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Results for “Learning Curve”

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PubMed2002

[Immediate and long-term results of radiofrequency ablation of accessory atrioventricular pathways].

The aim of this study was to report the authors' experience of radiofrequency ablation of accessory atrioventricular pathways over a 10 year period (01-91 to 10-00), and the effect of the "learning curve" on the results. The data of 400 patients admitted to primo-ablation of a bundle of Kent was analysed retrospectively. A total of 481 ablations were performed (1.20 per patient). The cumulative global success in the 414 accessory pathways treated was 90.6%. The primary success rate increased from the 1st to the 4th quartile from 68 to 97% (p = 0.0001). The mean duration of fluoroscopy and number of ablation sites decreased from the 1st to the 4th quartile respectively from 47 +/- 27 to 25 +/- 18 minutes (p = 0.0001) and from 8.5 +/- 7.8 to 4.5 +/- 3.8 minutes (p = 0.0001). The average recurrence rate over the four quartiles was 3.6. The overall complication rate was 1.44%. The improved primary success rate from 1991 to 2000 and, in parallel, the reduction of the number of inappropriate ablation sites and fluoroscopy duration are explained not only by the "learning curve" of our centre but also by the benefits of the application of scientific acquisitions (unipolar recordings, criteria for ablation site localisation...) and technical progress (ablation with temperature monitoring...) over this period.

Adult↗

PubMed2005

Endovascular treatment for aortic disease: is a surgical environment necessary?

OBJECTIVE: Interventional radiologists, cardiologists, and vascular surgeons are capable of performing endovascular procedures successfully in their respective environments. Suboptimal anatomy or intraoperative technical problems can be encountered, and endovascular management alone is not always suitable. The objectives of this study were to define the incidence of adjunctive surgical techniques, to discuss the rationale for endovascular reconstruction in a well-developed surgical environment, and to assess the effect of experience on the incidence of adjunctive repair. METHODS: All primary aortic and aortoiliac elective, urgent, and emergent endovascular procedures performed at the Peter Lougheed Center and entered into a prospective database from May 25, 1999 to June 01, 2005, were reviewed. All adjunctive surgical techniques to enable stent deployment, enhance attachment site, or solve intraoperative difficulties were captured. The study period was divided into two time periods based on learning curve data to assess the effect of experience on the rate of adjunctive repairs. RESULTS: Four hundred thirty-eight patients underwent elective (80%), urgent (15%), or emergent (5%) endovascular procedures during the study period. These consisted of 101 thoracic and 337 abdominal operations, including the use of 13 fenestrated stents. One hundred thirty-nine patients (31.7%) required 180 open surgical procedures. Complete data were available for the entire patient cohort. The mean follow-up was 793.2 days (SD, 519.1 days). Procedures were necessary for vascular access, arterial dissection/rupture, limb ischemia, and enhancement/elongation of the stent attachment site. The persistent endoleak rate was 5.3%, the late rupture rate was 0.7%, the conversion rate was 1.6%, the 30-day surgical mortality rate was 3.2%, all-cause mortality to date is 7.3%, and the reintervention rate was 4.6%. There was no statistically significant effect of the learning curve on the incidence of surgical adjunctive procedures in either the thoracic group (11/26 [42.3%] for phase 1 vs 17/75 [22.6%] for phase 2) or the abdominal group (14/50 [28.0%] for phase 1 vs 97/287 [33.8%] for phase 2). Overall, 31.5% of patients required adjunctive surgical repair. CONCLUSIONS: Successful endografting requires endovascular expertise in addition to a well-developed surgical environment to increase applicability and decrease patient risk. Despite advances in endovascular technology, hybrid techniques will continue to be required to achieve good overall success rates.

Aged↗

PubMed2005

[The treatment of inguinofemoral hernias with laparoscopic herniorraphy. Our experience of 1210 transabdominal preperitoneal (TAPP) reconstructions].

