Biomedical subjects

Monish Aron

Publications and source records attributed to Monish Aron.

At least 19 recordsLinked to original sources

PubMed2006

Minimally invasive nephron-sparing surgery (MINSS) for renal tumours. Part II: probe ablative therapy.

OBJECTIVES: To review the evolution and current status of probe ablative methods of minimally invasive nephron-sparing surgery (MINSS) for renal tumours. METHODS: The English language literature of the past 10 yr was reviewed by using the National Library of Medicine database and the following keywords: chemoablation, cryoablation, high-intensity focused ultrasound, kidney, laser interstitial thermotherapy, microwave thermotherapy, nephron-sparing surgery, radiofrequency ablation, radiosurgery, renal, and tumour. Over 300 papers were identified, 50 of which were selected for this review on the basis of their contribution in advancing the field with regards to (1) evolution of concepts, (2) development and refinement of techniques, and (3) intermediate- and long-term clinical outcomes. RESULTS: Open partial nephrectomy is the reference standard for nephron-sparing surgery against which all MINSS techniques should be measured. Although the initial outcomes of cryoablation and radiofrequency ablation (RFA) are encouraging, long-term studies are necessary to confirm lasting efficacy. The optimal modality for tumour targeting, monitoring therapy, and follow-up remains to be determined. These ablative techniques should be reserved for carefully selected patients, the data should be prospectively accrued, and the long-term cancer cure rates should be compared with the reference standard. CONCLUSIONS: Promising long-term data are available for cryoablation. RFA is still considered developmental, and instances of incomplete cell kill, despite nonenhancement, are concerning. Other modalities are still experimental.

Catheter Ablation↗

PubMed2006

Minimally invasive nephron-sparing surgery (MINSS) for renal tumours part I: laparoscopic partial nephrectomy.

OBJECTIVES: To review the evolution and current status of extirpative methods (laparoscopic partial nephrectomy [LPN]) of minimally invasive nephron-sparing surgery (MINSS) for renal tumors. METHODS: The English language literature of the past 10 yr was reviewed by using the National Library of Medicine database and the following keywords: kidney, laparoscopic partial nephrectomy, minimally invasive, nephron-sparing surgery, renal, and tumor. Over 275 papers were identified. Of these, 55 papers were selected for this review on the basis of their contribution in advancing the field with regards to (1) evolution of concepts, (2) development and refinement of techniques, and (3) intermediate- and long-term clinical outcomes of LPN. RESULTS: Open partial nephrectomy (OPN) is the reference standard for nephron-sparing surgery against which all MINSS techniques should be measured. With available skills for time-sensitive intracorporeal suturing, LPN provides perioperative results and long-term oncologic and functional outcomes comparable to the reference standard, with significantly decreased patient morbidity. The initial 5-yr data of 50 patients has just become available, and shows overall and cancer-specific survival of 84% and 100%, respectively. As global experience with this technique increases, data need to be prospectively accrued, and long-term cancer cure rates should be compared with the reference standard. CONCLUSIONS: As of this writing, the technique and global acceptance of LPN is evolving, although it remains restricted by the complexity of laparoscopic renal reconstruction. In expert hands, cancer cure and renal function outcomes are similar to OPN.

Humans↗

PubMed2006

Laparoscopic assisted percutaneous nephrolithotomy (PCNL) in ectopic kidneys: two different techniques.

Two patients presented with calculi in ectopic kidneys. Complete clearance of calculi was achieved by laparoscopic assisted percutaneous nephrolithotomy (PCNL), by different but related techniques. In one patient with prior history of open pyelolithotomy, the anterior surface of the kidney was exposed by mobilizing the overlying sigmoid colon laparoscopically and the percutaneous tract was established into the desired calyx under combined laparoscopic and fluoroscopic control. In the second patient, the tract was established between the major mesenteric vessels without any mobilization of the bowel. Herein, we outline the nuances of these two related techniques, and the indications and contraindications for their use for laparoscopic assisted PCNL in ectopic kidneys.

