference was found between the groups in terms of bleeding complications and Hg lowering.
In our study, emergency PN in patients on antithrombotic medication appeared to be generally safe with low complication rates. The fact that the majority of our patients had grade 2 or higher hydronephrosis and that kidney access was achieved with a single needle puncture in all patients supports the low complication rates. The fact that none of our patients had renal hemorrhage requiring additional intervention after PN supports the fact that emergency PN can be performed when necessary, taking into account the risk/benefit ratio.
The indication for emergency PN in patients on antithrombotic therapy is a rare clinical scenario and resulting in a small sample size. The retrospective nature of the study and the relatively small sample size are the main limitations that may have influenced the results. Prospective randomized controlled trials with large number of patients are needed to determine the safety and clear limits of the applicability of PN in patients on antithrombotic therapy.