Biomedical subjects

N Stergiou

Publications and source records attributed to N Stergiou.

At least 19 recordsLinked to original sources

PubMed2006

Robotic surgery and training: electromyographic correlates of robotic laparoscopic training.

BACKGROUND: Robotic laparoscopic surgery has been shown to decrease task completion time, reduce errors, and decrease training time, as compared with manual laparoscopic surgery. However, current literature has not addressed the physiologic effects, in particular muscle responses, to training with a robotic surgical system. The authors seek to determine the frequency response of electromyographic (EMG) signals of specific arm and hand muscles with training using the da Vinci Surgical System. METHODS: Seven right-handed medical students were trained in three tasks with the da Vinci Surgical System over 4 weeks. These subjects, along with eight control subjects, were tested before and after training. Electromyographic (EMG) signals were collected from four arm and hand muscles during the testing sessions, and the median EMG frequency and bandwidth were computed. RESULTS: The median frequency and frequency bandwidth both were increased after training for two of the three tasks. CONCLUSION: The results suggest that training reduces muscle fatigue as a result of faster and more deliberate movements. These changes occurred predominantly in muscles that were the dominant muscles for each task, whereas the more demanding task recruited more diverse motor units. An evaluation of the physiologic demands of robotic laparoscopic surgery using electromyography can provide us with a meaningful quantitative way to examine performance and skill acquisition.

Adult↗

PubMed2006

Intraductal ultrasonography in the diagnosis of Mirizzi syndrome.

BACKGROUND AND STUDY AIMS: Common bile duct (CBD) compression can be caused by stones in the cystic duct (Mirizzi syndrome) which can be difficult to diagnose even with endoscopic retrograde cholangiopancreatography (ERCP). Conventional imaging often gives insufficient information and endoscopic ultrasonography (EUS) and magnetic resonance imaging may improve diagnostic accuracy, but often the final diagnosis is made during exploratory surgery. PATIENTS AND METHODS: All patients undergoing ERCP during a 3-year period were prospectively analyzed if they fulfilled the inclusion criteria: gallbladder in situ; obstructive jaundice with CBD stenosis, demonstrated at endoscopic retrograde cholangiography (ERC), but unexplained at ultrasonography; and inability to demonstrate the cystic duct during ERC. Intraductal ultrasonography (IDUS) was carried out over a guide wire using a 20-MHz probe. Prior to ERCP, patients were evaluated with abdominal ultrasonography and computed tomography (CT), as well as by magnetic resonance cholangiopancreatography (MRCP) or EUS in some. RESULTS: 74 patients out of 2089 undergoing ERCP fulfilled the entry criteria. Final diagnoses, from surgical exploration (n = 41), cytology (n = 21), or endoscopic extraction of stones from the cystic duct (n = 12), were Mirizzi syndrome (type I) in 30 patients and other causes in 44 patients (gallbladder carcinoma [n = 16], pancreatic carcinoma [n = 9], metastatic compression [n = 9], other [n = 10]). CT had shown suspected Mirizzi syndrome in 1/30 cases (3 %) and MRCP in 12/19 evaluated cases (63 %). EUS allowed a correct diagnosis in 11 of 15 evaluated cases (73 %). IDUS required an additional 8 +/- 3 min and showed a sensitivity of 97 % and specificity of 100 %. CONCLUSION: IDUS is a sensitive and specific method for the diagnosis of Mirizzi syndrome.

Aged↗

PubMed2005

Robotic surgery training and performance: identifying objective variables for quantifying the extent of proficiency.