Adult↗

PubMed2006

Radiation exposure to the patient and operating room personnel during percutaneous nephrolithotomy.

INTRODUCTION: The increased use of fluoroscopy during percutaneous nephrolithotomy (PCNL) places the urologist and operating room personnel at an occupational risk for measurable radiation exposure. We evaluated the degree of radiation exposure received by the patient and operating room personnel at our endourology facility during PCNL. PATIENTS AND METHOD: The incident radiation dose to the patient and the urologist during 50 consecutive PCNL procedures was monitored using lithium fluoride thermo-luminescent dosimeter chips (TLD chips). A hand held radiation survey meter was used to measure the radiation in air at different positions occupied by various operating room personnel. The approximate distances of the various personnel from the X-ray tube were also measured. RESULTS: PCNL was performed upon 35 males and 15 females. The average time for the procedure was 75 minutes (range: 30-150 min). The mean fluoroscopy screening time during the procedure was 6.04 min (range 1.8-12.16 min) with a mean fluoroscopy tube potential of 68 kVp and a mean tube current of 2.76 mA. The mean radiation exposure dose to the patient was 0.56 mSv (SD +/- 0.35), while the mean incident radiation exposure to the finger of the urologist was 0.28 mSv (SD +/- 0.13). CONCLUSION: The various operating room personnel are within safe radiation dose limits during PCNL. Efficient fluoroscopy further reduces the radiation scatter. All occupational personnel should 'achieve as low as reasonably achievable' dose by adhering to good practices.

Adolescent↗

PubMed2006

Cryotherapy: clinical end points and their experimental foundations.

More renal tumors are now being found at an early stage. Similarly, the treatment of patients with such small tumors is shifting away from radical nephrectomy toward nephron-sparing extirpative surgery or nonextirpative renal tumor ablation. Of the various techniques used for renal tumor ablation, cryotherapy is the most extensively studied and has the longest reported outcomes. In this article, we examine the experimental and clinical evolution of cryotherapy for small renal masses. A literature search was performed with the following key words: cryobiology, cryotherapy, cryoablation, tissue-ice interaction, temperature, monitoring, cryoinjury, renal function, blood pressure, and treatment end point. Articles that dealt with the experimental and clinical bases of current cryoablation principles and techniques were selected for review. Some recent studies representative of current clinical outcomes were also examined. Cryotherapy for the small renal tumor can be performed during open surgery, laparoscopically, or even percutaneously with use of a variety of probes and high-resolution imaging techniques to monitor therapy. In the clinical scenario, the ice ball is usually extended 1 cm beyond the visible tumor margin. Cryotherapy per se does not adversely affect renal function and blood pressure. Inadvertent cryoinjury to the collecting system rarely leads to urinary leakage. To date, only 6-month follow-up biopsy data are available. Absence of contrast enhancement on follow-up computed tomography or magnetic resonance imaging is considered oncologic success. For a sporadic unilateral renal tumor, 98% cancer-specific survival at 3 years has been reported. Cryotherapy has moved beyond the "experimental" stage, and initial outcomes are encouraging. The major criticism of this and other ablative techniques is the associated lack of histologic confirmation of complete tumor ablation. Long-term, diligently performed studies that provide detailed, meticulous, sequential 5-year radiologic and histologic data are necessary to confirm lasting efficacy. In addition, these data must be compared with those related to partial nephrectomy, which remains the reference standard.

Cryosurgery↗

PubMed2006

Reconstructive surgery for the management of genitourinary tuberculosis: a single center experience.

