Renal stones treatment in Spinal-Cord–Injured patients
The risk of upper tract stone disease in patients with SCI is significantly higher than the general population. Risk for urolithiasis in the general population is estimated at 12% for men and 6% for women with annual incidence rates between 0.36 to 1.22/1000 person years. A large series study found the incidence rate after the first year post SCI was 8/ 1000 person-years with an incidence of urinary stones up to 38%.
The incidence of renal calculi appears to peak during the period immediately after SCI. This early risk of stone formation is hypothesized to be a result of a significantly increased calcium excretion because immobilization and loss of calcium from the lower extremity skeleton.
In addition bladder neurologic dysfunction as detrusor hypocompliance, detrusor-sphincter dyssynergia and detrusor overactivity can lead to increase urinary tract infection (UTI), stone disease, bladder cancer, autonomic dysreflexia, and renal dysfunction.
In these patients urinary stones are frequently composed by struvite and calcium phosphate rarely by calcium oxalate.
Higher risk of complication in these patients is related to urinary tract infections by Proteus, Ureoplasma o Klebsiella; patients positioning obliged by musculoskeletal spasticity and comorbidity.
This study reports the experience of a single unit and the objective was to evaluate incidence of complications in patients with renal stones and SCI treated with RIRS or PCNL compared to general population.
Materials and Methods
A retrospective chart review of patients with spinal neuropathy who underwent PCNL and RIRS was undertaken. The charts of 9 patients with spinal neuropathy who underwent PCNL and RIRS for renal stones in our institution between 2013 and August 2016 were reviewed.
All patients who underwent contrast URO TC and were evaluated to identify the preoperative stone characteristics. Stone size was determined by measuring the greatest length of the stone on CT. In case of a kidney with multiple stones the stone burden of that kidney was determined by adding the sizes of all the stones.
A urine culture was obtained preoperatively in all patients. If patients had bacteriuria, they were treated with a specific antibiotic preoperatively.
Age, operative time, stone side and characteristic, stone free rate and complications were also recorded.
All procedures were performed by a single surgeon with the experience of more than 50 cases for each treatment.
The percutaneous access was performed by the urologist. The renal puncture was done under fluoroscopic and ultrasonography control. The telescopic dilation in prone position was used under fluoroscopic control through the calix and when a supine procedure was done a pneumatic balloon for dilation was used. A 24 F Amplatz sheath was positioned, and an ultrasonic or pneumatic lithotripter used for lithotripsy. Nefroscope of 22 ch with continuous flow irrigation was used. The operative time was evaluated from the puncture to removal of Amplatz sheath. In RIRS treatment a flexible URS 7.5 ch with holmium laser lithotripsy was used. After a urinary stent DJ was inserted and was removed within two weeks. Only patients with no stones or a single stone size < 4 mm on postoperative ultrasound and KUB after 3 month was declared stone free
A total of 9 patients 6 male and 3 female, age 23-58 years (average 42) were treated and a total of 10 procedures were performed. A quadriplegia was present in 2 cases, paraplegia in 2, Multiple sclerosis in 4 and only 1 patient had a spastic quadriplegia
In one patient a percutaneous treatment and the next RIRS was performed. In 5 patients kidney stones were located in the left kidney and in 4 in the right kidney.
Stone free rate was higher in PCNL group.
Urinary stones were located in 1 case in the renal pelvis, in 6 cases in the renal pelvis and in the lower calyx, in 1 case in the renal pelvis and middle calyx and in 1 case the stone was located in the pelvis and in two calix (middle and lower). In 3 patients hydronefrosys was also present.
In 6 cases urine cultural examination was positive and the patients were treated with specific antibiotic therapy the others with third generation cephalosporine or fluorchinolone preoperative prophylaxis.
Stone diameter was included between 1.4 and 4.6 cm (average 2.6 cm); in 6 cases a PCNL and in 4 cases RIRS were respectively performed.
Average operative time was 54.1 min in RIRS group and 40.3 min in PCNL group.
Only two patients were considered no stone free and one of them underwent RIRS.
Analysis of complication showed an incidence of postoperative infection in 2 patients treated with RIRS and in one of them a serious septic event with a perirenal ematoma was recorded (Clavien IVb). No respiratory failure after awakening was reported.
In PCNL group no septic events were present but a serious post-operative bleeding was recorded. The patient was treated with selective embolization and no blood transfusions were needed (Clavien IIIa). He was discharged in 5 days.
Time of hospitalization was comparable to patients without SCI with a single exception of one patient with a serious complication that was kept for a long period in intensive care.
The management of upper tract stones is more difficult in patients with SCI than in the general population. The higher incidence of bacteriuria and infection stones increases the risk of sepsis either with the presentation of the stone or as a result of treatment of the stone.
Treatment of sepsis is complicated by the high rate of multidrug-resistant bacteria within this population.
Anyway only early identification and treatment of urolithiasis in SCI patients will aid in preserving renal function and minimizing associated complications.
In our short series no septic complications were reported after PCNL and in this group stone free rate was higher than in RIRS group.
Post operative fever and several sepsis were reported in two of four cases treated with RIRS.
Not many studies about endoscopic treatment of kidney stones in patients with SCI are present. Some reports consider flexible ureteroscopy and laser lithotripsy as an effective treatment modality for SCI patients with upper urinary tract calculi with an incidence of complication of 22%. Nabbout et al. in a series of 46 PCNL in 26 renal unit report an incidence of complication of 14.3% patients, necessitating admission to the intensive care unit postoperatively.
Percutaneous treatment seems to be more suitable in patient with renal stones and SCI.
Surgical management of urolithiasis in patients with SCI should be performed in high-volume units in light of the technical challenges and higher rate of perioperative complications.
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