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PubMed1994

Myocardial vagal stimulation impairs lower esophageal sphincter function.

BACKGROUND: Coronary artery disease and gastroesophageal reflux disease frequently coexist, but a direct pathophysiologic link has not been established. METHODS: This study examines the effect of myocardial vagal receptor stimulation on lower esophageal sphincter (LES) tone in eight adult mongrel dogs, each acting as its own control. Pharmacologic stimulation was carried out by the application of 1 cm gauze patches soaked in nicotine (200 micrograms/ml) to the epicardium. Epicardial vagal receptors were stimulated mechanically by digital friction. RESULTS: Pharmacologic stimulation produced a rapid fall in LES tone from a mean (SEM) of 12.6 (1.5) to 8.6 (0.9) sphinctometer units (p = 0.007). Mechanical stimulation also produced a rapid fall from 12.0 (1.5) sphinctometer units to 6.8 (0.7) (p = 0.007). Both were associated with a drop in mean arterial blood pressure and heart rate. Sham patches soaked in sterile water produced no effects. CONCLUSIONS: These data suggest a direct vagal reflex linking the myocardium and the LES that may explain the high incidence of gastroesophageal reflux in patients with heart disease.

Animals↗
PubMed2005

Elimination of a long-range cis-regulatory module causes complete loss of limb-specific Shh expression and truncation of the mouse limb.

Mutations in a conserved non-coding region in intron 5 of the Lmbr1 locus, which is 1 Mb away from the sonic hedgehog (Shh) coding sequence, are responsible for mouse and human preaxial polydactyly with mirror-image digit duplications. In the mouse mutants, ectopic Shh expression is observed in the anterior mesenchyme of limb buds. Furthermore, a transgenic reporter gene flanked with this conserved non-coding region shows normal polarized expression in mouse limb buds. This conserved sequence has therefore been proposed to act as a long-range, cis-acting regulator of limb-specific Shh expression. Previous phylogenetic studies have also shown that this sequence is highly conserved among tetrapods, and even in teleost fishes. Paired fins of teleost fishes and tetrapod limbs have evolved from common ancestral appendages, and polarized Shh expression is commonly observed in fins. In this study, we first show that this conserved sequence motif is also physically linked to the Shh coding sequence in a teleost fish, the medaka, by homology search of a newly available genomic sequence database. Next, we show that deletion of this conserved intronic sequence by targeted mutation in the mouse results in a complete loss of Shh expression in the limb bud and degeneration of skeletal elements distal to the stylopod/zygopod junction. This sequence contains a major limb-specific Shh enhancer that is necessary for distal limb development. These results suggest that the conserved intronic sequence evolved in a common ancestor of fishes and tetrapods to control fin and limb development.

Animals↗
PubMed2003

Acellular and glutaraldehyde-preserved tendon allografts for reconstruction of superficial digital flexor tendon in bovines: Part I--Clinical, radiological and angiographical observations.

Sixteen tenorrhaphies were performed at the mid-metatarsal region in eight buffalo calves under lignocaine epidural analgesia. A 2 cm long gap was created in the superficial digital flexor (SDF) tendon and immediately repaired with acellular grafts in animals of group I, 1% glutaraldehyde-preserved tendon allografts in group II. In group III, the defect was repaired with autografts. This group served as control. The contralateral limb in each animal was operated after an interval of 60 days and the animals underwent the same procedure according to the designed groups. Diclofenac sodium and Enrofloxacin was given post-operatively for 5 days. Clinical examination revealed significant increase (P < 0.05) in rectal temperature, heart and respiratory rate for 3-4 postoperative days in all the animals. Mild pain and exudation as well as early restoration of tendon gliding movements and weight-bearing were observed earlier in group I in comparison with group II. Air-tendograms revealed early organization, minimal adhesion formation and lesser thickening of tendon at the reconstructive site in the acellular group whereas in the glutaraldehyde group dense homogenous swelling with adhesions was seen along the flexors. Angiography on day 30 showed that the area of proximal and distal host tendon graft junction appeared hypervascularized, whereas the area occupied by the graft appeared relatively less vascularized. Normal vascularization was observed on day 90 in all the three groups.

Angiography↗
PubMed1997

In vivo study of approximal caries depth on storage phosphor plate images compared with dental x-ray film.