In 11 years (1994-2005) our team has carried out 1210 transabdominal preperitoneal herniorrhaphies in 964 patients. We operated monolateral hernias in 602 (62.4%) patients, bilateral hernias in 246 (25.5%), among these occult contralateral hernias in 96 (10%), femoral hernias 20 (2%). 28% (N=269) of all operations were performed on because of recurrent hernias. In 6 selected patients incarcerated hernias were operated on by surgeons with sufficient experience. In 16 patients with concomitant abdominal disease we performed synchronous laparoscopic operations (15 cholecystectomies, 1 Meckel diverticulum resection). The average operation time was 112 minutes (52-195), in monolateral hernias during the learning curve, this was reduced to 57 minutes (40-125). The only conversion (0.08%) was necessary because of bowel injury, two early reoperations (0.16%) happened because of bowel perforation caused by electrocoagulation (laparotomy) and because of clipped nervus cutaneus femoris (clip laparoscopically removed). Sero-haematoma (86 = 7.1%) which is the most common mild complication did not occur after the introduction of routine pre-peritoneal drainage. Hydrocele, which developed in the remnant of the sac was operated on in 3 (0.25%) patients. This complication develops when the hernia sac could not be lifted laparoscopically into the abdominal cavity. This complication was eliminated when we removed the scrotal sac through a small skin incision at the end of the operation. Mean hospital stay was 3 (2-7) days, the mean return to normal activity 7-10 days. The majority (N=9) of 11 (0.9%) recurrences occurred in the learning curve. Our experience which is similar to what can be found in numerous other articles showed, that LH is beneficial (short hospitalisation, early return to normal activity, more favourable operability in bilateral and recurrent hernias, early recognition of contralateral occult hernias, performance of synchronous laparoscopic operations, small recurrence rate, improved surgical training) so it should be rightly considered as the gold standard of inguinal hernioplasties.

Adolescent↗

PubMed1996

Doppler transesophageal echocardiographic determination of aortic valve area in adults with aortic stenosis.

Two-dimensional transesophageal echocardiography has been shown to be an accurate method of measuring aortic valve area in patients with aortic stenosis. The accuracy of Doppler transesophageal echocardiography for this purpose is unknown. Thus 86 consecutive adult patients (mean age 68 +/- 11 years) with calcific (n = 79) or congenital bicuspid (n = 7) AS were studied by biplane or multiplane transesophageal echocardiography. From the transgastric long-axis view, continuous wave Doppler of peak aortic valve velocity and pulsed Doppler of left ventricular outflow tract velocity were determined. Left ventricular outflow tract diameter was measured from a transesophageal echocardiography long-axis view, and cross-sectional area was calculated. Aortic valve area was calculated by the continuity equation. Two-dimensional transesophageal echocardiography was used to directly measure aortic valve area by planimetry of the minimal orifice from a short-axis view. Aortic valve area determination was less feasible by Doppler (62 of 86 patients, or 72%) versus two-dimensional transesophageal echocardiography (81 of 86 patients, or 94%; p < 0.0025) because of the inability to align the continuous wave Doppler beam with the aorta in 24 patients. The feasibility of obtaining aortic valve area by Doppler transesophageal echocardiography improved from the first 43 patients (24 of 43 patients, or 56%) to the latter 43 patients (38 of 43 patients, or 88%; p < 0.0025) and suggests a significant learning curve. In 62 patients, aortic valve area by Doppler and two-dimensional transesophageal echocardiography did not differ (1.30 +/- 0.54 cm2 vs 1.23 +/- 0.46 cm2, p = not significant) and correlated well (r = 0.88; standard error of the estimate = 0.26 cm2; intercept = 0.02 cm2; slope = 1.04; p = 0.0001). Absolute and percent differences between aortic valve area measured by Doppler and two-dimensional transesophageal echocardiography were small (0.18 +/- 0.20 cm2 and 15% +/- 15%, respectively). Mild, moderate, and severe aortic stenosis by two-dimensional transesophageal echocardiography was correctly identified in 93% (28 of 30), 79% (15 of 19), and 77% (10 of 13) of patients by Doppler transesophageal echocardiography, respectively. Doppler transesophageal echocardiography is an accurate method to measure aortic valve area in patients with aortic stenosis and should complement two-dimensional transesophageal echocardiography. The feasibility of Doppler transesophageal echocardiography for aortic valve area determination has a significant learning curve.

