Search PubMed⌕ Search

Biomedical subjects

T W Jarrett

Publications and source records attributed to T W Jarrett.

At least 37 records · Page 2Linked to original sources
PubMed2000

Plain abdominal x-ray versus computerized tomography screening: sensitivity for stone localization after nonenhanced spiral computerized tomography.

PURPOSE: Urolithiasis followup with plain abdominal x-ray requires adequate visualization of the calculus on the initial x-ray or computerized tomography (CT) study. We compared the sensitivity of plain abdominal x-ray versus CT for stone localization after positive nonenhanced spiral CT. MATERIALS AND METHODS: We evaluated 46 consecutive nonenhanced spiral CT studies positive for upper urinary tract lithiasis for which concurrent plain abdominal x-rays were available. X-ray and CT studies were compared for the ability to visualize retrospectively a stone given its location by CT. A consensus of 1 radiologist and 3 urologists was reached in each case. Cross-sectional stone size and maximum length were measured on plain abdominal x-ray. RESULTS: Plain abdominal x-ray and scout CT had 48% (22 of 46 cases) and 17% (8 of 46) sensitivity, respectively, for detecting the index stone (p <0.00004). Of the 39 stones overall visualized on plain abdominal x-ray only 19 (49%) were visualized on scout CT. Mean cross-sectional area and length of the stones on scout CT were 0.34 cm.2 (approximately 6 x 5.5 mm.) and 6. 5 mm., respectively, while the average size of those missed was 0.11 cm.2 (approximately 4 x 3 mm.) and 3.6 mm. The mean size differences in the groups were highly significant (p <0.0009). CONCLUSIONS: Plain abdominal x-ray is more sensitive than scout CT for detecting radiopaque nephrolithiasis. Of the stones visible on plain abdominal x-ray 51% were not seen on CT. To facilitate outpatient clinic followup of patients with calculi plain abdominal x-ray should be performed when a stone is not clearly visible on scout CT.

Humans↗
PubMed2000

Endovascular gastrointestinal stapler device malfunction during laparoscopic nephrectomy: early recognition and management.

PURPOSE: Controlled ligation and division of the renal hilum are critical steps during any nephrectomy procedure. The use of the endovascular gastrointestinal anastomosis (GIA) stapling device for control of the renal vessels during laparoscopic nephrectomy has become standard practice. However, malfunction can lead to serious consequences which require emergency conversion to an open procedure. We report our experience with GIA malfunction during laparoscopic nephrectomy. MATERIALS AND METHODS: From July 1993 to September 1999, 565 patients underwent laparoscopic nephrectomy at 2 institutions for benign and malignant diseases, and for live renal donation. Retrospective chart reviews and primary surgeon interviews were conducted to determine etiology of failure, intraoperative management and possible future prevention. RESULTS: Malfunction occurred in 10 cases (1.7%). In 8 cases the renal vein was involved and malfunctions affected the renal artery in 2. The estimated blood loss ranged from 200 to 1,200 cc. Open conversions were necessary in 2 cases (20%). The etiology of the failure included primary instrument failure in 3 cases and preventable causes in 7. Open surgery was required in 2 patients and laparoscopic management was possible in 8. CONCLUSIONS: The endovascular GIA stapler is useful in performing laparoscopic nephrectomy. However, malfunctions may occur, and can be associated with significant blood loss and subsequent need for conversion to an open procedure. The majority of errors could be avoided with careful application and recognition. Many failures, especially when recognized before release of the device, can be managed without conversion to an open procedure.

Anastomosis, Surgical↗
PubMed1999

13-year survival comparison of percutaneous and open nephroureterectomy approaches for management of transitional cell carcinoma of renal collecting system: equivalent outcomes.

