Infarction of middle third posterior cortex of kidney: a complication of extended pyelolithotomy, intra-operative electrohydraulic lithotripsy and extraction of calyceal stones under vision using stone basket and flexible cystoscope in a spinal cord injury patient – a case report

BACKGROUND: Spinal cord injury produces multiple systemic and metabolic alterations. A decrease in micro vascular blood flow to liver, spleen and muscle has been described following spinal cord injury. CASE PRESENTATION: We present a 46-year-old male patient with C-4 complete tetraplegia, who developed a large stag horn calculus with branches in upper, middle and lower calyces of left kidney. This patient underwent Gil-Vernet extended pyelolithotomy and required intra-operative electrohydraulic lithotripsy and retrieval of stones from upper, middle and lower calyces using flexible cystoscope and stone basket. Computed tomography, performed eighteen days after surgery, showed multiple areas of non-enhancing cortex posteriorly and in the upper pole, suggestive of focal infarction. Magnetic resonance imaging of left kidney confirmed the presence of an area of infarction in middle third of posterior cortex, but there was no evidence of trauma to posterior division of renal artery. Therefore, we postulate that compression of renal parenchyma by Gil-Vernet retractors during surgery, and firm pressure that was applied over the middle of kidney for prolonged periods while several attempts were being made to retrieve fragments of calculi from renal calyces, led to ischaemia and subsequently, infarction of mid-third posterior cortex of left kidney. CONCLUSION: This case illustrates importance of gentle handling of kidney during extended pyelolithotomy in order to prevent subtle renal trauma, which may be detected only by advanced imaging studies. Further, spinal cord physicians should take a pragmatic approach to management of stones located inside renal calyces. Both spinal cord injury patients and their physicians should remember that in our enthusiasm to achieve complete clearance of stones embedded deeply within renal calyces, we could produce irreversible injury to kidney, as indeed happened in this patient. Therefore, emphasis should be placed on prevention of struvite renal calculi by discarding indwelling urinary catheters and eliminating Proteus bacteriuria.