The aim of this in vivo study was to compare approximal caries depth on storage phosphor plate images to conventional film. A Soredex Digora imaging plate was placed in a film bite-wing positioner behind a Kodak Ektaspeed Plus film package without lead foil. The effect of scattered radiation on film without lead foil with a storage phosphor plate at the back was studied in a separate in vitro experiment. Compared with film protected by lead foil, the film showed higher density, but comparable contrast. For the in vivo study, clinical bite-wing exposures were made with the setup described above, with exposure settings for Ektaspeed Plus film. A four-point scale was chosen for approximal caries depth: 0 = no caries; 1 = caries in enamel; 2 = caries reaching dentino-enamel junction; 3 = caries into dentin. The bite-wing film images were shown to a panel of four experts. Sixty surfaces were selected for observer performance, based on identical scorings of the experts consensus classification. Next, six dentists evaluated both film and storage phosphor plate images with the same four point scale. Analysis of variance revealed a significant observer and image modality effect without an interaction effect. In conclusion, caries depth on storage phosphor plate images was underestimated compared with film-based images.

Dental Caries↗
PubMed2000

An electro-myographic study of the distal porcine ureter.

PURPOSE: The accumulation of urine in the renal pelvis causes depolarisation of non-specific muscular pace-maker cells. The wave of depolarisation spreads distally in the ureteric smooth muscle cells via gap junctions. This wave of excitation causes a coordinated peristaltic contraction which transports the urine bolus distally to the bladder. The EMG activity in the distal porcine ureter was studied and analyzed to establish the characteristics of ureteric excitation. MATERIALS AND METHODS: Ten female New Yorkshire pigs (50 to 60 kg.) were studied in two groups under light halothane anesthesia (5% at induction and 1% for maintenance anesthesia). In both groups each pig was studied in two separate sessions at a week's interval. In group I (n = 5), bipolar needle electrodes (o: 0. 09 mm.) were implanted through a lower mid-line abdominal incision in the posterior bladder wall, the trigone and the pelvic ureter at intervals of 3 and 8 cm., respectively, from the ureteric orifice. In group II (n = 5), EMG spike burst activity was studied using a twin bipolar ring-electrode attached to an endoluminal ureteric catheter. EMG complexes were recorded using 0 to 30 Hz filters. The duration of spike burst complexes and their intervals were analyzed using a Nicollet, Pathfinder II(R) machine and a Poly(R) 4.9 digital signal processing program. RESULTS: Two types of spike burst activity could be distinguished between the electrodes: A, the migrating type and B, the non-migrating type. Frequency distribution analysis of spike burst duration revealed two main classes in experimental group II, a short spike burst (96%) which lasted 4.5 +/- 1.8 seconds and a longer one lasting 13.4 +/- 1.5 seconds. The conduction velocity of the migrating spike bursts (n = 177, 42% of total) between the proximal and the distal electrode had an average of 2.3 +/- 1.3 cm./sec. No relationship was found between the duration of the proximal spike burst and the conduction velocity. Data from experimental group I correlated well with data from group II. CONCLUSIONS: The results of our EMG study in the distal ureter reveal an approximately 9 cm. long electrically active zone in >/= 90% of EMG activity recordings. The duration of activity was approximately 5 seconds. Such an excited segment of ureter led to a contraction which occluded the ureter and could prevent retrograde leakage of intraluminal contents.

Action Potentials↗
PubMed2005

Functional outcome of extensor carpi radialis longus transfer for finger flexion in posttraumatic flexor muscle loss.

PURPOSE: The purpose of this study was to assess the functional outcome after extensor carpi radialis longus (ECRL) transfer for restoration of finger flexion in patients with flexor muscle loss after direct trauma. METHODS: We evaluated 8 patients who had ECRL transfer between 1995 and 2003. Flexion gained was assessed by measuring the digit-to-palm distance (DPD). The grip strength was compared with that of the opposite normal limb. The average follow-up period was 41 months. We compared the results obtained with other modalities of restoration of finger flexion, namely a pedicled latissimus dorsi muscle transfer or a free functioning muscle transfer (FFMT) using the series available in the literature. RESULTS: Four patients had a good result with a DPD of 0 cm in all fingers and an average grip strength of 65% of the opposite hand. Two patients had an average result with a DPD of 1.5, 2, 1.7, and 1.5 cm for the index, middle, ring, and small fingers, respectively, and an average grip strength of 58%; 2 patients had a poor result with a DPD of 5.0, 5.5, 5.0, and 3.0 cm for the index, middle, ring, and small fingers, respectively, and with an average grip strength of 21% of the opposite hand. CONCLUSIONS: The ECRL transfer yields good results if the intrinsic muscles of the hand are functioning, the extensor compartment is uninjured, and the lower third of the forearm where the tendon junction is performed is relatively unscarred. In such instances the range of movement and grip strength achieved are better than a latissimus dorsi muscle pedicle graft and are comparable with a FFMT. This is achieved earlier than the time taken for reinnervation of FFMT and without the attendant risks for flap failure. The ECRL transfer for finger flexor restoration is a more simple alternative that should be considered when possible.