PURPOSE: We evaluated the role of surgery for genitourinary tuberculosis with special emphasis on reconstructive procedures. MATERIALS AND METHODS: Case records of 241 patients with genitourinary tuberculosis who underwent surgery at our center during a period of 17 years were reviewed. Clinical features, organ involvement, investigations, treatment and outcome of therapy were studied. RESULTS: There were 129 males and 112 females with a mean age of 34.6 years. The most common presentation was irritative voiding symptoms. Azotemia was seen in 54 (22.4%) cases. The most commonly involved organ was the kidney in 130 (53.94%) cases. Preoperative bacteriologic diagnosis was confirmed in 70 (29%) cases. All patients received antitubercular drug therapy for 9 months. A total of 248 procedures, including 33 endoscopic, 87 ablative and 128 reconstructive, were performed with some patients requiring more than 1 procedure. Early complications, which mainly involved the bowel, were seen in 19 (7.88%) cases. Bacteriologic cure was achieved in all culture positive cases. Renal functional parameters stabilized or improved in 44 of 54 patients (81.5%) in whom they were deranged at presentation. CONCLUSIONS: Genitourinary tuberculosis is common in developing countries. Diagnosis is often delayed because of late presentation and many patients present with cicatrization sequelae. A combination of antitubercular drug therapy and judicious surgery achieves satisfactory results in the majority of cases. With improved antitubercular drug therapy and experience with the use of bowel segments in the urinary tract, more reconstructive procedures are being performed with satisfactory outcomes. In patients who undergo reconstructive procedures, a rigorous and prolonged followup is necessary.

Adolescent↗

PubMed2006

Forgotten ureteral stents causing renal failure: multimodal endourologic treatment.

PURPOSE: To report our experience in managing nine patients with forgotten ureteral stents that resulted in chronic renal failure (CRF). PATIENTS AND METHODS: We reviewed our stent records from January 1994 to January 2004 to analyze cases of forgotten indwelling ureteral stents in solitary kidneys that had led to CRF (serum creatinine 4-14 mg/dL). These patients had normal renal function prior to the interventions at which stents were placed. They were subjected to multimodal endourologic management, including cystolithotripsy and ureteroscopic and percutaneous lithotripsy, to make them stent and stone free in a single operative session. RESULTS: The median dwell time of the retained stents was 39 months. Three patients were not aware of the stent, while six chose to ignore it. All patients underwent a temporizing percutaneous nephrostomy with an 8F pigtail catheter and were operated on 2 to 4 weeks later. All nine patients were rendered stone and stent free; however, one patient succumbed to septic complications 3 weeks after the operation. At last follow-up (6-56 months), two patients are on the transplant waiting list, while six are living with mild to moderate renal failure on conservative treatment. CONCLUSIONS: Chronic renal failure caused by encrusted stents in a functionally solitary kidney is a disastrous complication of forgotten stents. Prevention is, of course, ideal, but such cases are still seen despite increasing awareness. Temporizing percutaneous nephrostomy, renal support, and skilled endourologists are the cornerstones of management of such high-risk cases.

Adult↗

PubMed2006

Safety of supracostal punctures for percutaneous renal surgery.

AIM: Supracostal superior calyceal access has been shown to be the most suitable approach for staghorn calculi, calculi in the upper ureter and complex inferior calyceal calculi, as well as for antegrade endopyelotomy. However, many urologists hesitate in using this approach because of the potential for chest complications. The aim of this study was to analyze one institution's data regarding the safety and efficacy of this approach for percutaneous renal surgery. METHODS: A total of 890 renal units (762 patients) were treated with percutaneous renal surgery (849 percutaneous nephrolithotomy, 41 antegrade endopyelotomy) from July 1998 to July 2004. Supracostal access was obtained in 332 (37.3%) patients. The indications for a supracostal approach were ureteropelvic junction obstruction, staghorn and complex inferior calyceal calculi, and stones in the upper calyx or the upper ureter. All punctures were made by the urologist under C-arm fluoroscopic guidance in the prone position. RESULTS: The interspace between 11th and 12th rib was used in all except four patients in whom the puncture was made above the 11th rib. Eleven patients (3.31%) had a pleural breach presenting with fluid in the chest. Insertion of a chest tube was required in seven patients, while other four were managed conservatively. No patient had injury to the lung or other viscera. Hospital stay was not significantly prolonged as a result of the pleural breach in any patient. Except for staghorn calculi where multiple tracts were a necessity for maximal clearance, a single supracostal superior or middle posterior calyceal access served the purpose in 86% (177/205) of patients who underwent percutaneous surgery for renal or upper ureteric calculi. CONCLUSIONS: The supracostal superior calyceal approach was found to be effective as well as safe, with an acceptably low risk of chest complications.