BACKGROUND: To understand the process of skill acquisition in robotic surgery and to allow useful real-time feedback to surgeons and trainees in future generations of robotic surgical systems, robotic surgical skills should be determined with objective variables. The aim of this study was to assess skill acquisition through a training protocol, and to identify variables for the quantification of proficiency. METHODS: Seven novice users of the da Vinci Surgical System engaged in 4 weeks of training that involved practicing three bimanual tasks with the system. Seven variables were determined for assessing speed of performance, bimanual coordination, and muscular activation. These values were compared before and after training. RESULTS: Significant improvements were observed through training in five variables. Bimanual coordination showed differences between the surgical tasks used, whereas muscular activation patterns showed better muscle use through training. The subjects also performed the surgical tasks considerably faster within the first two to three training sessions. CONCLUSIONS: The study objectively demonstrated that the novice users could learn to perform surgical tasks faster and with more consistency, better bimanual dexterity, and better muscular activity utilization. The variables examined showed great promise as objective indicators of proficiency and skill acquisition in robotic surgery.

Adult↗

PubMed2005

Reduction of miss rates of colonic adenomas by zoom chromoendoscopy.

BACKGROUND AND AIMS: The aim of this study was to determine the detection rate of polyps using zoom chromoendoscopy (ZE) compared with standard video colonoscopy. PATIENTS AND METHODS: End-to-end colonoscopies were performed in 50 patients by two different endoscopists blinded for each other's results. Lesions detected during initial standard colonoscopy (C1) were biopsied or removed by snare resection. The second colonoscopy (C2) was done with a zoom colonoscope spraying the whole colon with indigocarmine (0.4%). In addition, detected mucosal lesions were documented prior to ZE and then classified according to the pit pattern classification before biopsy or removal. The retrieval time for each procedure was determined. RESULTS: The average retrieval time for C1 was 13+/-9 min (9-24) and 28+/-11 min (16-38, p<0.05) for ZE. During C1, 56 lesions were detected in 26 of 50 patients (34 hyperplastic and 22 adenomatous). During C2, 19 additional polyps were documented prior to ZE (15% tandem miss rate), and 20 further lesions were detected with ZE (21% additional polyp detection rate compared to C1 and C2 without ZE). Of the 39 additional lesions removed during C2 after ZE, 29 were hyperplastic and 10 were adenomatous. Most adenomas detected during the second investigation were found in patients in whom adenomatous polyps had already been removed during the initial colonoscopy (9 of 26 patients vs 1 of 24 patients, p<0.02). No carcinoma was detected. The pit pattern classification allowed a correct differentiation between hyperplastic and adenomatous polyps (accuracy 93%, sensitivity 90%, specificity 97%). CONCLUSION: Using zoom chromoendoscopy, the rate of detecting colonic polyps can be increased at the cost of a longer retrieval time.

Adenoma↗

PubMed2005

Electromechanical delay of the knee extensor muscles is not altered after harvesting the patellar tendon as a graft for ACL reconstruction: implications for sports performance.

Although the scar tissue, which heals the donor site defect, has different elasticity from the neighbouring patellar tissue, it remains unclear if this scar tissue can lead to the changes of the electromechanical delay (EMD) of the knee extensor muscles. If such changes do exist, they can possibly affect both the utilization of the stored energy in the series elastic component, as well as the optimal performance of the knee joint movement. The purpose of this study was to investigate the influence of harvesting the patellar tendon during anterior cruciate ligament (ACL) reconstruction and the associated patellar tendon scar tissue development on the EMD of the rectus femoris (RF) and vastus medialis (VM) muscles. Seventeen patients who underwent an ACL reconstruction using the medial third of the patellar tendon were divided in two groups based upon their post-operative time interval. Maximal voluntary contraction from the knee extensors, surface EMG activity, and ultrasonographic measurements of the patellar tendon cross-section area were obtained from both knees. Our results revealed that no significant changes for the maximal voluntary contraction of the knee extensors and for the EMD of the RF and the VM muscles due to patellar scar tissue development after harvesting the tendon for ACL reconstruction. The EMD, as a component of the stretch reflex, is important for the utilization of the stored energy in the series elastic component and thus, optimal sports performance. However, from our results, it can be implied that the ACL reconstruction using a patellar tendon graft would not impair sports performance as far as EMD is concerned.

Adult↗

PubMed2005

Detecting altered postural control after cerebral concussion in athletes with normal postural stability.

