Hughes SF et al, 2015: A Pilot Study to Evaluate Haemostatic Function, following Shock Wave Lithotripsy (SWL) for the Treatment of Solitary Kidney Stones.
Hughes SF, Thomas-Wright SJ, Banwell J, Williams R, Moyes AJ, Mushtaq S, Abdulmajed M, Shergill I.
Department of Biological Sciences, University of Chester, Chester, United Kingdom.
North Wales & North West Urological Research Centre (NW2URC), University of Chester, Chester, United Kingdom.
Haematology Department, BCUHB Wrexham Maelor Hospital, Wrexham, North Wales, United Kingdom.
Clinical Biochemistry Department, BCUHB Wrexham Maelor Hospital, Wrexham, North Wales, United Kingdom.
Department of Clinical Sciences & Nutrition, University of Chester, Chester, United Kingdom.
Department of Urology, BCUHB Wrexham Maelor Hospital, Wrexham, North Wales, United Kingdom.
PURPOSE: The number of patients undergoing shock wave lithotripsy (SWL) in the UK for solitary unilateral kidney stones is increasing annually. The development of postoperative complications such as haematuria and sepsis following SWL is likely to increase. Comparing a range of biological markers with the aim of monitoring or predicting postoperative complications following SWL has not been extensively researched. The main purpose of this pilot-study was to test the hypothesis that SWL results in changes to haemostatic function. Subsequently, this pilot-study would form a sound basis to undertake future investigations involving larger cohorts.
METHODS: Twelve patients undergoing SWL for solitary unilateral kidney stones were recruited. From patients (8 male and 4 females) aged between 31-72 years (median-43 years), venous blood samples were collected pre-operatively (baseline), at 30, 120 and 240 minutes postoperatively. Specific haemostatic biomarkers [platelet counts, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, D-dimer, von Willebrand Factor (vWF), sE-selectin and plasma viscosity (PV)] were measured.
RESULTS: Platelet counts and fibrinogen concentration were significantly decreased following SWL (p = 0.027 and p = 0.014 respectively), while D-dimer and vWF levels significantly increased following SWL (p = 0.019 and p = 0.001 respectively). PT, APTT, sE-selectin and PV parameters were not significantly changed following SWL (p>0.05).
CONCLUSIONS: Changes to specific biomarkers such as plasma fibrinogen and vWF suggest that these represent a more clinically relevant assessment of the extent of haemostatic involvement following SWL. Analysis of such markers, in the future, may potentially provide valuable data on "normal" response after lithotripsy, and could be expanded to identify or predict those patients at risk of coagulopathy following SWL. The validation and reliability will be assessed through the assessment of larger cohorts.
PLoS One. 2015 May 4;10(5):e0125840. doi: 10.1371/journal.pone.0125840. eCollection 2015. FREE ARTICLE
That patients treated with SWL develop coagulopathy is to me new and surprising information. I have not had the impression that bleeding complications have had this explanation.
It is well recognized that tissue trauma might cause renal vascular damage and contusion/ small bleedings. But clinical symptoms or consequences of such minor lesions are unusual. Hematuria occurs in all patients as a consequence of stone disintegration with associated minor lesions to the mucosa; if no hematuria there is usually no stone disintegration.
The observed findings of reduced number of thrombocytes, decreased concentration of fibrinogen together with increased concentrations of von Willebrand factor and D-dimer are indeed interesting.
There seems to be need of further clinical evaluation of hemostatic effects of SWL. The question is if some of these variables should be analysed before and shortly after SWL?