Adult↗

PubMed2005

Antegrade endopyelotomy in pelvic kidney.

Antegrade endopyelotomy was performed in a patient with pelvic kidney. Nephrostomy tube had been placed in the patient during a previous open pyelolithotomy. The nephrostomy tract was used for establishing percutaneous access. The ureteropelvic junction (UPJ) was balloon dilated and incised laterally under vision. At 3-month-follow-up renal dynamic scan showed no evidence of UPJ obstruction.

Adult↗

PubMed2005

Laparoscopic partial nephrectomy versus laparoscopic cryoablation for the small renal tumor.

We sought to compare perioperative and short-term outcomes of laparoscopic partial nephrectomy versus laparoscopic cryoablation in patients with peripheral small renal tumors. Prospectively accrued data of patients with a small renal tumor (< or = 3 cm) undergoing laparoscopic partial nephrectomy (group 1, n = 153) or laparoscopic cryoablation (group 2, n = 78) were compared retrospectively. Patients undergoing laparoscopic partial nephrectomy were younger (mean age, 60.6 vs 65.6 years; P = 0.005), healthier (American Society of Anesthesiologists class 3/4 present in 46% vs 75%; P = 0.001), had a lower baseline serum creatinine (90.1 vs 106.0 micromol/L [1.02 vs 1.2 mg/dL]; P = 0.01), a larger tumor size (2.3 vs 2.1 cm; P = 0.02), and fewer cases of solitary kidneys (5% vs 23%; P = 0.000). Laparoscopic partial nephrectomy was associated with greater blood loss (211 vs 101 mL; P = 0.000) and a higher incidence of delayed complications after hospital discharge (16.3% vs 2.2%; P = 0.01) compared with cryoablation. Both groups were comparable with regard to operative time (P = 0.77), intraoperative complications (P = 0.1), postoperative complications (P = 0.55), hospital stay (P = 0.13), convalescence (P = 0.96), and postoperative serum creatinine (112.2 vs 123.7 micromol/L [1.27 vs 1.4 mg/dL]; P = 0.31). Local recurrence was detected over a mean follow-up time of 5.8 months in group 1 (0.6%) and 24.6 months in group 2 (3%). Although the technical simplicity, decreased blood loss, and somewhat lower complication rate are attractive features of renal cryotherapy, this must be balanced against the current lack of long-term follow-up data that are needed to confirm the oncologic adequacy of this developmental procedure. Laparoscopic partial nephrectomy, albeit a technically advanced procedure, duplicates established open principles and has therefore evolved to become our current minimally invasive nephron-sparing procedure of choice in the majority of patients with a small renal tumor.

Adolescent↗

PubMed2005

Incidental detection of purulent fluid in kidney at percutaneous nephrolithotomy for branched renal calculi.