OBJECTIVE: To determine if approximate entropy (ApEn), a regularity statistic from non-linear dynamics, could detect changes in postural control during quiet standing in athletes with normal postural stability after cerebral concussion. METHODS: The study was a retrospective, case series analysis of centre of pressure (COP) data collected during the Sensory Organization Test (SOT) from NCAA Division I (USA) athletes prior to and within 48 h after injury. Subjects were 21 male and six female athletes from a variety of sports who sustained a cerebral concussion between 1997 and 2003. After injury, athletes displayed normal postural stability equivalent to preseason levels. For comparison, COP data also were collected from 15 male and 15 female healthy non-athletes on two occasions. ApEn values were calculated for COP anterior-posterior (AP) and medial-lateral (ML) time series. RESULTS: Compared to healthy subjects, COP oscillations among athletes generally became more regular (lower ApEn value) after injury despite the absence of postural instability. For AP time series, declines in ApEn values were much larger in SOT conditions 1 and 2 (approximately three times as large as the standard error of the mean) than for all other conditions. For ML time series, ApEn values declined after injury in all sensory conditions (F(1,55) = 6.36, p = 0.02). CONCLUSIONS: Athletes who demonstrated normal postural stability after concussion nonetheless displayed subtle changes in postural control. Changes in ApEn may have represented a clinically abnormal finding. ApEn analysis of COP oscillations may be a valuable supplement to existing concussion assessment protocols for athletes.

Adolescent↗

PubMed2005

Joint kinetics of the ankle and knee when running over obstacles.

AIM: When running over obstacles of increasing height, heelstrike (HS) runners switch to a forefoot (FF) landing pattern once a critical obstacle height is reached. The primary purpose of this study was to determine whether ankle or knee joint kinetic variables trigger the gait change from a HS to a FF striking pattern as obstacle height increases. METHODS: Ten subjects were filmed from the sagittal plane as they ran at their preferred running speed over a force platform during 6 obstacle height conditions ranging from 10% to 22.5% of standing height, as well as an additional baseline condition with no obstacle (0%). An inverse dynamics approach was utilized to calculate ankle and knee joint kinetics at each condition. RESULTS: Differences in joint kinetics did not occur until a height was reached at which the landing strategy changed from a HS to a FF landing pattern. Most differences occurred at the ankle joint, at which there was a greater maximum plantar flexor moment and a greater amount of energy absorbed when obstacles of sufficient height to require a FF landing pattern were negotiated. CONCLUSIONS: Although no variables were found which met all of the criteria necessary to be considered a determinant of the gait transition, there were variables which distinguished between a HS and FF strike landing pattern as obstacle height increased.

Adult↗

PubMed2004

Endoscopic resection of submucosal esophageal tumors: a prospective case series.

BACKGROUND AND STUDY AIM: The introduction of endoscopic ultrasound (EUS) and endoscopic mucosal resection has offered a new alternative to simple observation or surgical resection for the management of esophageal submucosal tumors. PATIENTS AND METHODS: During a 4-year period, endoscopic resection was attempted in 20 consecutive patients (nine women, 11 men; mean age 52 +/- 10 years) with esophageal submucosal tumors < 4 cm in size, confirmed by endoscopy and miniprobe EUS (20 MHz). The mean tumor diameter was 17 +/- 8 mm (8 - 34 mm). Prior EUS-guided cytological examination revealed benign tumors in 11 patients; however, endoscopic resection was attempted in most patients for diagnostic purposes also. Several patients were symptomatic (retrosternal pain, n = 4; dysphagia, n = 4; recurrent bleeding, n = 2) but most tumors had been detected incidentally. RESULTS: In the majority of patients the tumor was ligated with a rubber band and then resected with a snare (n = 11), and in the others simple snare resection ("lift-and-cut," n = 7) or cap resection (n = 2) was done. A macroscopically complete endoscopic resection was achieved in 19/20 patients, and the remaining patient was managed surgically. Endoscopic hemostasis was necessary (and successful) in eight patients (40 %), but blood transfusion was not required. No other side effects occurred. Histological examination revealed granular cell tumor in 12 patients, leiomyoma in six patients, and a lipoma and stromal tumor in one patient each. Histologically, all tumors were judged to be benign and a microscopically complete resection (R0) was achieved in all patients, with the exception of the one patient with a stromal tumor. Thus, surgical resection was necessary in only two of the 20 patients (10 %). During the median prospective follow-up of 12 months no tumor recurrence was detected in any patient. CONCLUSION: Endoscopic resection of esophageal submucosal tumors is safe and effective. The probability of achieving curative resection (R0 resection, histologically benign) is high especially if the tumors are smaller in size (< 4 cm).

