Biomedical subjects

Andrew A Wagner

Publications and source records attributed to Andrew A Wagner.

8 recordsLinked to original sources

PubMed2006

Transmesenteric laparoscopic pyeloplasty.

PURPOSE: Traditionally transperitoneal laparoscopic access to ureteropelvic junction obstruction has been performed in retrocolic fashion. We assessed transmesenteric laparoscopic pyeloplasty to correct ureteropelvic junction obstruction and compared results to those in patients undergoing traditional retrocolic laparoscopic pyeloplasty. MATERIALS AND METHODS: Between August 1999 and July 2005, 188 consecutive transperitoneal laparoscopic pyeloplasties were performed at our institution. A total of 18 patients underwent a transmesenteric approach and 170 underwent the classic retrocolic approach. Patient selection for the transmesenteric approach was at surgeon discretion with the inclusion criterion of recognition of the renal pelvis and/or ureter through the descending colonic mesentery. RESULTS: Compared to patients undergoing traditional retrocolic procedure the transmesenteric approach was more commonly applied in younger individuals and males, and for pathological conditions on the left side and malrotated kidneys. The transmesenteric approach lowered operative time by a mean of 22.5% and decreased hospital stay by 19.2%. The patency success rate was 100% at a mean followup of 18.6 months for the transmesenteric approach and 94.1% at a mean followup of 22 months for the retrocolic approach. CONCLUSIONS: In a select group of patients transmesenteric pyeloplasty may represent a more rapid alternative to the transperitoneal retrocolic approach and speed convalescence with similar success rates.

Adolescent↗

PubMed2006

Comparison of surgical performance during laparoscopic radical prostatectomy of two robotic camera holders, EndoAssist and AESOP: a pilot study.

OBJECTIVES: Robotic camera holders provide steady camera movement and view during laparoscopic surgery. We compared two such robots, EndoAssist and AESOP, by evaluating timed setup and surgical performance during laparoscopic radical prostatectomy (LRP). METHODS: We prospectively collected data for 20 patients undergoing LRP using either the EndoAssist or AESOP. AESOP was mounted to the surgical bed and controlled by an experienced assistant using a hand-held remote control. The EndoAssist device was placed over the patient's right shoulder. Its movements were executed by the surgeon using a head-mounted optical emitter with brief head movements detected by a sensor mounted atop the surgeon's video monitor. The robot setup time and LRP operative steps were timed and compared between the two cohorts. RESULTS: The time for robot setup favored AESOP over the EndoAssist (2.0 minutes versus 5.3 minutes, P = 0.001). The time for accomplishing vas deferens and seminal vesicle dissection favored the EndoAssist (23 minutes versus 33 minutes, P = 0.04). However, no statistically significant difference was found in the efficiency of task performance between the two robots in any of the other 11 steps measured. CONCLUSIONS: The EndoAssist appears to be equally efficient to the assistant-controlled AESOP robot with respect to surgical performance during LRP. The advantages of the EndoAssist include its accurate response and ability to provide the surgeon with complete control of the desired operative view without relying on an assistant. Its disadvantages include its large profile, lack of a table-mounted design, and the need for pedal activation. Additional modifications are needed to improve the efficiency and design of this novel robotic device further.

Humans↗

PubMed2006

Anatomic nerve-sparing laparoscopic radical prostatectomy: comparison of retrograde and antegrade techniques.

OBJECTIVES: To compare the anatomic retrograde and antegrade preservation of the neurovascular bundle (NVB) during laparoscopic radical prostatectomy. METHODS: Anatomic studies were reviewed, focusing on the fascial layers surrounding the prostate and NVB and the terminology used as described by Walsh and colleagues. Important operative steps have been illustrated using video clips. For the retrograde technique, after incision of levator fascia, the NVBs were released from the apex before division of the urethra. Along the plane between the laterally incised Denonvilliers and perirectal fascia, the prostate was mobilized from the rectum. Isolated clipping of the seminal vesicle arteries was performed in an antegrade manner, followed by control of the lateral pedicles, and identification of the course of the NVB. For the antegrade technique, after dissection of the seminal vesicles, the levator fascia was incised to develop a lateral NVB groove. After bladder neck division and lateral pedicle ligation, the lateral NVB groove was used as a guide for antegrade preservation of the NVB. During anastomosis, the NVBs located at the 5-o'clock and 7-o'clock positions were avoided in both techniques. RESULTS: A questionnaire-based potency rate of 67% and 76%, respectively, was reported after bilateral nerve sparing using retrograde and antegrade laparoscopic radical prostatectomy techniques. CONCLUSIONS: Both techniques allowed replication of open surgical principles. The video magnification enabled excellent demonstration of the periprostatic anatomy. The principles of interfascial dissection of the NVB, use of task-specific instrumentation, and avoiding energy sources around the NVB may be more important than the actual nerve-preservation technique used.