BACKGROUND AND PURPOSE: Some patients undergoing percutaneous nephrolithotomy (PCNL) have purulent fluid in the pelvicaliceal system at the time of puncture, although preoperative features are not suggestive of infection. We report the management and outcome of 19 such patients. PATIENTS AND METHODS: Among the 639 patients who underwent PCNL at our center from July 2000 to October 2003, 19 had purulent fluid in the kidney at initial puncture. The preoperative findings, operative details, hospital course, and final outcome in these patients were analyzed. Twelve patients had stone removal at the first sitting (option 1), while seven had a nephrostomy tube placed initially with stone removal deferred for 3 to 7 days (option 2). RESULTS: With option 1, stones were cleared with one to three tracts in 45 to 120 minutes. Seven patients recovered smoothly, three had transient fever, while one had grade I and another had grade II sepsis. The purulent fluid grew E. coli in two cases and Proteus or Serratia in one case each and was sterile in eight. With option 2, stones were cleared using one to three tracts in 60 to 100 minutes. The fluid grew E. coli or Klebsiella in one case each and was sterile in five. Three patients had a smooth recovery, two had transient fever, one had grade I sepsis, and another had grade II sepsis. Risk factors for sepsis, irrespective of the option, were a recent history of febrile urinary-tract infection, borderline elevation of total leukocyte count, thick or foul pus as opposed to mere turbidity, the use of a single tube or tract or delayed creation of second tracts, and operating time >90 minutes. CONCLUSIONS: Despite normal preoperative urine and blood values, one may find purulence on puncture during PCNL, which is not always infected. If any one or more of the above risk factors is present, it is safer to drain the kidney initially, making sure that all blocked calices are drained, inserting multiple tubes if necessary.

Adult↗

PubMed2005

Hemiresection of the prostate: short-term randomized comparison with standard transurethral resection.

BACKGROUND AND PURPOSE: During transurethral resection of the prostate (TURP) for a very large and vascular gland in a medically compromised patient, there may arise the need for quick termination of the procedure because of medical problems that develop as a result of fluid absorption or bleeding if the surgery is prolonged. In such a situation, an alternative solution proposed by us is termination of the procedure after complete resection of one lateral lobe (and the median lobe, if present) of the prostate (hemiresection). PATIENTS AND METHODS: From January 1998 to December 2001, 161 consecutive symptomatic men with prostates >50 cc and an indication for prostatectomy were randomized to receive either a standard TURP (group 1; 80 patients) or prostatic hemiresection; i.e., complete resection of one lateral lobe and the median lobe, if present (group 2; 81 patients). The two groups were comparable in terms of age and prostate size. Preoperative and postoperative parameters were compared in the two groups using Student's t-test. RESULTS: Resected tissue weight was significantly greater in group 1, while the resection time and operative blood loss were significantly lower in group 2. The two groups had comparable improvement in symptom score and flow rate. CONCLUSIONS: Hemiresection of the prostate produces short-term functional results comparable to those of standard TURP in patients with prostates >50 cc, with shorter operative duration and significantly less bleeding. It is an acceptable surgical option in medically compromised patients with significant cardiac, pulmonary, or renal comorbidity.

Aged↗

PubMed2005

Percutaneous nephrolithotomy for complete staghorn calculi in preschool children.

BACKGROUND AND PURPOSE: To evaluate the safety and efficacy of percutaneous nephrolithotomy (PCNL) for the management of complete staghorn calculi in children <or=5 years old. PATIENTS AND METHODS: The charts of 19 preschool children (15 boys, 4 girls) aged 20 months to 5 years (mean 4.2 years) with complete staghorn calculi who underwent PCNL at our center over a 3-year period were reviewed. The mean stone burden was 972 mm2 (range 870-1210 mm2). All procedures were performed with the patient in the prone position after retrograde catheterization with a 5F ureteral catheter. Fluoroscopyguided punctures were made by the urologist followed by track dilation to 24F. A 19F sheathless nephroscope passed through an Amplatz sheath was used in all cases. Flexible nephroscopy was used as an adjunct where necessary. Postoperative stone clearance was documented by plain film or, for radiolucent calculi, ultrasonography. RESULTS: The majority of children (68%; N = 13) required two tracts, while five children (26%) required only one tract and one child required three. Complete clearance with PCNL monotherapy was achieved in 17 patients (89%), which increased to 94.7% with adjunctive shockwave lithotripsy. Stone analysis revealed struvite in 1, uric acid in 3, and calcium oxalate monohydrate in 15 patients. CONCLUSION: In preschool children, PCNL for complete staghorn calculi is a safe and effective method for maximal stone clearance.