Adult↗

PubMed2001

Laparoscopic radical nephrectomy in 100 patients: a single center experience from the United States.

BACKGROUND: The objective of the current study was to report a single-surgeon, single-center experience with 100 consecutive laparoscopic radical nephrectomies with intact specimen extraction, with the aim of evaluating the oncologic adequacy of the laparoscopic dissection from a technical standpoint and various parameters including the learning curve. METHODS: Of the 140 laparoscopic radical nephrectomies performed at the study institution since August 1997, the initial 100 are evaluated herein. To evaluate the technical oncologic adequacy, comparison was made with 40 contemporary open radical nephrectomy specimens with regard to detailed radiologic (computed tomography scan) and pathologic data. RESULTS: In the 100 patients studied (with a mean tumor size of 5.1 cm), the mean surgical time was 2.8 hours, the blood loss was 212 mL, the specimen weight was 554.3 g, and the hospital stay was 1.6 days. Complications occurred in 14 patients (14%) and were major in 3 (3%) and minor in 11 (11%). Two patients (2%) were converted to open surgery. There was no perioperative mortality. Over a mean follow-up of 16.1 months, there was no local or port site recurrence reported; 2 patients developed metastatic disease with 1 death occurring at 11 months. When evaluating the learning curve in the initial 50 versus the second 50 patients, a shorter surgical time (P = 0.02) appeared to be the only significant variable. On multivariate analyses, the only variables found to impact on surgical time were specimen weight (P < 0.001) and chronologic time period of surgery (P = 0.05). All laparoscopic specimens were extracted intact; surgical margins were negative for tumor in all 100 patients. All detailed radiologic and histopathologic parameters evaluated were nearly identical between the laparoscopic and open surgery groups. CONCLUSIONS: Laparoscopic radical nephrectomy with intact specimen extraction currently is a routine, effective, and efficacious treatment option for patients with T1-T3aN0M0 renal tumors. Although no long-term data were available as of last follow-up, the negative surgical margins achieved routinely in the current series provide encouraging surrogate evidence of the technical efficacy of laparoscopy from an oncologic standpoint. As such, at the study institution, laparoscopic radical nephrectomy with intact specimen extraction currently is the standard-of-care for patients with T1-3aN0M0 renal tumors measuring < or = 10-12 cm in size.

Adult↗

PubMed1996

Stimulated gracilis neosphincter operation. Initial experience, pitfalls, and complications.

PURPOSE: The stimulated gracilis neosphincter is accepted as a viable option in select patients with fecal incontinence. The aim of this study was to review the initial problems and complications. METHODS: A prospective analysis of all patients who underwent this procedure was undertaken. Stage I consisted of the distal vascular delay of the muscle and creation of a temporary stoma. Stage II was the transposition of the muscle and implantation of the stimulator and electrodes. Low frequency electrical stimulation was applied to the muscle for 12 weeks, after which Stage III (stoma closure) was undertaken. RESULTS: From March 1993 to December 1995, 17 patients (9 females and 8 males) with a mean age of 42.2 (range, 19-72) years underwent the procedure. One patient died from pancreatitis and another from small-bowel adenocarcinoma, three and six months after the procedure, respectively. Two patients (one with Crohn's disease) required permanent stomas. One additional patient required a permanent stoma because of lead fibrosis. Other complications noted during ascent of the learning curve included seroma of the thigh incision, excoriation of the skin above the stimulator, fecal impaction, anal fissure, parastomal hernia, rotation of the stimulator, premature battery discharge, fracture of the lead, perineal skin irritation, perineal sepsis, rupture of the tendon, tendon erosion, muscle fatigue during programming sessions, and electrode displacement from the nerve or fibrosis around the nerve. However, ultimately after rectification of these problems, 13 of the 15 eligible patients had stoma reversal. Manometric results showed an average basal pressure of 43 mmHg and an average maximum squeeze pressure that increased from 36 mmHg before surgery to 145 mmHg by stimulation (P < 0.01). Based on objective functional questionnaires, 9 of 15 (60 percent) evaluable patients reported improvement in continence, social interactions, and quality of life. Three of these nine patients require daily use of enemas. CONCLUSION: Although the stimulated gracilis operation is a feasible procedure for selected patients with severe incontinence, the learning curve is steep. Although the ultimate outcome in a selected group of patients can be very gratifying, major technical modifications are required before use beyond a research protocol setting. Furthermore, patients must have the psychological strength, emotional commitment, and financial resources that may be necessary for multiple revisional surgeries or ultimate device failure.

