Chronic pain in medullary sponge kidney: a rare and never described clinical presentation

Spinal cord stimulation for visceral pain associated with medullary sponge kidney

Chronic pain is a common reason for which people in the USA seek medical care. It is linked to opioid consumption, anxiety and a reduction in quality of life. Over the past 50 years, spinal cord stimulation (SCS) has evolved as a safe and efficacious treatment for chronic pain etiologies. The authors present the first known case of SCS for pain due to medullary sponge kidney disease. This report adds to the growing body of literature supporting the use of SCS for treating visceral organ pain, while also highlighting the utility of ventral lead placement for treating visceral pain. As SCS utilization increases, it is expected that there will be a decrease in opioid consumption, and this will help us contain the opioid epidemic.

Ultrasound Patterns and Disease Progression in Medullary Sponge Kidney in Adults

Our paper presents the ultrasound (US) patterns of a rare kidney disease-medullary sponge kidney (MSK)-that have not been described before in comparison with other causes of medullary hyperechogenicity and correlates them with the severity of the disease and prognosis. This is a clinical observational study of all US examinations in the Nephrology Department over a period of 6 years. The abdominal US focused on the kidneys was recorded. US characteristics of the medulla and cortex were analyzed. We found 10 patients with characteristic daisy flower (DF) kidneys. Positive diagnosis in association with other renal risk factors, prognosis, and evolution were evaluated. Two patterns of medullary hyperechogenicity were found and were correlated with disease severity and kidney function. The first pattern is a homogenous echogenicity of the medulla described as a "daisy-like" appearance. The second pattern: calcifications associated with medullar echogenicity, stone production, nephrocalcinosis, and impaired kidney function: "atypical daisy-like." Medullary hyperechogenicity can have more US patterns. In MSK, if the medullary echogenicity is homogenous the evolution is benign, whereas the second, inhomogeneous pattern, has a variable clinical presentation with nephrocalcinosis and the outcome is more severe, leading to chronic kidney disease and impairing the quality of life.

Opioid Free Ureteroscopy: What is the True Failure Rate?

OBJECTIVE

To determine the true failure rate of opioid free ureteroscopy (OF-URS) and rates of new-persistent opioid use utilizing a national prescription drug monitoring program.

MATERIAL AND METHODS

We identified 239 patients utilizing our retrospective stone database who underwent OF-URS from Februrary 2018-March 2020. In Feb 2018, we initiated a OF-URS pathway (diclofenac, tamsulosin, acetaminophen, pyridium and oxybutynin). Patients who had a contraindication to NSAIDs were excluded from primary analyses. A prescription drug monitoring program was then utilized to determine the number of patients who failed OF-URS (defined as receipt of an opioid within 31 days of surgery) as well as rates of new-persistent opioid use (defined as receipt of opioid 91-180 days after surgery). All statistical analyses were performed using SAS 9.4. Tests were 2-sided and statistical significance was set at P<0.05.

RESULTS

We found a OF-URS failure rate of 16.6% and 14.0% in the total and opioid naïve cohorts, respectively. Rates of new-persistent opioid use were 0.9% and 1.2%, respectively (lower than published expected rate of ~6% after URS with postoperative opioids). 91% of patients obtained opioid from alternative sources. Uni/multivariate analyses were performed for both cohorts. In the total cohort, benzodiazepine users had a lower risk of OF-URS failure on multivariate analysis. No variables were associated with OF-URS failure in the opioid naïve cohort.

CONCLUSION

The true failure rate of OF-URS is higher than previously thought at 16.6% and 14.0%. However, efforts to reduce opioid prescriptions with OF-URS pathways have successfully reduced new-persistent opioid use.

Medullary Sponge Kidney: Current Perspectives

Medullary Sponge Kidney (MSK) disease is a rare congenital malformation of the distal nephron where cystic dilatation is appreciable in the collecting ducts and renal papillae. Most cases of the malformation are thought to arise from a malfunction within neurotrophic factor and tyrosine kinase interactions. Presentation and prognosis are usually indolent; however, they include urinary tract infections (UTI), nephrolithiasis and nephrocalcinosis, distal renal tubular acidosis (dRTA) and hypocitraturia. With an insidious and asymptomatic onset, MSK is a difficult renal manifestation to both diagnose and treat. Difficulty diagnosing MSK today arises from clinical settings deviating from the usage of contrast methods when assessing the urogenital tract. Many healthcare standards for kidney disorders center diagnosis around imaging techniques rather than contrast methods. This ultimately leads to a decrease in the total number of confirmed cases of MSK. Though intra-venous urogram (IVU) remains as the current gold standard to diagnose MSK, other methods such as endoscopy and Multi-detector computed tomography (MDCT) are being put into place. Endoscopic examination and renal biopsy may allow definitive diagnosis; however, such invasive methods may be considered excessive. Moving forward, differential diagnoses for MSK can be made more precisely when patients present with other renal manifestations, especially in groups at risk. These groups include patients between the age of 20 and 30, patients with other renal malformations, high sodium diet patients, hyperparathyroid patients, and patients with family history of MSK. Basic treatment is aimed at controlling stone formation by stabilizing urinary pH. Treatment for patients, especially those prone to forming stones, includes the application of potassium citrate compounds, prophylactic water and diet control, surgical intervention or lithotripsy for removal of symptomatic kidney stones.

Living kidney donation from people at risk of nephrolithiasis, with a focus on the genetic forms

Deciding whether to accept a donor with nephrolithiasis is a multifaceted task because of the challenge of finding enough suitable donors while at the same time ensuring the safety of both donors and recipients. Until not long ago, donors with a history of renal stones or with stones emerging during screening on imaging were not considered ideal, but recent guidelines have adopted less stringent criteria for potential donors at risk of stones. This review goes through the problems that need to be approached to arrive at a wise clinical decision, balancing the safety of donors and recipients with the need to expand the organ pool. The risk of declining renal function and worsening stone formation is examined. Documents (consensus statements, guidelines, etc.) on this issue released by the most important medical societies and organizations are discussed and compared. Specific problems of living kidney donation associated with certain systemic (chronic hypercalcemia due to CYP24A1 gene mutations, primary hyperoxaluria, APRT deficiency) and renal (medullary sponge kidney, cystinuria, distal renal tubular acidosis, Dent's disease, Bartter syndrome, familial hypomagnesemia with hypercalciuria and nephrocalcinosis) Mendelian disorders that cause nephrolithiasis are also addressed.