Humans↗

PubMed2006

Bladder irrigation using hydrogen peroxide for clot evacuation.

Evacuation of clot from the bladder by irrigation can be difficult when significant clot burden or organized clot exists. We describe a novel technique for the evacuation of clot from the bladder using irrigation containing hydrogen peroxide that facilitated clot removal.

Administration, Intravesical↗

PubMed2005

Imaging following cryoablation of a renal lesion.

BACKGROUND: An 81-year-old man presented with a history of right nephrectomy for renal cell carcinoma, chronic renal insufficiency and implanted defibrillator. He was asymptomatic. Contrast-enhanced CT and MRI were contraindicated. INVESTIGATIONS: Non-contrast CT, positron emission tomography (PET), fused PET-CT and Doppler ultrasound. DIAGNOSIS: Small exophytic left midpole renal tumor, 3.7 cm in size. MANAGEMENT: Percutaneous CT-guided renal cryoablation, followed up with PET-CT imaging.

Aged↗

PubMed2004

Acute renal failure resulting from huge inguinal bladder hernia.

We report a case of a huge inguinal/scrotal bladder hernia presenting as acute renal failure. A 66-year-old man with a large scrotal mass presented with metabolic acidosis and azotemia and was admitted to the intensive care unit. Computed tomography displayed the bladder completely herniated into the scrotum and bilateral hydronephrosis. After stabilization and percutaneous nephrostomy placement, the patient's creatinine markedly improved, and the hernia was repaired. Bilateral ureteral obstruction from a bladder hernia is a very rare event. Computed tomography is rapid and helpful in this situation. Hernia repair can safely be performed after nephrostomy drainage.

Acute Kidney Injury↗

PubMed2004

A novel, inexpensive, double lumen suprapubic catheter for urodynamics.

PURPOSE: We describe a novel, double lumen, intravesical, suprapubic catheter designed to meet the requirements of pediatric urodynamics that is easy to use and has minimal complications. MATERIALS AND METHODS: A commercially available 10Fr pediatric suprapubic pigtail catheter forms the outer lumen for instilling filling media. A 16 gauge epidural catheter is inserted through the outer catheter providing an inner lumen for measuring intravesical pressures. The resultant double-lumen catheter is inserted suprapubically using a peel away needle supplied with the 10Fr catheter, with the patient under general anesthetic. RESULTS: The catheter has been used for 15 years in more than 700 patients with good reliability and few complications. The concentric construction of the double lumens and the rigidity of the inner intravesical pressure channel ensure there is no transmission of pressure from the filling channel to the inner lumen. The catheter has a circular cross section and a pigtail distal end which help to retain it within the bladder. There is low resistance to filling that allows adequate filling rates to be achieved by gravity rather than necessitating a pump. The catheter is easily made from readily available components and is less expensive than other double-lumen catheters suitable for suprapubic use. CONCLUSIONS: A reliable, double lumen catheter that fulfills criteria not found in commercially available alternatives can be inexpensively made for urodynamics.

Catheterization↗

PubMedDate not supplied

Treatment of renal tumors with radiofrequency ablation.

BACKGROUND: Radiofrequency (RF) energy has been investigated as a minimally invasive modality for ablating small renal tumors. Recent advances in the application of this technology have improved its safety and effectiveness. MATERIALS AND METHODS: We describe the technology of RF application and review the current delivery systems as applied to renal tumor ablation. We also review relevant animal studies, which have revealed the natural history of ablated renal tissue. Finally, we examine recent human trials with an emphasis on longer-term follow-up, imaging, complications, and successful ablation according to tumor location within the kidney; i.e., central v peripheral. RESULTS: Radiofrequency ablation can be performed safely in a minimally invasive fashion either percutaneously or laparoscopically. Energy delivery varies, and available systems include dry, wet, cooled-tip, and bipolar electrodes. Heat rise and subsequent charring in the tissue adjacent to the electrode is limited by temperature or impedance-based feedback systems. In animal studies, ablation results in complete cell kill, as judged by nicotinamide adenine dinucleotide diaphorase staining. Clinical trials with intermediate follow-up show excellent success rates. Tumors >3 cm and central tumors have a higher recurrence rate after RFA than smaller, more peripheral tumors. CONCLUSIONS: The current literature suggests that RFA is a promising minimally invasive method of treating small renal tumors. Nevertheless, long-term follow-up is still required, and questions remain regarding the optimal delivery system, duration of ablation, and method of surveillance.

Animals↗