Calcium↗

PubMed2005

Prospective, randomized comparison of transperitoneal versus retroperitoneal laparoscopic adrenalectomy.

PURPOSE: We report a prospective, randomized comparison of transperitoneal laparoscopic adrenalectomy (TLA) vs retroperitoneal laparoscopic adrenalectomy (RLA) for adrenal lesions with long-term followup. MATERIALS AND METHODS: Between December 1997 and November 1999, 57 consecutive eligible patients with surgical adrenal disease were prospectively randomized to undergo TLA (25) or RLA (32). Study exclusion criteria were patient age greater than 80 years, body mass index greater than 40, bilateral adrenalectomy and significant prior abdominal surgery in the quadrant of interest. Mean followup was 5.96 years in the 2 groups. RESULTS: The groups were matched in regard to patient age (p = 0.84), body mass index (p = 0.43), American Society of Anesthesiologists class (p = 0.81) and laterality (p = 0.12). Median adrenal mass size was 2.7 cm (range 1 to 9) in the TLA group and 2.6 cm (range 0.5 to 6) in the RLA group (p = 0.83). TLA was comparable to RLA in terms of operative time (130 vs 126.5 minutes, p = 0.64), estimated blood loss (p = 0.92), specimen weight (p = 0.81), analgesic requirements (p = 0.25), hospital stay (p = 0.56) and the complication rate (p = 0.58). One case per group was electively converted to open surgery. Pathology data on the intact extracted specimens were similar between the groups. Averaged convalescence was 4.7 weeks in the TLA group and 2.3 weeks in the RLA group (p = 0.02). During a mean followup of 6 years 2 patients in the TLA group had a late complication (port site hernia). Mortality occurred in 5 patients, including 1 with TLA and 4 with RLA, during the 6-year followup. CONCLUSIONS: For most benign adrenal lesions requiring surgery laparoscopic adrenalectomy can be performed safely and effectively by the transperitoneal or the retroperitoneal approach.

Adrenal Gland Neoplasms↗

PubMed2005

Potassium-titanyl-phosphate laser laparoscopic partial nephrectomy without hilar clamping in the survival calf model.

PURPOSE: Laparoscopic partial nephrectomy (LPN) with hilar clamping represents the various challenges associated with warm ischemia. We tested the feasibility, and acute and chronic outcomes of LPN using a potassium-titanyl-phosphate (KTP) laser without vascular hilar clamping in the survival calf model. MATERIALS AND METHODS: Six Jersey calves weighing 76 to 94 kg underwent a total of 12 staged bilateral transperitoneal laser LPNs of the mid/lower pole using an 80 W KTP laser, including left kidney chronic LPN with 1-month followup in 6 and right kidney acute LPN with immediate sacrifice in 6. Two techniques (ablative vaporization in 5 subjects and wedge resection in 7) were evaluated. Renal parenchymal resection and hemostasis were achieved only with the laser without any adjunctive hemostatic sutures or bioadhesives. Retrograde pyelography, renal arteriography and histological analyses were performed. RESULTS: All 12 procedures were successful performed laparoscopically without open conversion and 11 (92%) were done without hilar clamping. Mean total operative time was 2.9 hours (range 1.5 to 5) and mean blood loss was 119 cc (range 25 to 300). Mean lasing time was 56 minutes (range 20 to 100) with an average energy use of 54 kJ. Mean preoperative and postoperative hemoglobin (10.38 and 10.52 gm/dl) and serum creatinine (0.46 and 0.4 gm/dl, respectively) were similar. At 1-month followup there was no evidence of urinary leakage or arteriovenous fistula. CONCLUSIONS: This initial study of laparoscopic KTP laser partial nephrectomy without hilar clamping confirms its technical feasibility in most cases and good short-term outcomes. This success of laser LPN in the robust survival calf model with its human-sized kidney holds promise for future clinical application.

