Biomedical subjects

D Duane Baldwin

Publications and source records attributed to D Duane Baldwin.

13 recordsLinked to original sources

PubMed2006

Multidetector computerized tomography angiography to predict lumbar venous anatomy before donor nephrectomy.

PURPOSE: Multidetector computerized tomography angiography has been used to predict renal anatomy before donor nephrectomy. Unrecognized lumbar veins represent a significant risk during laparoscopic surgery but to our knowledge no previous group has attempted to predict lumbar veins with multidetector computerized tomography angiography before laparoscopic donor nephrectomy. We evaluated the ability of multidetector computerized tomography angiography to preoperatively predict the size and location of anomalous left lumbar veins. MATERIALS AND METHODS: A prospective study was performed in patients undergoing left hand assisted laparoscopic donor nephrectomy from January 2003 to September 2004. All patients were imaged using 4-phase computerized tomography, including computerized tomography angiography with 1.25 mm collimation of the arterial and venous phases. Each multidetector computerized tomography angiogram was prospectively reviewed by a radiologist and operating surgeon, and retrospectively reviewed by a second blinded radiologist. RESULTS: A total of 70 patients underwent left hand assisted laparoscopic donor nephrectomy between January 2003 and September 2004. Five patients underwent imaging elsewhere and were excluded from study. Of the remaining 65 patients 54 (83%) had at least 1 anomalous lumbar vein of any size recognized at surgery. Additionally, 33 of these 65 patients (51%) had an anomalous lumbar vein that was 3 mm or greater. These 3 mm or greater vessels carry a significant risk of bleeding and they were used in further calculations. As read by a radiologist and surgeon, the sensitivity and specificity of multidetector computerized tomography angiography compared to surgical identification were 97% and 91%, respectively. Positive and negative predictive values, and accuracy were 91.4%, 97% and 94%, respectively. CONCLUSIONS: Multidetector computerized tomography angiography accurately predicts lumbar venous anatomy before donor nephrectomy with high sensitivity, specificity and accuracy.

Adult↗

PubMed2006

A novel single step percutaneous access sheath: the initial human experience.

PURPOSE: A novel 1-step percutaneous access sheath NS has been developed that allows the insertion of a dilating balloon and renal access sheath in a single step. We present the initial human experience with this sheath. MATERIALS AND METHODS: We performed a retrospective chart and database review of the initial 30 consecutive patients undergoing percutaneous nephrostolithotomy using the NS. Data collected included patient demographics, operative and recovery parameters, and complications. RESULTS: Mean patient age was 50.4 years (range 11 to 81), mean body mass index was 31.63 kg/m(2) (range 17.1 to 65) and mean preoperative stone area was 6.23 cm(2) (range 1 to 14.6). Six and 3 patients had full and partial staghorn calculi, respectively. Access was achieved via the upper pole in 16 patients, middle pole in 7 and lower pole in 7. Mean operative time was 114.8 minutes (range 61 to 237). Mean estimated blood loss was 145.5 cc (range 10 to 500) and mean postoperative hospital stay was 4.89 days (range 2 to 14). A total of 23 patients (76.7%) had no residual calculi on postoperative computerized tomography, 5 (16.7%) had residual fragments 4 mm or less and 2 (6.7%) had residual stone fragments greater than 4 mm. There were no complications related to the NS. CONCLUSIONS: The NS is safe, easy to use and has potential advantages compared to currently available renal access sheaths.

Adolescent↗

PubMed2006

Urothelial carcinoma after external beam radiation therapy for prostate cancer.

PURPOSE: We reviewed the clinical course of patients in whom urothelial carcinoma developed following radiation therapy for prostate cancer. MATERIALS AND METHODS: A retrospective review of all patients between 1990 and 2005 with the diagnosis of bladder and prostate cancer was performed. Of 125 total patients new onset urothelial carcinoma developed in 11 after undergoing external beam radiation therapy for prostate cancer. RESULTS: Whole pelvis external beam radiation therapy with a proton boost to the prostate was the radiation modality in 7 of the 11 patients (64%), while the remaining 4 patients received standard external beam radiation only. Urothelial carcinoma was detected a mean of 3.07 years after completion of radiation therapy in the proton group, compared to a mean latency period of 5.75 years in the standard radiation group (p = 0.09). Average patient age at diagnosis was 72 years (range 64 to 84). All patients presented with gross hematuria and had cystoscopic findings of coexisting radiation cystitis. Of the 11 patients 5 (45%) presented with grade 3 carcinoma and eventually 7 (64%) required radical cystectomy. Urothelial tumors with sarcomatoid features (carcinosarcoma and spindle cell sarcomatoid) developed in 2 patients (18%). Of the 11 patients 10 (91%) were nonsmokers at the time of urothelial carcinoma diagnosis. CONCLUSIONS: Urothelial carcinoma in patients with previous radiation therapy for prostate cancer is often high grade, and the majority of patients have cancer progression requiring cystectomy. A high incidence of urothelial carcinoma with sarcomatoid features was seen in these patients.