Adolescent↗
PubMed2001

Reliability of lateral bending and axial rotation with validity of a new method to determine axial rotation on anteroposterior cervical radiographs.

OBJECTIVE: To investigate the reliability of a new radiographic measurement of axial rotation and lateral bending on anterior-posterior cervical views by using a computer and sonic digitizer. DESIGN: A blind, repeated-measure design was used. Anteroposterior cervicothoracic radiographs were presented to each of 3 examiners in random order. Each film was digitized, and 1 week later the films were randomized for a second run. SETTING: Private, primary-care chiropractic clinic. MAIN OUTCOME MEASURES: The interclass and intraclass correlation coefficients (ICC) for intraexaminer and interexaminer reliability were calculated from measurements on radiographs for determining axial rotations (Ry) and lateral bending (Rz) of C3 to T3. RESULTS: When the new axial rotation method was applied to small rotations of a C3 plastic model, the average error was less than 1 degrees. For the calculations of axial rotation (Ry), the ICC values were in the good to excellent range. For axial rotation, the intraclass correlation coefficients were ICCs > or =0.78, and the interclass correlation coefficients were ICCs > or =0.67. For lateral flexions (Rz) of C3 to T3, all intraclass and interclass correlation coefficients were in the excellent range (ICCs > 0.87). CONCLUSIONS: Methods of calculating axial rotations in the spine have been reported for large angles (5 degrees to 30 degrees ) but not for smaller angles. A new method for determining axial rotations of the cervical segments on AP views, based on the chord across the arc displaced by the spinous-lamina junction, had reliability (ICC values) in the good to excellent range. Compared with measured rotations of a C3 model (-5 degrees to +5 degrees ), the new method had an average error of less than 1 degrees and approximately 11.5%. The reliability for the axial rotation measurements was in the good to excellent range, and the lateral bending measurements were all in the excellent range.

Cervical Vertebrae↗
PubMed1978

Human muscle afferent responses to tendon taps. I. Characteristics of the waveform recorded with transcutaneous electrodes.

Responses of muscle afferent nerve fibres to tendon taps of digital muscles in the human can be recorded with surface electrodes attached to the skin over the nerve at the wrist. Using an effectively monopolar recording method, a considerable improvement in signal amplitude is achieved with simultaneous reduction in mechanical artefacts using differential amplification techniques. The characteristics of the afferent waveform (latency and duration) are discussed in relation to the applied stimulus. The contribution to the afferent response from receptors other than in the muscle have been shown to be minimal. Afferent fibres from primary muscle spindle endings are thought to be the major contributors to the afferent waveforms recorded by this technique.

Adult↗
PubMed2006

[Etiology, diagnosis and management of spontaneous per renal hemorrhage].

OBJECTIVE: To investigate the etiology, diagnosis, and management of spontaneous perirenal hemorrhage (SPH). METHODS: The clinical data of 35 patients, 10 males and 12 females, aged 35.9 (12-77), with the diagnosis of SPH, without history of trauma, anticoagulant use, dialysis, and renal transplantation, were analyzed. RESULTS: The underlying disease of SPH included angiomyolipoma (18 cases), renal cell carcinoma (7 cases), kidney cyst (2 cases), renal artery aneurysm (3 cases), rupture of renal artery aneurysm accompanied with pregnancy (2 cases), renal pheochromocytoma (3 cases 2 of which accompanied with pregnancy), congenital stricture of pelvic ureter junction (1 case), and liver cancer (1 case). The most common underlying diseases were nephrogenic (96%) with angiomyolipoma ranking first (54%) followed by renal cell carcinoma (21%). The underlying diseases were diagnosed correctly in 23 cases (69%). CT helped in diagnosis of 34 cases. Surgery was performed on most of the cases. CONCLUSION: The most common causes of SPH is renal neoplasms more than 50% of which are benign. Renal artery aneurysm and pheochromocytoma tend to rupture during pregnancy. CT is the first method of choice in diagnosis.

Adolescent↗
PubMed2001

The tetrapod limb: a hypothesis on its origin.