Endoscopy↗

PubMed2003

The effects of anterior cruciate ligament reconstruction on tibial rotation during pivoting after descending stairs.

Recent in vitro research suggests that ACL reconstruction does not restore tibial rotation. This study investigated rotational knee joint stability in vivo during a combined descending and pivoting movement that applies a high rotational load to the knee joint. We studied 20 ACL reconstructed patients (bone-patellar tendon-bone graft) and 15 matched controls with a six-camera optoelectronic system performing the examined movement. In the control group the results showed no significant differences in the amount of tibial rotation between the two sides. No significant differences were also found between the contralateral intact leg of the ACL group and the healthy control. However, a significant difference was found within the ACL reconstructed group and between the reconstructed and the contralateral intact leg. Therefore ACL reconstruction may not restore tibial rotation even though anterior tibial translation has been reestablished.

Adult↗

PubMed2003

Staging of colonic neoplasms by colonoscopic miniprobe ultrasonography.

BACKGROUND AND AIMS: In contrast to the situation in the upper gastrointestinal tract staging of colonic neoplasm by endoscopic ultrasonography (EUS) has not gained importance because until yet preoperative staging is without any clinical consequences. This may change with the introduction of minimally invasive surgical procedures and endoscopic resection techniques as an alternative to conventional (open) surgery. PATIENTS AND METHODS: We performed EUS with a miniprobe in 54 consecutive patients with colonic tumors who had been referred to our hospital for endoscopic resection or for laparoscopic resection of their lesions. Therefore patients with locally advanced tumors or systemic tumor spread were not included. After detection of the lesion during colonoscopy miniprobe EUS was performed with water-filling of the colonic lumen. The depth of invasion (T classification) and the local lymph node status (positive or negative) was ascertained. Lymph node-negative lesions staged as T1 underwent endoscopic resection whenever this was technically possible. In lymph node-negative T2-3 tumors laparoscopic resection was planned if they were localized at least 10 cm apart from the flexuras. All other lesions were resected by open surgery. The EUS findings were later compared with the final pathological results (pTN classification) of the resected specimen. RESULTS: In 50 patients (93%) a sufficient EUS evaluation of the colonic tumor was possible. In one patient with a tumor at the left flexura the lesion could not be completely visualized, and in three patients a sufficient water filling of the colon was impossible. The infiltration depth was correctly classified in 17 adenomas, 16 T1, 8 T2, 5 T3, and one T4-carcinoma (EUS accuracy for T staging: 94%). Two T2 and one T3 carcinoma were overstaged by EUS while no understaging was recorded. The lymph node status was correctly classified in 42/50 patients (84%), and a false-negative lymph node status was found in only 4/50 cases (8%). The overall accuracy of EUS was 80%. CONCLUSION: Miniprobe EUS is suitable and has a sufficient but not optimal accuracy for staging of colonic neoplasm. Its employment makes sense if minimally invasive resection techniques in patients with high-risk for open surgery are planned.

Adenoma↗

PubMed2003

[Clinical value of intraductal ultrasonography for clarification of confusing ERCP results].