Aged↗

PubMed2005

Control of the renal artery and vein with the nonabsorbable polymer ligating clip in hand-assisted laparoscopic donor nephrectomy.

BACKGROUND: The large and variable size of the renal vein has prompted most surgeons to select linear stapling devices to secure the vein during laparoscopic donor nephrectomy. Although effective, these stapling devices have a potential for misfire. Use of the nonabsorbable polymer ligating (NPL) clip during laparoscopic donor nephrectomy provides increased graft vessel length compared with the stapling device, and the NPL clip has a locking mechanism which may increase security compared with standard titanium clips. The objective of this study was to evaluate the safety and efficacy of the NPL clip for control of the renal artery and vein during hand-assisted laparoscopic donor nephrectomy (HALDN). METHODS: A retrospective chart review of 50 consecutive HALDN patients was conducted where two parallel NPL clips were used to control both the renal artery and vein. Information collected included demographic data, operative and postoperative data, and complications. RESULTS: Mean donor age was 33.4 years and body mass index was 25.8 kg/m2. Mean operative time was 266.0 min, mean hospital stay was 3.2 days, and mean warm ischemia time was 123.3 seconds. There were no transfusions, open conversions, or complications related to use of the NPL clip. A US 16,300 dollars disposable cost savings was seen during this 1-year period alone. CONCLUSIONS: The NPL clip was 100% safe and effective in controlling the renal artery and vein during HALDN, allowed for additional vessel length, and resulted in a disposable cost savings of US 362 dollars per patient.

Adult↗

PubMed2005

Simplified technique for laparoscopic extravesical ureteral reimplantation in the porcine model.

BACKGROUND AND PURPOSE: Laparoscopic intravesical and standard Lich-Gregoir repair have been reported but are technically challenging. Herein, we present our experience with a simplified laparoscopic reimplantation of the ureter to correct vesicoureteral reflux (VUR). MATERIALS AND METHODS: Bilateral VUR was created cystoscopically in six minipigs, as confirmed by a static cystogram 6 weeks later. The laparoscopic extravesical correction of VUR was performed utilizing a full-thickness cystotomy. The ureter was transposed inside the bladder, and a full-thickness bladder closure was performed. No attempt was made to cover the ureter with urothelium. No stents or catheters were utilized postoperatively. Three months after reimplantation, the animals were evaluated with serology, a static cystogram, an intravenous urogram (IVU), and gross pathologic and histopathologic examination. RESULTS: The postoperative cystograms confirmed no reflux in all the reimplanted ureters and residual grade 1 to 3 reflux in the non-reimplanted ureters. All pigs voided normally and were completely continent. Cystoscopic evaluation revealed complete epithelialization over the reimplanted ureter. One surgical complication occurred: the ureter was incorporated into the bladder closure and became obstructed. The IVU in all other pigs demonstrated patent ureters with prompt function. CONCLUSIONS: Laparoscopic reimplantation of the ureter utilizing this modified Lich-Gregoir approach corrected reflux in all animals. The full-thickness bladder incision and intravesical transposition of the ureter greatly simplifies the laparoscopic procedure. This laboratory experience encourages further clinical evaluation in the pediatric population with VUR.

Animals↗

PubMed2005

Hand-assisted laparoscopic partial nephrectomy in the porcine model using gelatin matrix hemostatic sealant without hilar occlusion.

