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Dean G Assimos

Publications and source records attributed to Dean G Assimos.

At least 37 records · Page 2Linked to original sources
PubMed2004

Quartz stones: spurious or iatrogenic?

We describe 2 cases of spurious quartz-containing calculi; the first patient-driven and the second iatrogenic. An iatrogenic etiology can occur after the use of holmium:yttrium-aluminum-garnet laser energy because the fiber tip is composed of quartz. To make the diagnosis of a spurious stone, a high degree of suspicion is essential. A quartz stone should prompt the diagnosis of a factitious disorder in the absence of the appropriate surgical history. Psychological counseling and/or referral to a pain management clinic should be considered in such cases.

Citric Acid↗
PubMed2004

Percutaneous nephrostolithotomy: predictors of length of stay.

PURPOSE: Percutaneous nephrostolithotomy (PNL) is commonly used to treat patients with complex renal calculi. A goal at our medical center is to discharge patients home less than 24 hours after PNL. We performed a study to determine factors that caused patients to be hospitalized longer than this period. MATERIAL AND METHODS: The available hospital records and office charts of 133 consecutive patients undergoing initial PNL at our institution between January 1, 1999 and December 31, 2000 were reviewed. All PNL procedures were performed by one of us using a (DGA) 1-stage technique. Mean patient age was 52 years (range 25 to 84). Of the subjects 85 were male and 48 were female. RESULTS: A total of 91 patients (68%) were discharged home less than 24 hours after surgery. The overall stone-free rate was 91%. Mean length of stay in the entire group was 1.97 days. Mean length of stay in those hospitalized longer than 24 hours was 4.12 days. Mean operative time, including time to obtain access, was 188.6 minutes. Multivariate analysis demonstrated that neurogenic bladder, endocrine comorbidity and perioperative complications were factors associated with a length of stay of greater than 24 hours. Univariate analysis demonstrated that preoperative urinary tract infection and infection related calculi were also associated with a length of stay of greater than 24 hours. CONCLUSIONS: The majority of patients undergoing PNL can be discharged home less than 24 hours after surgery. Patients with neurogenic bladder, those with endocrine comorbidity, those who sustain significant perioperative complications and those harboring stones associated with urinary tract infection or preoperative urinary tract infection are more likely to require longer hospitalization.

Adult↗
PubMed2003

Ileal ureter substitution: a contemporary series.

OBJECTIVES: To review our contemporary experience with ileal ureter reconstruction. Despite advancements in surgical technology and technical expertise, ureteral injuries continue to occur. These injuries can be extensive, and ileal ureter reconstruction may be necessary. METHODS: A total of 18 ileal ureter substitutions were performed in 16 adults (10 men and 6 women) by a single surgeon during a 6-year period. The mean patient age was 49.4 years (range 25 to 72). The mean follow-up was 18.6 months (range 7 to 59). All ileal ureter substitutions were performed in an isoperistaltic, refluxing fashion. Follow-up included clinical evaluation, nuclear renography, intravenous urography, and serum chemistry testing. RESULTS: Postoperative nuclear renography demonstrated no relative loss of function of the affected renal unit and no evidence of functional obstruction. An unobstructed state was also confirmed with intravenous urography. No statistically significant metabolic changes were found in any patient, as assessed by serum chemistry testing. None of the patients had evidence of new stone formation. Two patients developed an isolated, symptomatic urinary tract infection during follow-up, and one has had recurrent urinary tract infections, a problem that was present preoperatively. CONCLUSIONS: Ileal ureter substitution remains an effective treatment for patients with complex ureteral strictures or injuries. Stone activity does not appear to increase, and metabolic sequelae are uncommon in properly selected patients.

Adult↗
PubMed2003

Urologic manifestations of nonurologic disease urolithiasis.

Patients with nephrolithiasis may have coexistent diseases that play a causative role in stone formation. A stone event may be the initial manifestation of the disorder and the urologist may play a major diagnostic role. Regulation or correction of the disorder may eradicate or dramatically attenuate stone activity. In some patients, metabolic abnormalities persist, however, and the therapeutic strategies that were reviewed in this manuscript may need to be implemented. Stone disease may also be induced by drugs that are used to treat a number of disease processes. When this occurs, the drug will usually need to be discontinued and alternative therapy should be instituted.