OBJECTIVE: This study assesses the value of intraductal ultrasound (IDUS) when the findings of endoscopic retrograde cholangio-pancreatography (ERCP) are unclear. PATIENTS AND METHODS: IDUS was performed over a two-year period in cases of bile duct or pancreatic duct stenosis of unknown origin found during ERCP or if cholelithiasis was suspected but ERC was seemingly normal. Duct stenoses were classified,before and after IDUS, as benign or malignant ductal or malignant extraductal, the findings then being checked by clinical follow-up,histology or, if bile duct stones had been suspected, by instrumental bile duct exploration. RESULTS: Among 1303 ERCP investigations IDUS was attempted in 125 patients (9.6%; average age 60+/-14 years; 62 females). IDUS failed in seven patients for technical reasons (failure rate 6%). IDUS took an average time of 9+/-3 min. ERCP plus IDUS provided correct classification in 52 of 60 patients with bile duct stenosis (87%), and in 14 of 16 (88%) patients with pancreatic duct stenosis.ERCP alone correctly classified duct stenosis in 54 of 76 patients(87%), but in 66 of 76 (87%) with additional IDUS. The correct demonstration or exclusion of choledocholithiasis was obtained by IDUS in 40 of 42 patients (95%). Thus IDUS changed the diagnosis made by ERCP in 28 of 118 patients (24%). CONCLUSION: With minor expenditure of time and an acceptable failure rate, additional IDUS after ERCP increases the diagnostic accuracy in cases where ductal stenosis or bile duct stones have not been clearly demonstrated.

Adenocarcinoma↗

PubMed2003

Spanning set defines variability in locomotive patterns.

The purpose of the investigation was to use the spanning set methodology to quantify variability in locomotive patterns and to compare this method with traditional measures of variability. Subjects ran on a treadmill while sagittal plane kinematic data were collected with a high-speed (180 Hz) camera. Changes in variability were evaluated as the subject ran barefoot and in shoes. Mean ensemble curves for the knee angle during the stance period were created for each condition. From these curves, traditional measures of variability were calculated using the coefficients of variation (CVs), and the mean deviation (MD). Spanning set vectors were defined from the coefficients of polynomials that were fitted to the respective standard deviation curves. The magnitude of the spanning set was determined by calculating the norm of the difference between the two vectors. The normalised difference between the two conditions was 6.6%, 6.9% and 98%, for the MD, CV and spanning sets, respectively. The results indicated that the spanning set was capable of statistically (p < 0.05) determining differences in variability between the two conditions. CV and MD measures were unable to detect statistical differences (p > 0.05) between the two conditions. The spanning set provides an alternative, and sensitive measure for evaluating differences in variability from the mean ensemble curve.

Adult↗

PubMed2003

Reduced risk for pancreatitis after endoscopic microtransducer manometry of the sphincter of Oddi: a randomized comparison with the perfusion manometry technique.

BACKGROUND AND STUDY AIMS: Endoscopic microtransducer manometry of the sphincter of Oddi has been shown to be a reliable alternative to perfusion manometry for evaluating sphincter of Oddi motor function. It avoids volume loading of the biliopancreatic system, and may therefore be associated with a lower risk of inducing postmanometry pancreatitis.[nl] PATIENTS AND METHODS: During a 2-year period, microtransducer manometry of the sphincter of Oddi was carried out in 215 patients (median age 42 years; 155 women; biliary study in 152 cases, additional pancreatic evaluation in 63 cases). Sphincter of Oddi manometry was conducted as the sole procedure in all patients. The frequency of pancreatitis was assessed prospectively and graded according to established guidelines. A total of 130 consecutive patients (median age 37 years, 92 women; 30 with biliary type II, 58 with type III, 34 with pancreatic type I, and eight with type II) were then randomly assigned to undergo microtransducer or perfusion manometry of the sphincter of Oddi in a standardized fashion. RESULTS: During the initial 2-year period, nine cases of pancreatitis (a pancreatitis frequency of 4.2 %) were observed after microtransducer manometry, and most were of mild degree (six mild, two moderate, and one severe). No deaths occurred, and no surgical procedures were required. In the randomized part of the study, the demographic and clinical characteristics of the patients in both groups, as well as the technical aspects of the procedures performed, were well matched. The frequency of pancreatitis after microtransducer manometry was 3.1 %, compared with 13.8 % after perfusion manometry ( P < 0.05). Pancreatitis occurred in two patients after microtransducer manometry, and was mild in both cases. After perfusion manometry, mild pancreatitis occurred in six patients and moderate pancreatitis in three. CONCLUSION: Endoscopic microtransducer manometry of the sphincter of Oddi is associated with a lower risk for postmanometry pancreatitis than standard perfusion manometry.