BACKGROUND AND OBJECTIVE: Transitional cell carcinoma (TCC) of the renal collecting system traditionally has been managed by open nephroureterectomy with en bloc resection of a bladder cuff. However, for a select patient population with a solitary kidney or bilateral disease, the morbidity and mortality associated with chronic renal insufficiency and dialysis is deterring. In these situations, a more conservative approach such as antegrade percutaneous resection should be considered. The long-term disease-free outcome of percutaneous management in comparison with open nephroureterectomy has not been previously reported. We evaluated our experience with two surgical approaches to treat upper tract TCC: percutaneous resection and nephroureterectomy/nephrectomy to assess the clinical efficacy of these surgical modalities. PATIENTS AND METHODS: We retrospectively identified 162 patients who had clinically localized TCC of the upper urinary tract. Records were reviewed to identify those with 13-year follow-up (N = 110) in respect to tumor grade, stage, disease-free status, length of cancer-specific survival, and overall survival. Statistical analysis of the results of open nephroureterectomy/nephrectomy (N = 60) and percutaneous resection (N = 50) was performed using Kaplan-Meier survival curves and Student's t-test. RESULTS: All patients had disease in clinical stage Ta through T3. During a mean follow-up of 46.6 (range 6-150) months, grade 1 disease demonstrated little invasive potential. Of the disease-specific deaths, 60% (17/26) were of patients with grade 3 lesions, with a mean cancer survival period of 15.2 months after the initial procedure. Disease-specific survival rates after open and percutaneous approaches for grade 2 disease were 53.8 and 53.3 months, respectively (P > 0.05). CONCLUSIONS: Tumor grade appeared to be the most important prognostic indicator in patients with renal TCC regardless of the surgical approach. Grade 3 tumors were more aggressive, presenting in an advanced stage with invasion, and recurrences were usually associated with metastasis. In this population, nephroureterectomy is warranted if the patient is a surgical candidate. The percutaneous option for grade 1 or 2 disease may be extended beyond the population with solitary kidneys and a risk of chronic renal failure to be offered to healthy individuals with normal contralateral kidneys who are willing to abide by a strict and lengthy follow-up.

Adult↗
PubMed1999

Familial calcium stone disease: TaqI polymorphism and the vitamin D receptor.

BACKGROUND AND OBJECTIVE: Calcium nephrolithiasis has a strong familial component. However, to date, no specific genetic abnormality has been identified. Allelic variation in the vitamin D receptor (VDR) gene has been suggested as a partial explanation of differential calcium absorption or excretion in these patients. Polymorphism of this gene has been associated with altered vitamin D activity and has been implicated in osteoporosis and prostate cancer. We propose that a similar association may be found between familial hypercalciuric stone disease and the VDR. SUBJECTS AND METHODS: Genomic DNA was isolated from 37 controls and 19 patients with hypercalciuria (> 250 mg/24 hours) and a family history of nephrolithiasis. A 740-basepair segment of the VDR gene was amplified by polymerase chain reaction, digested with TaqI endonuclease, and resolved by gel electrophoresis. Alleles were classified as "T" if only one TaqI site was present and "t" if two were present. A simplified strength of family history score (FHS) was computed by adding 2 and 1 points, respectively, for each first- and second-degree relative affected by stone disease. RESULTS: No difference in allelic or genotypic frequencies between the study and control groups was present. In the stone group, a significant association was found between the strength of the family history and the TT genotype. Patients with this genotype had an average FHS of 4.0, whereas the mean FHS for the Tt and tt genotypes was 2.0 and 1.8, respectively (P < 0.05). Nonsignificant trends of the TT genotype toward a higher number of stone episodes (19 v 13 and 3) and higher 24-hour urine calcium excretion (408 v 297 and 353 mg) were also noted in the study group. CONCLUSION: The results suggest that the TT genotype is associated with more aggressive stone disease, both within families and with respect to recurrence. Quantifying the risk of calcium stone disease through DNA markers has potential application in determining the risk of a patient's family members for nephrolithiasis or a patient's risk of recurrence. This information may have therapeutic implications with regard to the rigor of medical therapy and frequency of follow-up.

Alleles↗
PubMed1999

Use of rigid hysteroscope for extraction of foreign bodies embedded in lower urinary tract.

