Tranexamic Acid in Percutaneous Nephrolithotomy
Condition: Percutaneous Nephrolithotomy; Intraoperative Use of Tranexamic Acid
Study type: Interventional

Summary: 
      Tranexamic acid, once a randomly used antifibrinolytic agent, has been in standard protocols
      for many specific surgeries. Studies are still needed to standardize the dose and route of
      tranexamic acid administration, examine its possible contributions in urological surgery, and
      establish a protocol for its use.

      To contribute to this goal, the study was designed as a prospective, randomized, double-blind
      study on 75 patients with one control and 2 study groups (n=25) who underwent percutaneous
      nephrolithotomy. Group Tranexamic acid received 10 mg/kg intravenous tranexamic acid
      preoperatively. And Group Irrigation received the same amount in the initial irrigation
      fluid. Primarily,the total amount of blood transfusion and the changes in haemoglobin and
      haematocrit values during two postoperative days were observed. Distinctively, continuous
      intraoperative haemoglobin saturation was monitored. Secondarily, surgical visual clarity
      with a standard visual score was questioned to reveal its contribution to surgical
      practicality, operative time, and residual fragment quantity.
    

Detailed description: 
      The study was designed as a double-blind, prospective, randomised, controlled study after
      approval of our Institutional ethics committee (dossier no: 108-2021) and assessed patients
      scheduled for PCNL after January 2022 for eligibility. After obtaining written informed
      consent, 75 patients (3 groups; 1:1:1 distribution; n=25) were allocated, and the study was
      conducted in Haseki Training and Research Hospital until May 2023, with the principles
      outlined in the Helsinki Declaration.

      Study subjects The study population was 18-70 years old and ASA I-III patients scheduled for
      PCNL surgery. Exclusion criteria were tranexamic acid hypersensitivity, history of
      subarachnoid haemorrhage, previous cerebrovascular event, a history of arterial-venous
      embolism or a tendency to thromboembolism, abnormal liver function tests, unstable
      cardiovascular disease, acute or chronic renal failure, presence of any haematological
      disease and known colour blindness.

      Patient randomization and blindness Randomization was designed as 3 (n= 25) named Groups A,
      B, and Group C in a 1:1:1 ratio with a computer-based algorithm and sealed in opaque
      envelopes by the surgeon assigned to the study. The investigative anesthesiologist selected
      an envelope in the order of numbers on it, and Group A continued with an IV infusion of 10
      mg/kg tranexamic acid for 20 minutes just before the surgical incision. In Group B, 10 mg/kg
      tranexamic acid was placed in the first irrigation solution; in Group C, no drug was given
      either way. The urologist was blind to the study groups and was the evaluator of an
      intraoperative visual score. Postoperative Hb and Hct values and complications were followed
      by the surgeons who were also blinded to the groups, and the decision of blood replacement
      was made according to the Hct values according to our standard protocol of the urology
      department.

      Anaesthesia and surgical technique All surgeries were performed under general anaesthesia
      with standard monitorisation and non-invasive MASIMO Hemoglobin (SpHb®) real-time monitoring.
      After the ureteral catheter was placed, the patient was placed in a prone position. After
      sequential dilatations were performed under fluoroscopy, a 16.5 Fr or 21 Fr am Platz sheath
      was placed in the pelvicalyceal system. Ho: YAG Laser lithotripter (Sphinx, Lisa laser, USA)
      was used to fragment stones. According to the surgeon's decision, a JJ stent and/or a
      nephrostomy tube were placed at the final of the operation.

      Primary outcome The primary outcome was the comparison of changes in haemoglobin and
      haematocrit values during two postoperative days with changes in intraoperative SpHb values
      and postoperative need for blood transfusion. SpHb was monitored throughout the surgery;
      however, the value of change before and immediately after surgery was a major concern. Blood
      samples were evaluated for Hb and Hct values on the first night and the second morning after
      surgery. Indications for blood transfusion were below 30% hematocrit level.

      Secondary outcomes The effect on surgical outcomes was questioned by residual fragment (%)
      and postoperative complications. The effect on surgical practice was evaluated by operation
      time (minute) and visual score of the surgeon. At the end of the surgery, the assigned
      surgeon who was blind to the groups was asked to rate the visual clarity by a score
      pre-designed for arthroscopic surgeries as 'Bad-Medium, Good or Perfect'. A visual scoring
      from 1 to 10 was used, with 10 for the perfect image, 4-10 as good and 1-4 as bad-medium. We
      searched for bleeding, angioembolisation, infection, reoperation, and thrombotic
      complications, especially pulmonary emboli.

      Statistical analysis and sample size calculation The mean sample size was calculated using
      the G Power 3.1 analysis program. The sample size was estimated at 90% power and 8%
      significance level, and it was determined that at least 20 patients per group were required
      to obtain a statistically significant value. Therefore, we included 25 patients in each group
      to prevent possible dropouts.

      The Statistical Package for the Social Sciences version 27 (SPSS IBM Corp., Armonk, NY, USA)
      program was used. The normality of the distribution of the variables was checked by the
      Shapiro-Wilk test and Q-Q plots. The one-way ANOVA test or Kruskal-Wallis test was used for
      the comparison of continuous variables. Comparison between groups was performed with Tukey
      posthoc analysis. Qualitative data are shown as mean ± standard deviation or median (IQR).
      Quantitative data are shown as mean ± standard deviation values. The data were analyzed at a
      95% confidence level.
    

Intervention name(s): Tranexamic acid
Intervention type(s): Drug
Intervention description(s): Tranexamic acid was administered in intravenous or locally within irrigation fluid
Other intervention name(s): Transamin®
Intervention MeSH terms: Tranexamic Acid
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Prevention
Keywords: blood loss; percutaneous nephrolithotomy; tranexamic acid; visual image quality