Adult↗

PubMed2003

Subtalar and knee joint interaction during running at various stride lengths.

AIM: It has been suggested that during running proper coordination between subtalar pronation/supination and knee flexion/extension via tibial rotation is important to attenuate ground reaction impact forces (GRIF). Lack of coordination over time may produce a wide range of injuries. It was hypothesized that increasing stride length would result in higher GRIF. It was also hypothesized that alterations in stride length would result in changes of the subtalar/knee coordination. METHODS: Six subjects ran under 3 different stride lengths (normal stride, understride and overstride) at their self-selected pace. Sagittal, rear view kinematic data and GRIF kinetic data were collected. The subtalar/knee coordination was evaluated via timing and relative velocity measures. Repeated measures ANOVA were performed on these measures with a Tukey post-hoc analysis conducted where appropriate (p<0.01). RESULTS: Increased stride length produced significant increases in GRIF and significantly augmented the differences between rearfoot and knee angular velocities. A change in the rearfoot angle curve from a unimodal (1 minimum) to a bimodal (2 minimums) parabolic configuration was also observed. The appearance of the additional minimum was attributed to the increased impact with the ground. CONCLUSION: The results indicated that increases in GRIF via changes in stride length could disrupt the coordination between subtalar and knee joint actions.

Adult↗

PubMed2002

Endoscopic snare resection of large colonic polyps: how far can we go?

BACKGROUND AND AIMS: Colonoscopic polypectomy is preventing colorectal cancer. Videoendoscopy and new perendoscopic hemostasis techniques make endoscopic polypectomy of large colonic polyps an alternative to the surgical approach. This study examined whether complete snare resection of giant colonic polyps is feasible and safe and for determining how often surgery is necessary due to invasive cancer detected histologically after polypectomy. PATIENTS AND METHODS: The study included 59 consecutive patients with 68 colonic polyps larger 30 mm in diameter. Snare polypectomy was performed after an endoscopic ultrasound with a miniprobe found no sign of invasive, or, depending on the appearance of the polyp, a bleeding prophylaxis had been carried out. Acute procedural or delayed bleeding was treated endoscopically. RESULTS: Of the 68 polyps 26, mostly pedunculated were resected en bloc (38%) and histologically ensured as completely resected; 42 polyps had to be resected by piecemeal technique (62%). Piecemeal resection was performed significantly more often in sessile polyps (38/41, 93%) than in pedunculated polyps (4/27, 15%, P<0.01). Follow-up colonoscopy after 3 months showed remaining adenomatous tissue of piecemeal-resected polyps in 12 cases (28%), which were 12 resected sessile polyps (29%) and no case of resected pedunculated polyp. To achieve complete resection of sessile polyps a second procedure was necessary significantly more often than for resection of pedunculated polyps (12 cases in sessile polyps, 18% vs. no case in pedunculated polyps). Remaining adenomatous tissue was removed in all 12 cases during the first follow-up colonoscopy after 3 months, confirmed by a biopsy 6 months after the initial procedure. Overall coexisting malignancy was found in only 7 polyps (12%). Due to high-risk factors only one of them underwent secondary surgical procedure. CONCLUSION: The present study shows that endoscopic snare resection of giant colonic polyps is a safe procedure, and that secondary operative measures for managing coexisting malignancy are rarely necessary.

Adenomatous Polyps↗

PubMed2001

A dynamical systems investigation of lower extremity coordination during running over obstacles.