Adult↗

PubMed2000

Linear EUS for bile duct stones.

BACKGROUND: Radial scanning endoscopic ultrasonography (EUS) has been shown, in experienced hands, to be a safe and accurate means of detecting bile duct stones. We compared linear array EUS with endoscopic retrograde cholangiopancreatography (ERCP), in our first 50 cases, to evaluate efficacy of this examination as well as the learning curve for this indication. METHODS: A retrospective study was conducted on 50 patients with suspected choledocholithiasis. We compared results of EUS with those of ERCP as a reference. First a linear EUS examination was performed followed by ERCP, at a median interval of 31 days (range 3 to 162 days). RESULTS: The average age of patients was 56 years (range 26 to 76); 48% were women. Fifteen (30%) had undergone cholecystectomy, a mean of 8.5 years (range 1 to 22) before the EUS. EUS compared with ERCP had a 97% sensitivity, 77% specificity, and 90% accuracy. In 14% of patients EUS provided an additional or alternative diagnosis: chronic pancreatitis (n = 3), duodenitis (2), bile duct stricture (1), chronic gastritis (1). No complications were encountered due to EUS. CONCLUSIONS: We found in this early experience that linear array EUS is a reasonably safe and accurate means of detecting choledocholithiasis. Linear array EUS, despite the learning curve, seems to be about equivalent to radial EUS in accuracy. Appropriate use of this less invasive technique may possibly replace the use of diagnostic ERCP.

Cholangiopancreatography, Endoscopic Retrograde↗

PubMed2004

Endoscopic radial artery harvest for coronary artery bypass grafting: initial clinical experience.

BACKGROUND: Recently, an endoscopic technique was developed to harvest the radial artery (RA) via a 3-cm wrist incision in patients undergoing coronary artery bypass graft (CABG). The aim of this study was to evaluate our initial clinical experience with this technology. METHODS: Data were prospectively collected on 75 consecutive patients undergoing CABG with endoscopic RA harvest using the Ultra-Retractor (CardioVations, Somerville, NJ, USA) and the harmonic scalpel (Ethicon Endo-Surgery, Cincinnati, OH, USA). RESULTS: There were 66 men (88%) and 9 women (12%) with a mean age of 60 years (range, 31-77 years). Forty-eight (64%) of cases had non-elective surgery. Thirty-one (41%) of patients had diabetes. Sixty seven percent of the operations were performed on pump and 33% off pump. Average RA harvest time was 66 minutes (range, 25-120 minutes) with a significant learning curve (75 minutes for the first 20 cases and 63 minutes for the last 50 cases). Two (2.6 %) radial arteries were discarded, one because of extensive calcifications and the other because of damage to the conduit. No patients suffered death, perioperative myocardial infarction, or stroke. There was one reexploration of the forearm for a tunnel hematoma. Follow-up was achieved in 100% of patients and averaged 3.6 months (range, 0.5-13 months). Two patients died during the follow-up. There were no myocardial infarctions or reinterventions, with 96% of patients in functional class I /II. There were no motor deficits. There were no sensory deficits in the distribution of the lateral antebrachial cutaneous nerve, but transient mild dorsal thenar numbness or paresthesias were observed in 86% of patients. Cosmetic results were defined as good to excellent in 82% of patients. CONCLUSIONS: Short-term results of endoscopic RA harvest are excellent. There is a significant learning curve. Longterm follow-up as well as structural and functional assessments of the conduit are indicated.