Acidosis, Renal Tubular↗
PubMed2003

Computerized tomography guided access for percutaneous nephrostolithotomy.

PURPOSE: Access for percutaneous nephrostolithotomy (PNL) using conventional fluoroscopic guidance may carry an increased risk of damage to surrounding organs in patients with renal calculi and aberrant anatomy. In these situations cross-sectional anatomical imaging may facilitate safe percutaneous access. We describe our experience with computerized tomography (CT) guided percutaneous access for such patients undergoing PNL. MATERIALS AND METHODS: Between June 2000 and December 2001, 154 patients underwent PNL at our institution. Five of these patients (3%) required a total of 6 percutaneous access tracks under CT guidance. All patients in this group had anatomical abnormalities precluding standard access to the collecting system without risk to adjacent organs. These abnormalities included a retrorenal colon in 2 and a severely distorted body habitus due to spinal dysraphism in 3. RESULTS: Percutaneous access was achieved without complication in all cases. At subsequent PNL 5 of the 6 renal units (83%) were rendered completely stone-free. CONCLUSION: CT guided percutaneous access is infrequently required for PNL. However, there is a select group of patients with anatomical anomalies that may predictably require this procedure to facilitate safe and efficacious PNL.

Adult↗
PubMed2003

Percutaneous management of calculi within horseshoe kidneys.

PURPOSE: Percutaneous treatment of patients with calculi in a horseshoe kidney can be challenging due to the altered anatomical relationship in the retroperitoneum. Therefore, we performed a multi-institutional review to assess the safety and efficacy of this minimally invasive technique. MATERIALS AND METHODS: Of 37 patients identified with calculi in a horseshoe kidney at 3 institutions 24 (65%) underwent percutaneous nephrolithotripsy as primary treatment. Average patient age was 48.4 years and 75% of the patients were male. In 3 patients with staghorn calculi mean stone size as measured by computed digitized stone surface area was 448 mm2. Mean followup was 5.8 months. The stone-free rate, complication rate, need for secondary intervention and stone composition were evaluated. RESULTS: Renal access was obtained through an upper pole calix in 63% of the cases, a lower calix in 25% and a middle calix in 4%. Access location was not documented in 1 patient (4%). Of the 24 patients 21 (87.5%) were rendered stone-free after primary or second look procedures. Flexible nephroscopy was used in 84% of cases. Minor complications occurred in 4 patients (16.7%), whereas 3 (12.5%) experienced major complications, including significant bleeding necessitating early cessation, nephropleural fistula and pneumothorax. No deaths occurred as a result of this treatment choice. Stone analysis was available for 21 cases (87.5%). Calcium stones predominated (87.5%), followed by uric acid (9.5%) and struvite (4.8%). CONCLUSIONS: Percutaneous treatment of patients with renal calculi in a horseshoe kidney is technically challenging, usually requiring upper pole access and flexible nephroscopy due to the altered anatomical relationships of the fused renal units. The success rate based on stone-free results and a relatively low incidence of major complications suggest that this minimally invasive management option is an effective means of stone management in this complex patient population.

Adult↗
PubMed2003

Kidney and pancreas transplantation at Wake Forest University Baptist Medical Center.

More than 1,100 transplants have been performed at WFUBMC, including 60 pediatric transplants and 40 pancreas transplants. The one-year living donor kidney graft survival rate exceeds 90% and the 2 year deceased donor kidney graft survival rate exceeds 80%. The current active waiting list includes more than 300 candidates. Despite more transplants being performed, we continue to under-serve our referral area, which has among the highest rates of hypertension, diabetes, and end stage renal disease in the country. The AOTP has experienced a period of rapid growth over the past 2 years based upon sharing of zero HLA antigen-mismatched kidneys, use of ECD kidneys, liberalization of donor and recipient selection criteria, and the continued development of the pancreas transplant and laparoscopic donor nephrectomy programs. The pancreas transplant program will continue to grow as the waiting list enlarges and matures, with a 200% increase in activity expected within the next few years. The LDKT program will expand as more emphasis is placed on our pretransplant practice, including the more liberal application of laparoscopic donor nephrectomy, which has now become a standard procedure at our WFUBMC is involved in a number of clinical research projects studying new immunosuppressive agents and regimens. In this chapter, we have presented our recent experience with KTX in the elderly, ECD kidneys, alternate day Thymoglobulin administration, valganciclovir prophylaxis, SRL conversion using daclizumab bridge therapy, and pancreas transplantation with portal-enteric drainage. We plan to initiate a number of new protocols in the immediate future, including desensitization of the highly sensitized patient, ABO incompatible transplantation, transplantation of the HIV-positive patient, steroid withdrawal and avoidance regimens, living kidney donation from the anonymous altruistic donor, paired kidney exchanges from living donors, and islet transplantation. WFUBMC remains the most active donor hospital in North Carolina, and a non-heart beating donor protocol has been successfully initiated at our facility. Although much has been accomplished, a number of challenges remain. We look forward to building on our accomplishments, confronting the challenges, and achieving a level of excellence that could only be attained by mutual commitment from a dedicated, multidisciplinary team.