A wrist joint and structures typical of the hand, such as digits, however, are absent in [Eustenopteron] (Andrews and Westoll, '68, p 240). Great changes must have been undergone during evolution of the ankle joint; the small number of large bones in the fin must somehow have developed into a large number of small bones, and it is very difficult to draw homologies in this region, or even be certain of what is being compared (Andrews and Westoll, '68, p 268). The tetrapod limb is one of the major morphological adaptations that facilitated the transition from an aquatic to a terrestrial lifestyle in vertebrate evolution. We review the paleontological evidence for the fin-limb transition and conclude that the innovation associated with evolution of the tetrapod limb is the zeugopodial-mesopodial transition, i.e., the evolution of the developmental mechanism that differentiates the distal parts of the limb (the autopodium, i.e., hand or foot) from the proximal parts. Based on a review of tetrapod limb and fish fin development, we propose a genetic hypothesis for the origin of the autopodium. In tetrapods the genes Hoxa-11 and Hoxa-13 have locally exclusive expression domains along the proximal-distal axis of the limb bud. The junction between the distal limit of Hoxa-11 expression and of the proximal limit of Hoxa-13 expression is involved in establishing the border between the zeugopodial and autopodial anlagen. In zebrafish, the expression domains of these genes are overlapping and there is no evidence for an autopodial equivalent in the fin skeleton. We propose that the evolution of the derived expression patterns of Hoxa-11 and Hoxa-13 may be causally involved in the origin of the tetrapod limb.

Adaptation, Physiological↗
PubMed1985

Rates of diffusion of fluorescent molecules via cell-to-cell membrane channels in a developing tissue.

Diffusion coefficients for the intercellular movement of fluorescent tracers have been measured in the epidermis of a larval beetle. Fluorescent tracer was injected into a cell and the spread of tracer from cell to cell in this monolayer was recorded by a TV camera. Fluorescence intensities were digitized from the TV images at successive times after the start of injection at various distances from the source by a microcomputer interfaced with a video analyzer. From the relationship between concentration (measured as light intensity), time and distance, an effective diffusion coefficient (De) is calculated for the tracer in the tissue. In newly ecdysed epidermis, De for carboxyfluorescein (CF) is 2.7 X 10(-7) cm2/s, and De for lissamine rhodamine B (LRB) is 1.2 X 10(-7) cm2/s, whereas in intermolt epidermis the De's for CF and LRB are 3.7 X 10(-7) and 1.2 X 10(-7) cm2/s, respectively. These diffusion coefficients are only an order of magnitude lower than their values in water. The ratio of De for the two tracers at these two stages of development differs from the ratio predicted in cytoplasm alone, with the movement of the slightly larger molecule (LRB) being impeded relative to that of the smaller molecule (CF). This suggests that the properties of the membrane channels amplify differences in the rates of movement of molecules of similar size. This may be important during cell patterning in development. De for CF was also monitored as junctional resistance was increased in the epidermis. During 30 min of exposure to 0.25 mM chlorpromazine, De dropped to 20% of its initial value of 5 X 10(-7) cm2/s, implying that the junctional membrane, rather than cytoplasm, is the major barrier to molecular diffusion among the cells.

Animals↗
PubMed1991

Cytoplasmic dye transfer between metastatic tumor cells and vascular endothelium.

Metastatic colonization of a secondary organ site is initiated by the attachment of blood-borne tumor cells to organ-specific adhesion molecules expressed on the surface of microvascular endothelial cells. Using digital video imaging microscopy and fluorescence activated cell sorting techniques, we show here that highly metastatic cells (B16-F10 murine melanoma and R3230AC-MET rat mammary adenocarcinoma cells) previously labeled with the fluorescent dye BCECF begin to transfer dye to endothelial cell monolayers shortly after adhesion is established. The extent of BCECF transfer to endothelial cell monolayers is dependent upon the number of BCECF-labeled tumor cells seeded onto the endothelial cell monolayer and the time of coculture of the two cell types, as visualized by an increase in the number of BCECF-positive cells among cells stained with an endothelial cell-specific mAb. Dye transfer to BAEC monolayers proceeds with a progressive loss of fluorescence intensity in the BCECF-labeled tumor cell population with time of coculture. The transfer of dye is bidirectional and sensitive to inhibition by 1-heptanol. In contrast, poorly metastatic B16-F0 melanoma cells and non-metastatic R3230AC-LR mammary adenocarcinoma cells do not efficiently couple with vascular endothelial cells. It is inferred from these experiments and from the amounts of connexin43 mRNA expressed by tumor cells that tumor cell/endothelial cell communication is mediated by gap junctional channels and that this interaction may play a critical role in tumor cell extravasation at secondary sites.