Adult↗

PubMed2002

Direct coronary artery stenting without balloon predilation.

OBJECTIVE: Direct stenting of coronary stenosis without balloon predilation has shown to reduce the cost, the duration and the radiation exposure associated with the stenting of coronary artery stenosis. We sought to study the feasibility, safety and immediate learning curve of direct stenting in a Cardiac center in the Kingdom of Saudi Arabia. METHODS: We prospectively studied 76 consecutive patients with coronary artery stenoses who underwent direct stenting without balloon predilation. This study was carried out at King Fahad Armed Forces Hospital, Jeddah, Kingdom of Saudi Arabia, during the period January 2000 through to November 2001. Patients were selected by the operators based on reference vessel diameter >2.5 mm, absence of calcification, absence of vessel angulation and absence of total occlusion. RESULTS: Forty-six percent of the patients were diabetics, 34% had post infarction angina, and 60% underwent stenting of the left anterior descending artery. Most vessels (90%) were >3.0 mm in size. Direct stenting was successful in all patients and there were no deaths, no need for urgent bypass surgery, stent thrombosis or embolization. One patient developed a non-Q wave myocardial infarction. CONCLUSION: Direct stenting without balloon predilation is safe and feasible with almost no learning curve for interventionalists experienced in conventional coronary stenting and can be used for selected patients in centers without prior experience in direct stenting.

Catheterization↗

PubMed2004

Total pelvic exenteration with distal sacrectomy for fixed recurrent rectal cancer in the pelvis.

PURPOSE: This study evaluates the effectiveness of total pelvic exenteration with distal sacrectomy for fixed recurrent tumor that developed from primary rectal cancer. METHODS: We investigated surgical indications, techniques to minimize blood loss and reduce complications, and oncological outcomes in 57 patients who underwent total pelvic exenteration with distal sacrectomy between 1983 and 2001. RESULTS: Forty-eight patients (84 percent) had negative margins. A comparison between two periods (1983-1992 and 1993-2001) showed that mean blood loss decreased from 4,229 to 2,500 ml (P = 0.002), indicating a favorable learning curve in minimizing blood loss. Two hospital deaths were observed in the earlier period and none in the later period. The most common sacral amputation level was the S3 superior margin, followed by the S4 inferior margin and the S2 inferior margin. The most frequent complication was sacral wound dehiscence in 51 percent, followed by pelvic sepsis in 39 percent. The incidence of pelvic sepsis in the later period was significantly decreased to 23 percent, compared with 72 percent in the earlier period (P = 0.046). Multivariate analysis showed that negative margins and negative carcinoembryonic antigen predicted improved survival. In 48 patients with negative margins, three-year and five-year disease-specific survival rates were 62 percent and 42 percent, respectively. CONCLUSION: Strict patient selection makes total pelvic exenteration with distal sacrectomy a feasible radical approach for fixed recurrent tumor. Careful performance of this surgical procedure along with the proper steps to decrease blood loss should achieve a favorable learning curve and low rate of surgical complications.

Adult↗

PubMed2004

Prospective evaluation of factors influencing success rates of sentinel node biopsy in 814 breast cancer patients.