Animals↗

PubMed2005

Renal tumor ablation.

PURPOSE OF REVIEW: The management of small renal tumors is changing from radical nephrectomy to nephron-conserving surgery. The aim of this review is to discuss the currently prevailing methods used for nonextirpative renal tumor ablation. The studies published in English during 2004 to May 2005 have been reviewed in this article. RECENT FINDINGS: Of the various ablation techniques, cryotherapy and radiofrequency ablation are being increasingly applied clinically. They can be performed either laparoscopically or percutaneously using a combination of fine probes and high-resolution imaging techniques for focusing and monitoring the therapy. Noninvasive tumor ablation by high-intensity focused ultrasound, and other techniques, is still at an experimental stage. SUMMARY: Although the initial outcomes of cryoablation and radiofrequency ablation are encouraging, long-term studies are necessary to confirm their lasting efficacy. The optimal modality for tumor targeting, monitoring therapy, and follow-up remains to be determined. These ablative techniques should be reserved for carefully selected patients, the data should be prospectively accrued, and the results should be compared to that of the reference standard, open or laparoscopic partial nephrectomy.

Catheter Ablation↗

PubMed2005

Laparoscopy-assisted percutaneous nephrolithotomy (PCNL) in previously operated ectopic pelvic kidney.

A 35-year-old man with a left ectopic pelvic kidney and a prior history of open pyelolithotomy presented with recurrent multiple stones in the pelvic kidney. Complete clearance of calculi was achieved by laparoscopy-assisted PCNL (percutaneous nephrolithotomy). To the best of our knowledge this is the first report of laparoscopy-assisted PCNL in a previously operated ectopic pelvic kidney.

Adult↗

PubMed2005

Spectrum of stone composition: structural analysis of 1050 upper urinary tract calculi from northern India.

BACKGROUND: The purpose of the present paper was to study the spectrum of stone composition of upper urinary tract calculi by X-ray diffraction crystallography technique, in patients managed at All India Institute of Medical Sciences. METHODS: Between 30 April 1998 and 31 March 2003, a total of 1050 urinary calculi (900 renal, 150 ureteric) were analyzed. The stone fragments were collected after extracorporeal shock-wave lithotripsy, or retrieval by endoscopic (percutaneous nephrolithotomy, ureterorenoscopy), laparoscopic and various open surgical procedures. The structural analysis of the stones was done using X-ray diffraction crystallography. RESULTS: Four types of primary and three secondary X-ray diffraction patterns were obtained. The primary patterns were as follows. Pattern A, well organized crystalline structure; pattern B, moderately organized crystalline structure; pattern C, poorly organized crystalline structure; pattern D, very poorly organized crystalline structure. The three secondary patterns mainly highlighted the mixed variety of stones. These patterns were further analyzed and compared with standard X-ray diffraction (powder) photographs. Of the 1050 stones analyzed, 977 (93.04%) were calcium oxalate stones, out of which 80% were calcium oxalate monohydrate (COM) and 20% were calcium oxalate dihydrate (COD). Fifteen were struvite (1.42%) and 19 were apatite (1.80%). Ten were uric acid stones (0.95%) and the remaining 29 (2.76%) were mixed stones (COM + COD and calcium oxalate + uric acid, calcium oxalate + calcium phosphate, and calcium phosphate + magnesium ammonium phosphate). A total of 89.98% of staghorn stones were made of oxalates (COM/+COD) and only 4.02% were struvite. CONCLUSION: Urinary stone disease in the Indian population is different from that in Western countries, with a larger percentage of patients having calcium oxalate stones, predominantly COM. Also, the majority of staghorn stones (89.98%) were made of oxalates.

Adolescent↗