BACKGROUND AND PURPOSE: Gelatin matrix hemostatic sealant (GMHS) has been used for hemostasis during partial nephrectomy with hilar clamping. The objective of this study was to determine the ability of GMHS to achieve hemostasis without hilar clamping in the porcine model. MATERIALS AND METHODS: In this feasibility study, eight farm pigs underwent a left-hand-assisted laparoscopic partial nephrectomy (HALPN). The lower fourth of the kidney was removed with cold scissors, and GMHS was applied laparoscopically. Samples were collected for measurement of serum hemoglobin (Hb) and creatinine (Cr) prior to surgery and at 4 and 30 days after HALPN. The kidneys were harvested at 30 days, and retrograde pyelograms and pathologic analysis were performed. RESULTS: Application of GMHS achieved complete hemostasis in all eight animals. The mean estimated blood loss was 40 mL, and the operating time was short (mean 92.5 minutes). In three kidneys, a significant collecting system opening was noted but not repaired. At harvest, there were no hematomas, infections, or urine leaks in any animals. In one animal, a 2-cm contained fluid collection was identified. There was no difference in the preoperative and harvest Hb (9.63 v 9.21 g/dL; P = 0.49), but there was a slight increase in Cr (1.21 v 1.46 mg/dL; P = 0.01) possibly because of the decreased renal mass after partial nephrectomy. CONCLUSION: Even without hilar occlusion, GMHS was 100% safe and effective in controlling bleeding after HALPN in the porcine model. Avoidance of hilar occlusion may reduce the risk associated with warm renal ischemia and the extra dissection required to isolate the hilum in preparation for clamping.

Animals↗

PubMed2005

Comparison of nonabsorbable polymer ligating and standard titanium clips with and without a vascular cuff.

PURPOSE: To compare the efficacy of nonabsorbable polymer ligating (NPL) and titanium clips applied with and without a 1-mm vascular cuff at physiologic and supraphysiologic pressures. MATERIALS AND METHODS: An in vitro equine-vessel model was created to test clip occlusion strength. Ten-millimeter NPL and standard Ti clips were applied to veins (10 mm) and arteries (10, 6, and 5 mm) with and without a 1-mm cuff and tested until they held a pressure of 300 mm Hg (veins) or 760 mm Hg (arteries) for 2 minutes or leaked. RESULTS: The NPL clip was statistically more secure on 10-mm veins with and without a cuff, 10-mm arteries with and without a cuff, and 6-mm arteries with a cuff than was the Ti clip. Leaving a 1-mm cuff resulted in a statistically higher leak point in all vessels tested except the 6-mm arteries secured with the Ti clip. CONCLUSIONS: The NPL clip was more secure than the Ti clip on larger arteries and veins. A 1-mm vascular cuff enhances the security of both NPL and Ti clips in vessels of all sizes. The NPL clip is secure and reliable in securing both arteries and veins.

Animals↗

PubMed2005

A clinical pathway for laparoscopic pyeloplasty decreases length of stay.

PURPOSE: Benefits of minimally invasive procedures include decreased hospitalization and recovery times. Decreased length of stay (LOS) improves hospital efficiency and decreases costs. However, decreasing the LOS at the expense of patient care and satisfaction is not acceptable. A clinical pathway (CP) with structured order sets and imaging was developed for patients undergoing laparoscopic pyeloplasty. This pathway includes a cascade of activities managed closely by the health care team. This study assesses the safety and patient satisfaction with this clinical pathway. MATERIALS AND METHODS: We reviewed all adult pyeloplasties (39) completed laparoscopically since November 2001. All patients were managed according to the CP developed for the laparoscopic pyeloplasty procedure. The length of stay was measured in days. Patient satisfaction was assessed with a standardized questionnaire. Any readmissions or emergency room visits were documented. RESULTS: The mean length of stay was 1.10 days. Of 39 patients 37 (94%) were discharged home on postoperative day 1. One patient with severe postoperative pain required intravenous analgesia. She had undergone complex upper tract reconstruction and stayed a total of 4 days. One patient, who had a previous failed endopyelotomy, remained 2 days for persistent nausea. No patients sought emergency room consultation and there were no readmissions. Of 39 patients 34 (87%) completed the questionnaire and satisfaction was high. CONCLUSIONS: The implementation of a CP at our institution has standardized patient care in this population and decreased LOS in comparison to the literature. This improves bed use and hospital efficiency while maintaining a high degree of patient satisfaction. We conclude that with intensive patient care and education most patients undergoing laparoscopic pyeloplasty may be discharged home safely on postoperative day 1.

Academic Medical Centers↗

PubMed2004

Laparoscopic warm renal ischemia in the solitary porcine kidney model.