OBJECTIVE: This prospective multicenter study was performed to assess the reliability of sentinel lymph node (SLN) biopsy in breast cancer and to analyze factors potentially influencing success rates. METHODS: In 21 departments, SLN biopsy and consecutive axillary lymph node dissection were performed in 814 breast cancer patients. The 80 surgeons involved were free in the choice of lymphography technique. The detection rate and the sensitivity, as well as the impact of lymphography technique, patient selection, technical procedure and learning curves, were evaluated. RESULTS: The blue dye technique was used in 137 patients, radiocolloid in 169 patients, and combined blue dye/radiocolloid in 508 patients. The identification rate for the sentinel node was 83.9% for the entire group and showed a significant dependence on the lymphography technique (blue dye, 71.6%; radiocolloid, 78.8%; combined blue dye and radiocolloid, 89.6%). The overall sensitivity in detecting lymph node metastases was 91.3%. Immunostaining for cytoceratine revealed micrometastases in 19 (5.1%) of 374 patients in whom H/E staining was negative. The combined subdermal/peritumoral injection of the colloid showed a significantly higher identification rate than subdermal or peritumoral injection alone (96.8%, 84.6%, 78.6%; p < 0.001). There was also a significant higher detection rate in cases of SLN biopsy performed prior to lumpectomy, compared to SLN biopsy following lumpectomy (94.7% versus 82.8%; p < 0.001). Furthermore, there was a close correlation between the number of performed examinations and the detection rate. CONCLUSION: SLN mapping predicts the axillary lymph node status accurately. Learning curves and several technical features influence the detection rate significantly. However, the false negative rate was independent of experience and injection technique.

Adult↗

PubMed2004

Osteoid osteoma: factors for increased risk of unsuccessful thermal coagulation.

PURPOSE: To retrospectively identify risk factors that may impede a favorable clinical outcome after thermocoagulation for osteoid osteoma. MATERIALS AND METHODS: Informed consent (permission for the procedure and permission to use patient data for analysis) was obtained from all patients who met study criteria, and institutional review board did not require approval. Analysis included age, sex, size and location of osteoid osteoma, presence of calcified nidus, number of needle positions used for coagulation, coagulation time, accuracy of needle position, learning curve of radiologist, and previous treatment in 95 consecutive patients with osteoid osteoma treated with thermocoagulation. With chi(2) analysis, Fisher exact test, or unpaired Student t test and logistic regression analysis, 23 unsuccessfully treated patients were compared with 72 successfully (pain-free) treated patients. RESULTS: Parameters associated with decreased risk for treatment failure were advanced age (mean age, 24 years in treatment success group vs 20 years in treatment failure group) and increased number of needle positions during thermocoagulation. Estimated odds ratios were, respectively, 0.93 (95% confidence interval: 0.88, 0.99) and 0.10 (95% confidence interval: 0.02, 0.41). Patients with a lesion of 10 mm or larger seemed at risk for treatment failure (odds ratio = 2.68), but the 95% confidence interval of 0.84 to 8.52 included the 1.00 value. Needle position was inaccurate in nine of 23 patients with treatment failure; only one needle position was used in eight of these nine patients. Lesion location, calcification, sex, coagulation time, radiologist's learning curve, and previous treatment were not risk factors. CONCLUSION: Multiple needle positions reduce the risk of treatment failure in all patients and should especially, but not exclusively, be used in large (> or =10-mm) lesions or lesions that are difficult to engage to reduce the risk for unsuccessful treatment.

Adolescent↗

PubMed2002

Less invasive radial artery harvest.

BACKGROUND: Recent studies have sparked a renewed interest in the use of autogenous radial arteries in coronary operations. Some concerns have been found about sequelae of conventional harvesting. A less invasive technique for radial artery harvesting has been proposed by others using endoscopic devices. This technique is time consuming, needs expensive instrumentation and an important learning curve. METHODS: A new less invasive approach for radial harvesting has been developed with a light assisted retractor under direct vision. A small skin incision, median in the forearm, is followed by dissection of the proper plane of the artery. A subcutaneous tunnel is created around the vessel and all the branches are ligated or clipped. The dissection of the pedicle under the skin is completed with the aid of a modified light assisted retractor, originally designed for the saphenous vein harvesting. The incision is closed after heparin reversal with a small redon as drainage. RESULTS: A preliminary serie of 15 patients have been operated with this technique. In all patients the radial artery was patent and functional at the postoperative angiography. Morbidity included only a light hematoma at the beginning of our experience. CONCLUSION: This less invasive technique for the radial artery harvesting appears to be an excellent surgical compromise between the open technique and the endoscopic procedure; it is easy to perform, the learning curve is acceptable and it offers an excellent aesthetic result.

Dissection↗

PubMed1999

Small incision nucleus capture: results of 200 cases.