Animals↗
PubMed2003

The influence of motor system degradation on the control of handwriting movements: a dynamical systems analysis.

The complex dynamics of the human hand/arm system need to be precisely controlled to produce fine movements such as those found in handwriting. This study employs dynamical systems analysis techniques to further understand how this system is controlled when it is functioning well and when it is compromised through motor function degradation (e.g. from tremor). Seven people with and 16 people without multiple sclerosis (MS) participated in this study. Tremor was assessed using spirography with participants being separated into "tremor" (6 people with and 1 person without MS; 2 male, 5 female; age range 40-68) and control (1 person with and 15 people without MS; 5 male, 11 female, age range 18-59) groups. Participants wrote the pseudo-word "lanordam" six times on a digitizer, in a quiet as well as a noisy, mildly stressful environment. Velocity profiles of the pen tip for the best four trials were concatenated and analyzed to determine their dimensionality (a measure of the number of control variables) and Lyapunov exponents (a measure of predictability). Results indicate that the velocity profiles for people with tremor were lower dimensional and had less predictable dynamics than for controls, with no effect of sound condition. Interpreted in the context of related research, it was speculated that the lower dimensionality reflected the loss of control of variables related to the minimization of movement variability, resulting in less predictable movements.

Adult↗
PubMed2004

Corticospinal excitability during painful self-stimulation in humans: a transcranial magnetic stimulation study.

We investigated changes in the corticospinal pattern of activity in healthy volunteers during sustained noxious and non-noxious mechanical stimulation of the first hand digit, resulting from active (self-stimulation) or passive (externally-induced) pressing against a sharp or blunted tip. The results indicate that, in order to press a finger onto a noxious stimulus with the same force generated to press onto a non-noxious one, the motor cortex adopts a peculiar strategy in terms of recruitment of motor units. This is reflected by an increase of corticospinal excitability (as revealed by motor potentials evoked by transcranial magnetic stimulation of the contralateral primary motor cortex) and EMG activity of agonist muscles, possibly related to an increase of motor unit synchronization.

Adult↗
PubMed1999

Influence of spontaneous sleep positions on nighttime recumbent reflux in patients with gastroesophageal reflux disease.

OBJECTIVE: Body position has been shown to influence postprandial and fasting gastroesophageal reflux (GER) in patients and normal volunteers when they are assigned to lie in a prescribed position. No published studies have evaluated the effect of spontaneous sleeping positions on recumbent reflux in patients with GER. METHODS: Ten patients, three female and seven male (mean age 47.6 yr, range 30-67 yr) with abnormal recumbent esophageal pH <4 on 24-h pH-metry participated. A standardized high fat dinner (6 PM) and a bedtime snack (10 PM) were administered to all patients. GER during spontaneous sleep positions was assessed with a single channel pH probe placed 5 cm above the lower esophageal sphincter (LES) and with a position sensor taped to the sternum. Data were recorded with a portable digital data logger (Microdigitrapper-S, Synectics Medical) and analyzed for recumbent percent time pH <4 and esophageal acid clearance time in each of four sleeping positions. Time elapsed between change in sleeping position and GER episodes was also calculated. RESULTS: Right lateral decubitus was associated with greater percent time pH <4 (p < 0.003) and longer esophageal acid clearance (p < 0.05) compared to the left, supine, and prone. GER episodes were more frequent in the supine position (p < 0.04) and occurred within 1 min after change in sleeping position 28% of the time. CONCLUSIONS: The left lateral decubitus position is preferred in patients with nocturnal GER. Measures to aid patients in sleeping in this position should be developed.

Adult↗
PubMed2002

The angular distribution of vertebral trabeculae in modern humans, chimpanzees and the Kebara 2 Neanderthal.