PURPOSE: To introduce the use of the 20F rigid hysteroscope in urologic procedures. MATERIALS AND METHODS: The 20F hysteroscope was used to remove deeply embedded foreign bodies from the lower urinary tract of three patients in whom previous attempts with standard cystoscopic equipment were unsuccessful. RESULTS: In all three cases, the hysteroscope easily passed into the urethra and with the use of rigid instruments was able to remove the foreign bodies without complication. CONCLUSION: Situations may arise when the removal of embedded foreign bodies is not possible with standard cystoscopic equipment. The hysteroscope, which is available in most operating rooms, was able to extirpate even deeply embedded foreign bodies.

Aged↗
PubMed1999

Retroperitoneal access for transperitoneal laparoscopy in patients at high risk for intra-abdominal scarring.

BACKGROUND AND PURPOSE: Adhesions from prior extensive open abdominal surgery can make initial transperitoneal access for laparoscopy hazardous. An alternative to open port placement is a retroperitoneal approach to the peritoneal cavity. We describe our retroperitoneal access for transperitoneal laparoscopy and evaluate the success of the subsequent laparoscopic procedure. PATIENTS AND METHODS: Eight patients with a history of abdominal surgery have undergone retroperitoneal access to the peritoneum prior to a laparoscopic urologic procedure. With the patient in a lateral decubitus position, the retroperitoneum is entered with a 10-mm Visiport device (US Surgical Corp., Norwalk, CT) along the posterior axillary line. A working space is bluntly created, the peritoneum identified anterior to the colon, and the endoscope passed through a peritoneotomy. The abdomen is then inspected, transperitoneal ports are strategically placed under direct vision, and the intended procedure is commenced. RESULTS: In all cases, retroperitoneal access to the peritoneum and subsequent trocar placement was successful. In five cases, the intended procedure was completed laparoscopically. In a case of bilateral ureterolysis, one side was completed laparoscopically; however, the other required open conversion. In two nephrectomies for xanthogranulomatous pyelonephritis (XGP), open conversion was necessary because of fibrosis. CONCLUSION: Retroperitoneal access to the peritoneal cavity permits safe and effective port placement when previous abdominal surgery makes initial transabdominal access difficult. However, despite successful access, in patients at risk for extensive perinephric fibrosis (e.g., XGP), a high incidence of open conversion may be expected.

Abdomen↗
PubMed1999

The EndoHand: comparison with standard laparoscopic instrumentation.

Laparoscopic instrumentation is constantly being refined in an attempt to achieve the proficiency, flexibility, and tactile feedback that would be available if the human hand were small enough to be used in laparoscopic surgery. The EndoHand (DAUM GmbH, Schwerin, Germany) is a novel laparoscopic three-fingered hand developed as an advancement over standard laparoscopic tools. Grasping and manipulation ability, dexterity, and tactile feedback were compared with those of current laparoscopic instrumentation. Experiments included measurement of achievable angles of approach to a fixed point behind a 2-cm-tall obstruction, completion time and error rates during a pelvic trainer dexterity task, and tactile feedback using a device invented to simulate tissue resistance. Subjectively, the EndoHand was able to pick up a range of objects similar to those graspable by a Babcock clamp. More complex types of manipulation were possible with the EndoHand because of its wrist joint. The range of approach angles to the fixed point was 35 degrees to 90 degrees with the EndoHand and 70 degrees to 90 degrees with the straight instruments. The dexterity of the EndoHand was significantly less than that of the other two instruments, as measured by time (P = 0.0002) and errors (P = 0.02). Standard instruments were also more accurate in the tactile feedback trials (P = 0.02). The EndoHand is a prototype of a unique new generation of laparoscopic instruments. Although it falls short in both dexterity and tactile feedback, significant promise is shown in its ability to perform sophisticated manipulation of objects and its flexibility to work at a larger range of angles to the target tissue. The EndoHand may be most useful on the nondominant hand of the surgeon to assist with positioning and holding tissue in a specific orientation. Clinical trials will determine its eventual role in laparoscopic surgery.