OBJECTIVES: To determine the effect of a laparoscopic approach on warm renal ischemia in the pig with a solitary kidney. Although the maximal safe duration for warm ischemia during open partial nephrectomy is commonly accepted to be 30 minutes, the maximal safe ischemic time during laparoscopic partial nephrectomy has not been previously determined. METHODS: Sixteen farm pigs underwent unilateral laparoscopic right nephrectomy. Two weeks later, the pigs underwent complete laparoscopic mobilization of the remaining left kidney and were randomized to complete hilar clamp times of 0, 30, 60, or 90 minutes. Serum creatinine was evaluated before right nephrectomy and at days 0, 2, 4, 7, 14, and 30 after renal ischemia during laparoscopy. All renal specimens were evaluated by an experienced nephropathologist in a blinded fashion. RESULTS: The serum creatinine remained stable at all points in the control and 30-minute ischemia groups. The serum creatinine level rose initially on days 2 and 4 in the 60-minute and 90-minute ischemia groups but returned to baseline by day 7. At harvest, no statistically significant difference was found among the groups in serum creatinine or histologic features. CONCLUSIONS: Renal ischemic times up to 90 minutes during laparoscopy were well tolerated by the solitary porcine kidney. Possible explanations for this finding include the protective effect of a solitary kidney and the potential protective effect of relative ischemic preconditioning provided by the pneumoperitoneum.

Animals↗

PubMed2004

Hand-assisted laparoscopic donor nephrectomy is safe and results in increased kidney donation.

The impact of hand-assisted laparoscopic donor nephrectomy on kidney allograft function, perioperative complications, and organ supply was evaluated by retrospective analysis of 41 hand-assisted laparoscopic donor nephrectomy patients and their recipients between January and October 2003. Serum creatinine at discharge, length of stay, estimated blood loss, operative time, and perioperative complications were analyzed. The mean values for laparoscopic donors and their recipients were 1.2 +/- 0.3 and 1.3 +/- 0.8 mg/dL for creatinine, 3.3 +/- 0.8 and 6.7 +/- 3 days for length of stay, and 110.4 +/- 76.9 and 111.6 +/- 56 mL for estimated blood loss, respectively. No major complications occurred in the laparoscopic donors. The number of living kidney donors increased by 94% compared to the mean of the previous 4 years following implementation of the laparoscopic program. Hand-assisted laparoscopic donor nephrectomy is safe, results in excellent allograft function, and significantly increases donation.

Adolescent↗

PubMed2003

Single-center comparison of laparoscopic pyeloplasty, Acucise endopyelotomy, and open pyeloplasty.

PURPOSE: To compare Acucise endopyelotomy (Applied Medical, Irvine, California), laparoscopic pyeloplasty, and open pyeloplasty in the treatment of ureteropelvic junction (UPJ) obstruction. PATIENTS AND METHODS: A retrospective review of all adult patients undergoing surgical correction of UPJ obstruction between December 1999 and August 2001 at Vanderbilt University Medical Center was performed. Patients undergoing UPJ correction with Acucise endopyelotomy (N = 9), laparoscopic pyeloplasty (N = 16), and open pyeloplasty (N = 7) were compared in regard to demographic information, operative data, recovery parameters, cost data, and outcome (as determined by diuretic renography, the Whitaker test, or both). RESULTS: Success rates of 56%, 94%, and 86% were obtained for Acucise endopyelotomy, laparoscopic pyeloplasty, and open pyeloplasty, respectively. There were no differences between the Acucise endopyelotomy and laparoscopic pyeloplasty groups in age, American Society of Anesthesiology (ASA) score, length of follow-up, estimated blood loss (EBL), hospital stay, total hospital cost, or analgesic requirement. The Acucise patients demonstrated shorter operating times (1.7 v 3.3 hours; P < 0.001) and time to oral intake (7.9 v 16 hours; P = 0.008) than the laparoscopic pyeloplasty group. When the laparoscopic pyeloplasty patients were compared with the open pyeloplasty patients, there was no difference in operative time, EBL, time to oral intake, or total hospital costs. The laparoscopically treated patients demonstrated significantly lower analgesic requirements (27.2 v 124.2 mg of morphine sulfate equivalent; P = 0.02) and shorter hospital stays (1.4 v 3.0 days; P = 0.03) than the open surgery patients. The Acucise patients demonstrated shorter operative time (1.7 v 3.4 hours; P < 0.001), shorter hospital stay (1.3 v 3.0 days; P = 0.02), and lower analgesic requirement (22.4 v 124.2 mg of morphine sulfate equivalent; P = 0.02) than the open surgery patients. CONCLUSIONS: Laparoscopic pyeloplasty achieves a success rate equal to that of open pyeloplasty while providing a recovery similar to that obtained with Acucise endopyelotomy and is gaining popularity as the treatment of choice for UPJ obstruction.

Adolescent↗

PubMed2003

Single-center comparison of purely laparoscopic, hand-assisted laparoscopic, and open radical nephrectomy in patients at high anesthetic risk.