PURPOSE: To compare the learning curve in a series of 200 cataract surgeries performed using small incision nucleus capture with that of phacoemulsification as reported in the literature. SETTING: Department of Ophthalmology, University of Genoa, Genoa, Italy. METHODS: Two hundred eyes of 163 consecutive patients with cataract had small incision nucleus capture, a relatively new cataract surgery technique that allows small incisions and in-the-bag intraocular lens implantation. Patients were divided into 4 groups of 50 each according to when they had surgery between August 1996 and October 1997. The incidence of intraoperative complications (capsule break with or without vitreous loss, capsulorhexis tears, Descemet's detachment, transient iris damage) and postoperative complications (raised intraocular pressure, corneal epithelial edema, Descemet's folds, and permanent iris damage) were evaluated at the different time points. Also recorded was final visual acuity. These results were compared with those obtained with phacoemulsification. RESULTS: The study comprised 92 women and 71 men with an age range of 41 to 93 years. Overall final results showed that the learning curve of nucleus capture is comparable to that of phacoemulsification. CONCLUSION: Nucleus capture cataract extraction resulted in a low incidence of complications and good visual recovery that was comparable to that obtained with phacoemulsification.

Adult↗

PubMed2000

Effect of time delay on surgical performance during telesurgical manipulation.

BACKGROUND: Telementoring allows a less experienced surgeon to benefit from an expert surgical consultation, reducing cost, travel, and the learning curve associated with new procedures. However, there are several technical limitations that affect practical applications. One potentially serious problem is the time delay that occurs any time data are transferred across long distances. To date, the effect of time delay on surgical performance has not been studied. MATERIALS AND METHODS: A two-phase trial was designed to examine the effect of time delay on surgical performance. In the first phase, a series of tasks was performed, and the numbers of robotic movements required for completion was counted. Programmed incremental time delays were made in audiovisual acquisition and robotic controls. The number of errors made while performing each task at various time delay intervals was noted. In the second phase, a remote surgeon in Baltimore performed the tasks 9000 miles away in Singapore. The number of errors made was recorded. RESULTS: As the time delay increased, the number of operator errors increased. The accuracy needed to perform remote robotic procedures was diminished as the time delay increased. A learning curve did exist for each task, but as the time delay interval increased, it took longer to complete the task. CONCLUSIONS: Time delay does affect surgical performance. There is an acceptable delay of <700 msec in which surgeons can compensate for this phenomenon. Clinical studies will be needed to evaluate the true impact of time delay.

Evaluation Studies as Topic↗

PubMed1996

Laparoscopic hernia repair--what are the results?

The two widely practised laparoscopic groin hernia repairs are: a) trans-abdominal preperitoneal (TAPP) and b) trans-extraperitoneal preperitoneal (TEPP) approaches. Early results are encouraging with both the techniques being associated with low recurrence rates (0% to 2%) comparable to the best, reported for standard open repair (Shouldice and Lichtenstein's). Other complications are higher in the beginning following laparoscopic hernia repair compared to the conventional method. These complications are related to the learning curve and expected to come down significantly with increasing experience of surgeons. Laparoscopic repair of recurrent groin hernia appears to be considerably superior to the conventional technique. The recurrence rates following conventional repair of recurrent groin hernias are between 1.5% and 35% (Table I) compared to none for laparoscopic repair of recurrent inguinal hernias. The disadvantages of laparoscopic repair include greater technical difficulty, higher incidence of serious complications and increased cost. Sutured open repair is associated with high postoperative discomfort, greater difficulty of repairing recurrent hernia with higher societal cost (due to prolonged time-off from work for 12% to 57% of patients operated for various open technique-Table II). The techniques of laparoscopic hernia repairs are nearly standardised today. Laparoscopic surgeons have an obligation to offer the new alternative and to ensure that it is safely used. Laparoscopic repair is another technique used for the repair of inguinal hernias, which is going to stay as a safe and effective alternative to open repair as the learning curve is over. There is an urgent need to have well-designed prospective randomised trials in the near future.