Confidence Intervals↗
PubMed1999

Laparoscopic testicular denervation for chronic orchalgia.

PURPOSE: No specific cause is identified in most cases of chronic orchialgia. Nonsurgical therapies, including management at a chronic pain clinic, are generally recommended. Only when multiple conservative measures fail are patients offered surgical intervention, such as orchiectomy. We evaluate laparoscopic testicular denervation as an organ preserving and minimally invasive surgical alternative. MATERIALS AND METHODS: Since 1993, 9 patients with chronic orchialgia have undergone transperitoneal laparoscopic testicular denervation after nonsurgical modalities failed. Using 1, 10 mm. and 1 or 2, 5 mm. ports, the gonadal vessels were isolated circumferentially and divided cephalad to the vas deferens and its vasculature. Preoperative treatment modalities, morbidity and outcome were documented. A cord block provided temporary relief in all 9 patients. Analog scales were used to assess long-term pain relief (0 no pain to 100 worst pain) and activity levels (0 bedrest to 100 no restrictions). RESULTS: Average symptom duration before laparoscopic testicular denervation was 4.1 years. Of 9 patients 8 had undergone prior scrotal surgery. Failed nonsurgical modalities included anti-inflammatory drugs in 7 patients, antibiotics in 6, pain clinic consultations in 4 and antidepressant medications in 2. Mean pain score decreased from 69.4 (range 35 to 90) preoperatively to 30.6 at a mean followup of 25.1 months. Excluding the 2 cases that had no pain relief (less than 10-point reduction), average pain score decreased from 69 to 19 postoperatively (mean reduction 71%). Activity levels improved in all cases. There were no significant complications, including testis atrophy. One patient who had no pain relief underwent subsequent hydrocelectomy for pain, which also failed. CONCLUSIONS: Laparoscopic testicular denervation can provide significant long-term pain relief and appears to be a reasonable alternative in select cases with chronic orchialgia refractory to medical therapy. Larger series and prospective evaluations are necessary.

Adult↗
PubMed1999

Clinical decision making using teleradiology in urology.

OBJECTIVE: Using a personal computer-based teleradiology system, we compared accuracy, confidence, and diagnostic ability in the interpretation of digitized radiographs to determine if teleradiology-imported studies convey sufficient information to make relevant clinical decisions involving urology. Variables of diagnostic accuracy, confidence, image quality, interpretation, and the impact of clinical decisions made after viewing digitized radiographs were compared with those of original radiographs. MATERIALS AND METHODS: We evaluated 956 radiographs that included 94 IV pyelograms, four voiding cystourethrograms, and two nephrostograms. The radiographs were digitized and transferred over an Ethernet network to a remote personal computer-based viewing station. The digitized images were viewed by urologists and graded according to confidence in making a diagnosis, image quality, diagnostic difficulty, clinical management based on the image itself, and brief patient history. The hard-copy radiographs were then interpreted immediately afterward, and diagnostic decisions were reassessed. All analog radiographs were reviewed by an attending radiologist. RESULTS: Ninety-seven percent of the decisions made from the digitized radiographs did not change after reviewing conventional radiographs of the same case. When comparing the variables of clinical confidence, quality of the film on the teleradiology system versus analog films, and diagnostic difficulty, we found no statistical difference (p > .05) between the two techniques. Overall accuracy in interpreting the digitized images on the teleradiology system was 88% by urologists compared with that of the attending radiologist's interpretation of the analog radiographs. However, urologists detected findings on five (5%) analog radiographs that had been previously unreported by the radiologist. CONCLUSION: Viewing radiographs transmitted to a personal computer-based viewing station is an appropriate means of reviewing films with sufficient quality on which to base clinical decisions. Our focus was whether decisions made after viewing the transmitted radiographs would change after viewing the hard-copy images of the same case. In 97% of the cases, the decision did not change. In those cases in which management was altered, recommendation of further imaging studies was the most common factor.

Decision Making↗
PubMed1998

The "mini-perc" technique: a less invasive alternative to percutaneous nephrolithotomy.

