Biomedical subjects

Patrick Antiphon

Publications and source records attributed to Patrick Antiphon.

7 recordsLinked to original sources

PubMed2003

Preparedness in robotically assisted interventions.

For many years, robots have been used in manufacturing to perform a variety of delicate tasks. Their use is now being generalized to other fields, such as biology, domestic applications, and especially medicine, in which they are poised to make a significant contribution. This evolution comes from the progress made in the field of robotics and from recent changes in medical and surgical techniques, namely, developments in medical imaging and a new desire for minimally invasive interventions. This emerging combination of high-precision robotic manipulators, new medical diagnostic techniques, and efficient minimally invasive surgery has not yet been perfected. After a brief discussion of state-of-the-art robotic systems used in urology, this article discusses new challenges presented by robotic minimally invasive surgery. A computer-integrated approach aimed at increasing the efficiency of such interventions through better preparedness is presented. This approach is illustrated by a case study in human nephrectomy and a cardiac animal experiment.

Humans↗

PubMed2003

Laparoscopic and robotic surgical training in urology.

The most important change in urology during the past decade was the development of minimally invasive surgery, particularly laparoscopy. However, the main drawback of laparoscopy is a steep learning curve, which results from the significant changes in the surgical environment. Although laparoscopy can provide important advantages for the patient, including decreased length of hospitalization, decreased analgesic requirement, and a shortened postoperative convalescence, one concern has been whether laparoscopic techniques should be learned solely in the operating room. For example, sports, music, and aviation are practiced before an actual performance is ever undertaken. In this review, the advantages and limitations of all available training modalities in minimally invasive surgery are described. Testing basic laparoscopic skills on inanimate models, becoming familiar with the principles of dissection and hemostasis on living animals, and studying surgical anatomy on cadavers should be considered as indispensable and complementary elements for laparoscopic training in the future. In addition, telementoring with the help of modern image processing and virtual reality eventually may become the basis of tomorrow's surgical instruction.

Clinical Competence↗

PubMed2003

Assessment of surgical technique and perioperative morbidity associated with extraperitoneal versus transperitoneal laparoscopic radical prostatectomy.

OBJECTIVES: To compare the perioperative morbidity and surgical technique of the two main variants of laparoscopic radical prostatectomy: the more often used transperitoneal approach with primary dissection of the plane posterior to the seminal vesicles (TP-LRP) and a purely extraperitoneal approach (EP-LRP). METHODS: Our initial 20 consecutive patients who underwent EP-LRP and the last 20 consecutive patients who underwent TP-LRP were included in this retrospective study. The two groups were well matched for age, American Society of Anesthesiologists score, body mass index, prostate-specific antigen level, and Gleason score. The mean time for completion of the individual laparoscopic steps was assessed for both approaches. RESULTS: With EP-LRP, the mean operative time was shorter (169.6 minutes versus 224.2 minutes, P <0.001) and patients resumed a full diet earlier (mean 1.6 days versus 2.6 days, P = 0.002). The mean total dose and duration of morphine administration were higher in the TP-LRP group, but the difference was not statistically significant (6.0 mg versus 12.8 mg and 0.5 day versus 0.9 day, respectively). The catheter time was nearly identical in the two groups (mean 5.3 days with TP-LRP and 4.2 days with EP-LRP). The incidence of positive margins was not affected by the surgical approach. CONCLUSIONS: These preliminary results suggest that the initial posterior dissection associated with TP-LRP is less efficacious than direct access of the prevesical space during EP-LRP. Measures of perioperative morbidity were at least equivalent, if not superior, for the EP-LRP technique. These findings, together with the significant decrease in operative time with EP-LRP, appear sufficiently important to abandon the transperitoneal technique.

Aged↗

PubMed2003

Prospective evaluation of a 21-sample needle biopsy procedure designed to improve the prostate cancer detection rate.

OBJECTIVES: To evaluate prospectively the diagnostic yield of a 21-sample ultrasound-guided needle biopsy procedure for prostate cancer in patients with elevated serum prostate-specific antigen and/or abnormal digital rectal examination findings. METHODS: Between December 2000 and May 2002, 303 patients underwent 21-sample needle biopsy under local anesthesia, comprising sextant biopsies at a 45 degrees angle, 3 biopsies in each peripheral zone at an 80 degrees angle, 3 biopsies in each transition zone (TZ), and 3 biopsies in the midline peripheral zone. Morbidity was assessed clinically. A short questionnaire was filled out by 90 consecutive patients. RESULTS: The cancer detection rate using 6 biopsy samples (sextant biopsies only), 12 samples (sextant plus lateral biopsies), 18 samples (sextant plus lateral plus TZ biopsies), and 21 samples (sextant plus lateral plus TZ, plus midline biopsies) was 22.7%, 28.3%, 30.7%, and 31.3%, respectively. The 21-sample procedure statistically improved the cancer detection rate by 37.9% relative to the 6-sample procedure. The improvement was most marked in patients with a prostate volume of more than 40 cm(3) (48.3%), patients with Stage T1c prostate disease (44.9%), patients undergoing repeat biopsy (66.2%), and patients with prostate-specific antigen levels greater than 10 ng/mL (38.5%). Adverse effects were infrequent (3%), consisting of prostatitis in 3 patients, acute urinary retention in 6 patients, and rectal bleeding requiring hospitalization in 1 patient taking aspirin. Using the questionnaire, 84% of patients reported macroscopic hematuria for an average of 3.4 days and hematospermia for 12.8 days, and 45% reported minor rectal bleeding lasting 1.1 days. The mean pain score, with a visual analog scale ranging between 0 (no pain) and 10 (intense pain), was 4.56. CONCLUSIONS: A 21-sample needle biopsy procedure increased the prostate cancer detection rate relative to a 6-sample procedure, without increasing morbidity. Patients with elevated prostate-specific antigen values should undergo sextant biopsies and at least 6 additional biopsies in the peripheral zone and 6 in the TZ.