Academic Medical Centers↗
PubMed2003

Selecting Treatment for Distal Ureteral Calculi: Shock Wave Lithotripsy versus Ureteroscopy.

Shock wave lithotripsy (SWL) and ureteroscopy (URS) are both effective treatments for removal of distal ureteral calculi, associated with high success rates and limited morbidity. The American Urological Association Ureteral Stones Clinical Guidelines Panel has found both to be acceptable treatment options for patients, based on the stone-free results, morbidity, and retreatment rates for each respective therapy. However, costs and patient satisfaction or preference were not addressed, and the report was based on data derived from older endoscopic and lithotripsy technology. Each of these treatment options has valid advantages and disadvantages. Both modalities are reasonable treatment options for the majority of patients with distal ureteral calculi. Whereas SWL is less invasive, the high, immediate success rate with minimal morbidity and decreased cost makes URS a very valid competitor. The results of treating patients with larger stones favor URS.

Journal Article↗
PubMed2003

Drug-induced urinary calculi.

Urinary calculi may be induced by a number of medications used to treat a variety of conditions. These medications may lead to metabolic abnormalities that facilitate the formation of stones. Drugs that induce metabolic calculi include loop diuretics; carbonic anhydrase inhibitors; and laxatives, when abused. Correcting the metabolic abnormality may eliminate or dramatically attenuate stone activity. Urinary calculi can also be induced by medications when the drugs crystallize and become the primary component of the stones. In this case, urinary supersaturation of the agent may promote formation of the calculi. Drugs that induce calculi via this process include magnesium trisilicate; ciprofloxacin; sulfa medications; triamterene; indinavir; and ephedrine, alone or in combination with guaifenesin. When this situation occurs, discontinuation of the medication is usually necessary.

Journal Article↗
PubMed2002

Changing indications of open stone surgery.

OBJECTIVES: To compare the current role of open stone surgery at our institution to previously reported data. In 1989, the indications for open surgical treatment of urinary calculi at our institution were reviewed. In the intervening years, tremendous advances have been made in minimally invasive treatment of urinary calculi. METHODS: A retrospective evaluation of all patients undergoing procedures for the purpose of stone removal or fragmentation at Wake Forest University Baptist Medical Center between January 1, 1998 and May 31, 2001 was conducted. This was compared with data reported from our institution describing similar procedures in the first 19 months after introduction of the Dornier HM3 lithotriptor. RESULTS: Of 986 procedures performed for the purpose of stone removal or fragmentation between January 1, 1998 and May 31, 2001, 0.7% were open surgical procedures. Of these procedures, 85.8% were performed for anatomic indications. Patients referred from other institutions for evaluation after endoscopic treatment failure comprised the remaining 14.2% of this group. In the previously reported data, 893 procedures were performed for the treatment of urinary calculi, of which 4.1% were open operations. Of these patients, 48.6% underwent an open surgical procedure after unsuccessful endoscopic treatment of urinary calculi, and 48.7% of these patients underwent open surgery for anatomic indications. CONCLUSIONS: Open surgical stone removal remains a viable treatment option for select patients. Technologic advances and improved surgical skills have greatly reduced the number of patients requiring open surgery. This approach is mainly used for patients with complex calculous disease associated with anatomic abnormalities.

Adult↗