The disadvantages of standard percutaneous nephrolithotomy (PCNL) as compared with ureteroscopy or extracorporeal shock-wave lithotripsy include increased blood loss, greater pain, and longer hospital stay. A 13-Fr "mini-perc" technique using a ureteroscopy sheath for PCNL was developed in an attempt to address these drawbacks. Nine "mini-percs" have been performed in patients aged 40-73 years with stone burdens of < or = 2 cm2. On average, patients had 1.4 stones with a cross-sectional area of 1.5 cm2. The mean total procedure time, estimated blood loss, and hematocrit decrease were 176 min, 83 ml, and 6.6%, respectively. On average, patients used 14 mg of parenteral morphine and stayed 1.7 days in the hospital. There was no procedure-related complication or transfusion. Eight of nine kidneys (89%) were stone-free on early follow-up at a mean of 3.8 weeks. As compared with standard PCNL, the "mini-perc" technique has similar early success rates in selected patients and may offer advantages with respect to hemorrhage, postoperative pain, and shortened hospital stays.

Adult↗
PubMed1997

Protease inhibitor-induced urolithiasis.

OBJECTIVES: To describe protease inhibitor-induced urinary stone disease in patients with human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) who are taking indinavir sulfate (Crixivan), a protease inhibitor, for the treatment of AIDS. METHODS: Patients with HIV/AIDS and symptomatic renal colic temporally related to the initiation of indinavir sulfate therapy were prospectively identified. Seven patients (mean age 42 years; all men) with HIV and renal colic who were taking indinavir were identified. Retrospective chart reviews and patient interviews were performed. RESULTS: Indinavir therapy averaged 5.7 months prior to presentation with renal colic. All patients had microscopic hematuria. One patient presented with acute azotemia from bilateral urinary obstruction. Six patients had no history of urinary stones prior to initiating indinavir. The median number of symptomatic urinary stone episodes after initiating indinavir was two stones per patient. All patients had moderate- to high-grade urinary obstruction from radiolucent calculi. Abdominal computed tomography (CT) demonstrated hydronephrosis without urinary calcifications. Three patients spontaneously passed stones and 4 required intervention. Yellow debris and/or brown matrix-like material was seen endoscopically. Stone analysis revealed pure protease inhibitor. Six patients (86%) eventually discontinued protease inhibitor therapy. CONCLUSIONS: Protease inhibitor-induced urinary stones are radiolucent and can cause high-grade ureteral obstruction. Protease inhibitor-induced urinary stones were not identified on unenhanced abdominal CT scans. The radiolucent gelatinous nature of such stones makes lithotripsy a poor choice of treatment. Ureteral stenting may allow spontaneous stone passage if symptomatic obstruction occurs. Urologists may encounter a greater number of patients with symptomatic protease inhibitor-induced urinary calculi as these medications become more popular.

Adult↗
PubMed1996

New technique in managing ureteropelvic junction obstruction: percutaneous endoscopic pyeloplasty.

Endopyelotomy is currently advocated for management of the obstructed ureteropelvic junction (UPJ). Healing of the stented UPJ occurs by secondary intention. Regardless of the method employed, success rates approach 85%. In order to increase the rate of success, we have devised a method of performing endopyelotomy in conjunction with endoscopic suturing of the incised UPJ. Two methods were developed to allow for the placement of a single absorbable monofilament suture. In the first method, endopyelotomy is carried out in the standard antegrade manner, and endoscopic suturing is performed with the use of a second retroperitoneal access sheath at the UPJ. In the second method, endoscopic placement of the suture is carried out through the standard renal access sheath, with suturing performed via the nephroscope. We have performed endoscopic pyeloplasty in eight patients. With a mean follow-up of 12 months, the procedure was successful in seven of these patients. Endoscopic suturing of the UPJ is technically demanding, but once sufficient expertise is gained, it may be utilized for immediate tissue coaptation, possibly decreasing urinary extravasation and, it is hoped, maximizing the caliber of the UPJ.

Adult↗