Aged↗

PubMed2003

Positive surgical margins in laparoscopic radical prostatectomy: the impact of apical dissection, bladder neck remodeling and nerve preservation.

PURPOSE: We assess the incidence and location of positive surgical margins in a consecutive series of patients who underwent laparoscopic radical prostatectomy. MATERIALS AND METHODS: Between May 1998 and September 2001, 235 men underwent laparoscopic radical prostatectomy at our institution. During this period modifications were made in the technique. We stopped preserving the puboprostatic ligaments during 1999 and stopped preserving the bladder neck during 2000. We compared the incidence of apical and bladder neck margins before and after these changes in surgical technique. Nerve sparing status was documented by the surgeon at the end of the operation and its effect on the incidence of lateral positive margins was evaluated. To concentrate on the surgically induced margins this study focused on pT2 cases. RESULTS: There were 169 pT2 cases and 32 (18.9%) positive margin locations. A constant decrease was noted in the overall incidence of positive margins but, while apical margins were the most abundant in 1998, posterolateral margins were most abundant in 2001. Avoiding bladder neck preservation eliminated positive bladder neck margins in 2001. The overall incidence of positive lateral surgical margins in pT2 cases treated with a nerve sparing procedure was 8.4%. CONCLUSIONS: The experience gained in this procedure led to a decrease in the incidence of positive margins. Wide resection of the bladder neck and cutting the puboprostatic ligaments decreased bladder neck and apical positive margins. Nerve preservation did not increase the incidence of positive margins. These technical modifications may improve the outcome of laparoscopic radical prostatectomy.

Aged↗

PubMed2003

Laparoscopic radical prostatectomy: description of the extraperitoneal approach using the da Vinci robotic system.

PURPOSE: We developed and assessed the feasibility of extraperitoneal laparoscopic radical prostatectomy performed using the da Vinci (Intuitive Surgical, Mountain View, California) robotic system. MATERIALS AND METHODS: In June 2002, 4 consecutive patients with clinically localized prostate cancer underwent extraperitoneal, robotic assisted laparoscopic radical prostatectomy. After development of the extraperitoneal space the surgeon performed laparoscopic prostatectomy from the remote control unit. The assistant aligned and exchanged robotic instruments and used conventional laparoscopic instruments to facilitate prostatectomy. Perioperative data and pathological results were recorded. RESULTS: No difficulties were noted when developing the extraperitoneal space. All additional steps were successfully performed with telerobotics. More distal placement of the robotic ports appeared to improve the feasibility of the extraperitoneal approach. The peritoneum acted as a natural bowel retractor and the distal port placement facilitated use of the assistant ports. Mean operative time was 274 minutes (range 124 to 360). Mean catheterization time and hospital stay were 2.7 and 5.3 days, respectively. A positive margin was observed in 1 patient and pathological stage was pT2 in 3 and pT3 in 1. No postoperative complications or open conversions were observed. CONCLUSIONS: The extraperitoneal approach was feasible with the da Vinci robotic system. Distal port placement for the robot appeared to create an ergonomic environment for the surgeon and assistant and more direct prostatic access. While additional clinical experience is required, the extraperitoneal approach may ultimately provide advantages for robotic and nonrobotic laparoscopic radical prostatectomy.

Aged↗

PubMed2003

Prognostic consequences of the location of positive surgical margins in organ-confined prostate cancer.

INTRODUCTION: The purpose of the present study was to evaluate and compare the risk of progression in organ-confined prostate cancers (stage pT2), according to the location of positive surgical margins. MATERIALS AND METHODS: Between 1988 and 2001, 538 consecutive men underwent radical prostatectomy for localized prostate cancer. All patients had preoperative physical examinations, serum PSA assays (Hybritech assay, N.l. <4 ng/ml) and ultrasound-guided sextant biopsies to confirm diagnosis. Radical prostatectomy specimens were analyzed according to the Stanford protocol. Positive margins were classified as single or multiple and main locations (apex, bladder neck and posterolateral) were noted. Postoperative follow-up data were obtained through routine serum PSA assays. Biochemical recurrence was defined as a single postoperative PSA level >0.2 ng/ml. Biochemical progression was studied in patients with organ-confined tumors (stage pT2) according to the location of the single positive margin. Kaplan-Meier analysis was performed to determine the actuarial biochemical recurrence-free likelihood and the log-rank test was used for statistical analysis. Differences were considered significant when the p value was <0.05. RESULTS: 371 patients had organ-confined tumors, and 60 patients (16.1%) had solitary positive margins (apex 26, bladder neck 14, posterolaterally 20). Eleven patients (18.3%) had biochemical progression. 5-year biochemical free progression was 54.5, 76.9 and 87.9% for apex, bladder and the posterolateral location, respectively (p < 0.05). CONCLUSIONS: In the present study, a positive surgical margin at the apex was associated with worse clinical prognosis compared to the bladder neck and posterolateral locations.

Humans↗