BACKGROUND AND PURPOSE: The laparoscopic approach for management of high-risk patients with renal-cell carcinoma (RCC) may reduce perioperative and postoperative morbidity. The aim of this study was to compare the outcome of purely laparoscopic radical nephrectomy (LRN), hand-assisted laparoscopic radical nephrectomy (HALRN), and open radical nephrectomy (ORN) for renal tumors in a population of patients at high risk for perioperative complications. PATIENTS AND METHODS: All patients undergoing radical nephrectomy for presumed RCC between August 1999 and August 2001 at Vanderbilt University Medical Center and having an American Society of Anesthesiologists (ASA) score of >/=3 were reviewed. Patients with known metastasis, local invasion, caval thrombi, or additional simultaneous surgical procedures were excluded from analysis. Thirteen patients underwent LRN, eight patients underwent HALRN, and 26 underwent ORN. The patient demographics were similar in the three groups. The groups were compared with regard to intraoperative and postoperative parameters. Statistical analysis was done using chi-square testing for categorical variables and analysis of variance (ANOVA) for continuous variables. Differences in outcomes were examined using ANOVA and Dunnett's T for pairwise comparisons. RESULTS: The ASA 4 patients had significantly longer hospital stays and total hospital costs than the ASA 3 patients. The mean operative time in the ASA 3 patients was similar in the three groups: 2.8 hours, 2.8 hours, and 2.5 hours for the LRN, HALRN, and ORN patients, respectively. Both the LRN patients (22.9 mg of morphine sulfate equivalent) and the HALRN patients (42.1 mg) required less pain medication than the open surgery patients (97.7 mg). When the total hospital costs were compared, LRN was less costly than HALRN ($6089 v $7678; P = 0.57) and open surgery ($6089 v $7694; P = 0.04). The complication rate in the LRN, HALRN, and ORN group was 0%, 25%, and 27%, respectively, although the differences were not statistically different (P = 0.12). CONCLUSIONS: Both LRN and HALRN can be performed safely in patients with significant comorbid conditions. Careful preoperative preparation, intraoperative monitoring, and awareness of laparoscopy-induced oliguria can preclude inadvertent overhydration, hemodilution, and congestive heart failure. Both LRN and HALRN result in less pain medication requirement and faster return to oral intake than ORN, and LRN results in fewer perioperative complications than HALRN or ORN in patients at high perioperative risk. The LRN technique has a 21% lower total cost than both HALRN and ORN.

Adult↗

PubMed2003

Simplified laparoscopic radical cystectomy with orthotopic ileal neobladder creation in a porcine model.

BACKGROUND AND PURPOSE: Laparoscopic radical cystectomy with orthotopic ileal neobladder creation is a technically challenging and lengthy surgical procedure. We present our experience with a simplified technique for laparoscopic cystectomy and neobladder creation in the porcine model. MATERIALS AND METHODS: Ten female minipigs underwent a purely laparoscopic radical cystectomy with orthotopic ileal neobladder creation. Nine ureterointestinal anastomoses were performed using a simplified "dunk" technique, where the ureter was prolapsed 5 mm into the afferent limb and the periureteral tissue was secured to the bowel serosa with three superficial sutures. Six ureters were not stented, and three had indwelling stents inserted. In 11 ureters, the anastomosis was performed using a running mucosa-to-mucosa technique (three with stents, eight without stents). The Lapra-Ty suture clip (Ethicon Endosurgery, Cincinnati, OH) was used to secure the running sutures on the urethra, ureters, and neobladder. Animals were harvested at 3 to 8 weeks (mean 6.5 weeks) after surgery. Serology, static cystogram, intravenous urography, and gross and histopathologic evaluations were performed. RESULTS: Of six unstented dunked ureterointestinal anastomoses, two (33%) were widely patent, two were strictured but patent, and two were completely obstructed. In the three stented ureters implanted using the dunk technique, one (33%) was widely patent, one was strictured, and one was completely obstructed. All ureterointestinal anastomoses performed with a mucosa-to-mucosa running anastomosis, whether stented (three ureters) or not stented (eight ureters), were widely patent. Lapra-Ty clip migration into the neobladder pouch caused urethral obstruction resulting in delayed bladder perforation in two animals. CONCLUSIONS: Laparoscopic cystectomy and ileal neobladder creation is technically feasible. Attempts to simplify the ureterointestinal anastomosis require further evaluation and modification. Stent placement appears to be unnecessary in the laparoscopic ureterointestinal anastomosis. Laparoscopic creation of the ileal neobladder remains a technically challenging procedure.

Anastomosis, Surgical↗