OBJECTIVE: To investigate intralimb coordination during running over a level surface and over obstacles of three different heights. DESIGN: The phasing relationships between the foot and leg motions in the frontal plane, and the shank and thigh motions in the sagittal plane were used to compare patterns of coordination. BACKGROUND: The coordinated actions of lower extremity segments are necessary to absorb the impact forces generated during running. The behavioral patterns of these segments can be studied under changing task demands using analysis techniques from the Dynamical Systems Theory. METHODS: Ten subjects ran at their self-selected pace under four conditions: over a level surface and over obstacles of different heights (5%, 10%, 15% of their standing height). A force platform was used to record impact forces during landing after obstacle clearance, while kinematics were collected using a two-camera system. RESULTS: The increases in obstacle height resulted in significant changes in impact forces (34% increase between the two extreme conditions) and more in-phase relationships between the segments during early stance. No changes were observed in the variability of the phasing relationships. CONCLUSIONS: The coordination changes observed might be compensatory strategies aimed to reduce forces and potential injury. However, since the impact forces still increased significantly, it is also possible that the observed changes might be at-risk movement patterns predisposing runners to injury.

Adult↗

PubMed2001

Intralimb coordination following obstacle clearance during running: the effect of obstacle height.

The purpose of this study was to investigate the different coordination strategies used following obstacle clearance during running. Ten subjects ran over a level surface and over obstacles of six different heights (10, 12.5, 15, 17.5, 20 and 22.5% of their standing height). Analysis based upon the dynamical systems theory (DST) was used and the phasing relationships between lower extremity segments were examined. The results demonstrated that the increasing obstacle height elicited behavioral changes. The foot and the leg became more independent in their actions, while the leg and the thigh strengthened their already stable relationship. The 15% obstacle height seems to be a critical height for the observed changes.

Adult↗

PubMed2001

Topical application of nitrates onto the papilla of Vater: manometric and clinical results.

BACKGROUND AND STUDY AIMS: Systemic administration of nitrates inhibits motility of the sphincter of Oddi (SO) but is hampered by a decrease of the arterial blood pressure. We evaluate whether topical application of glyceril trinitrate (GTN) onto the papilla can facilitate cannulation of the common bile duct during routine endoscopic retrograde cholangiopancreatography (ERCP) and compare the effect of topical GTN with that of isosorbide dinitrate (ISDN) on SO motility. PATIENTS AND METHODS: A total of 80 patients undergoing routine ERCP for suspected biliary obstruction received topical application of either saline (n = 40) or 10 mg of GTN (n = 40) onto the papilla of Vater in a randomized, double-blind fashion. Thereafter, selective bile-duct cannulation was attempted with a 0.035" hydrophilic guide wire. In another trial, 16 biliary type III patients underwent endoscopic SO-manometry and received in a randomized fashion either 10 mg of GTN (n = 8) or 10 mg of ISDN (n = 8) which was infused topically onto the papilla via the manometric catheter. Thereafter, the manometric recording was continued for a further 5 minutes. RESULTS: A spontaneous opening of the papilla with concurrent transpapillary bile flow was observed in 24/40 patients after topical GTN, and in only 8/40 patients after topical saline (P < 0.01). However, neither the number of cannulation attempts nor the time until successful cannulation differed significantly between the groups. In addition, the pre-cut rate was nearly identical in the two groups. Topical GTN showed no significant influence on the mean arterial blood pressure. The SO-baseline pressure was significantly lowered by topical GTN (28.2+/-12.9 mm Hg before ISDN vs. 22.5+/-13.7 mmHg after P<0.01). The phasic SO motility was also strongly inhibited by both drugs. However, the effect of GTN completely wanes after 3 minutes, whereas ISDN inhibited SO motility for > 5 minutes in all patients. CONCLUSIONS: Both topically administered GTN and ISDN evoked a profound inhibition of SO motility, but the effect of ISDN was longer lasting than that of GTN. However, locally administered GTN did not facilitate selective bile-duct access during routine ERCP.

Administration, Topical↗