Hernia, Inguinal↗

PubMed2002

One versus two proficient laparoscopic surgeons for laparoscopic live donor nephrectomy.

OBJECTIVES: To compare the laparoscopic donor nephrectomy (LDN) results obtained by two different surgical teams, one consisting of a proficient laparoscopic surgeon assisted by an inexperienced laparoscopic surgeon and another consisting of two proficient laparoscopic surgeons. With more centers embarking on LDN programs, it is important to identify the factors that can improve overall outcomes during the initial learning curve. METHODS: A retrospective review was performed of the initial 70 sequential LDNs performed between October 1998 and March 2001 at our institutions. The procedures were stratified into two groups. Group 1 consisted of LDN cases performed by one proficient laparoscopic surgeon and an inexperienced laparoscopic surgeon (resident, fellow, or faculty) as the first assistant; group 2 consisted of cases performed by two proficient laparoscopic surgeons. RESULTS: Twenty-six LDNs were performed by group 1 and 44 by group 2. The total operative time and estimated blood loss showed a statistically significant decrease in group 2 compared with group 1, 143 +/- 32 minutes versus 218 +/- 38 minutes (P <0.001) and 92 +/- 115 mL versus 158 +/- 148 mL (P = 0.044), respectively. Two major complications occurred in group 1 (7.7%) and two major complications occurred in group 2 (4.5%). The 3-month postoperative recipient creatinine levels were similar for both groups, 1.6 +/- 1.3 versus 1.4 +/- 0.4 (P = 0.408). CONCLUSIONS: A surgical team composed of two proficient laparoscopic surgeons during the early learning curve of LDN may allow safe and efficient development of a laparoscopic live donor renal transplantation program.

Clinical Competence↗

PubMed2000

Total endoscopic computer enhanced coronary artery bypass grafting.

OBJECTIVE: In an effort to minimize access in coronary artery bypass (CAB) surgery, a total endoscopic approach using computer enhanced technology was developed. METHODS: By July 1999 the da Vinci telemanipulation system (Intuitive Surgical, Mountain View, CA) was used in 66 patients with coronary artery disease. In 12 patients undergoing routine coronary artery bypass grafting (CABG) (group 1) the internal thoracic artery (ITA) to left anterior descending artery (LAD) anastomosis was performed remotely using the system. In 32 patients (group 2) endoscopic dissection of the ITA was performed followed by a conventional minimally invasive direct coronary artery bypass (MIDCAB) operation. In 22 patients (group 3) the complete operation was performed endoscopically through 4 ports (total endoscopic coronary artery bypass, TECAB). Port-Access cardiopulmonary bypass with cardioplegic arrest was used for TECAB. RESULTS: In group 1 the time for performing the ITA to LAD anastomosis was 17 +/- 10 min. Mean graft flow was 38 +/- 25 ml/min. One anastomosis leaked and was repaired manually. In group 2 in 31/32 patients (96%) the ITA harvest was successfully performed with the system at mean of 61 +/- 27 min. There was a substantial learning curve associated with ITA take-down. In one patient a dissection caused insufficient free ITA graft flow which necessated additional vein grafting. Postoperative angiography demonstrated graft patency in all cases. In the TECAB group, the operation could be completed through four ports in 18 of the 22 patients (82%) with operating times in the range 220-507 min. In four patients, elective conversion to a minithoracotomy was required due to failure to identify the LAD (1), bleeding from the anastomosis (1), grafting of a diagonal branch (1) and torsion of the pedicle (1). One patient required reoperation for bleeding from an ITA side-branch. Median intubation time was 13 h and stay on ICU and hospitalization were 20 h and 7 days, respectively. A 3-month follow-up angiography revealed patent grafts in all TECAB patients. CONCLUSION: Endoscopic ITA harvesting and performing of arterial anastomoses can be safely performed with the da Vinci system. TECAB is possible on the arrested heart with good functional results. However, a substantial learning curve has to be overcome which is reflected in long operation times and an initial significant conversion rate.

Cardiopulmonary Bypass↗