Bone is known to remodel to optimize its structure according to its mechanical environment. In particular trabecular arcades are thought to align with the orientations of components of principal strain. This paper presents the application of a novel method for quantifying trabecular orientation to test the hypothesis that hominoid posture and locomotion are reflected in trabecular architecture. Lateral radiographs were taken of vertebrae from the entire thoracolumbar spines of eight modern humans, seven Pan troglodytes and one Neanderthal. The radiographs were digitized and a square region of interest located at the centre of each vertebral body selected. Fourier transforms of the regions of interest were performed and the relative magnitude of the transform in each of 16 angular segments calculated. The simple indices of external vertebral body morphology, wedge angle and aspect ratio, were also calculated from the radiographs. All three species exhibit the same pattern, with the majority of trabeculae oriented either axially or dorsoventrally. This suggests that vertebral mechanical loading is similar in chimpanzees and humans, despite their apparent postural and locomotor differences. Significant differences between the magnitudes of the Fourier transform in the 78.75 degrees and 135 degrees orientations of chimpanzee and human vertebrae were observed in all but the upper thoracic spine. As the magnitudes at these orientations in the Neanderthal correspond more closely to that in the human and the orientational features were unrelated to the external vertebral morphology, the difference between the two magnitudes may well prove to be a useful parameter in future phylogenetic analysis. Modern human spines were found to show a greater variation in the proportions of axial and dorsoventral trabeculae with spinal level than chimpanzees, with the greatest differences observed in the upper thoracic spine and thoracolumbar junction, suggesting an association with postural spinal curves.

Animals↗
PubMed2005

Severe thoracic kyphosis in the older patient in the absence of vertebral fracture: association of extreme curve with age.

BACKGROUND AND PURPOSE: Limited data exist on the natural history of thoracic kyphosis in elderly patients. The purpose of this study was to determine the statistical distribution of the thoracic kyphotic angle (TKA) measurement in older patients without vertebral body abnormalities when compared with a young population. METHODS: The TKA was measured by Cobb angle on digital lateral chest radiographs in 90 patients >65 years of age, 60 patients 51-65 years of age, 67 patients 36-50 years of age, and 63 patients 18-35 years of age. Patients with vertebral compression, vertebral body angulation, congenital anomaly, or significant scoliosis were excluded. RESULTS: In patients >65 years of age, average TKA was 41.9 degrees , but the distribution was unexpectedly bimodal, with a low mode at 28.3 degrees and an upper mode at 51.5 degrees (P < .001). Elderly women and men independently demonstrated a bimodal TKA distribution. Two-thirds of elderly women and half of elderly men had a TKA >40 degrees (upper mode). In young patients, average TKA was 26.8 degrees . In middle-aged patients, TKA was intermediate and nonbimodal. CONCLUSION: The TKA distribution in elderly patients (>65 years) without vertebral body abnormality is unexpectedly bimodal (non-normal distribution) with a subpopulation of patients significantly more affected by extreme kyphosis. Extreme thoracic kyphosis therefore occurs independently in a large subset of people, in the absence of vertebral wedge compression. The development of extreme thoracic kyphosis might contribute to excess biomechanical stress in the spine and may identify a population at risk for future vertebral compression fracture in particular at the thoracolumbar junction.

Adult↗
PubMed2005

Retrograde or antegrade double-pigtail stent placement for malignant ureteric obstruction?

AIM: To determine the optimum approach for double-pigtail stent placement in malignant ureteric obstruction. PATIENTS AND METHODS: Retrograde stent placement was attempted in a consecutive series of patients presenting with malignant ureteric obstruction. If retrograde stent placement was unsuccessful, percutaneous nephrostomy was performed immediately followed by elective antegrade stent placement. Identical digital C-arm fluoroscopy for image-guidance and conditions for anaesthesia and analgesia were employed for both retrograde and antegrade procedures. Identical 8 Fr (20-26 cm) double-pigtail hydrophilic coated stents were used for each approach. RESULTS: Retrograde placement was attempted in 50 ureters in 30 patients {19 male, 11 female, average age 61.4 yr (range 29-90 yr)} over a 24-month period. The success rate for retrograde ureteric stent placement was 50% (n = 25/50). Technical failures were due to failure to identify the ureteric orifice (n = 22), failure to cross the stricture (n = 1), failure to pass the stent (n = 1) and failure to pass a 4 Fr catheter (n = 1). Antegrade placement was attempted in 25 ureters with a success rate of 96% (n = 24/25). Failure in the one case was due to inability to cross an upper third stricture secondary to pyeloureteritis cystica. CONCLUSION: It is suggested that retrograde route should be the initial approach if imaging shows no involvement of ureteric orifice (UO), when nephrostomy is technically very difficult or in cases of solitary kidney. The antegrade route is preferred if imaging shows tumour occlusion of the UO or if there is a tight stricture very close to the uretero-vesical junction (UVJ) making purchase within the ureter difficult for crossing the stricture.

Adult↗