Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Ligation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19Linked to original sources

Mesenteric vascular bed responsiveness in bile duct-ligated rats: roles of opioid and nitric oxide systems.

Changes in vascular responsiveness are proposed as the basis for some of the cardiovascular complications in cholestasis. Cholestasis is also associated with accumulation of endogenous opioid peptides and evidence of overproduction of nitric oxide (NO). The possible role of NO or opioid system in cholestasis-induced mesenteric vascular bed responsiveness was investigated. Bile duct-ligated and sham-operated rats were treated for 6 days with either normal saline, naltrexone, an opioid antagonist (20 mg/kg/day) or L-NAME (N(omega)-nitro-L-arginine methyl ester), a nitric oxide synthase inhibitor (3 mg/kg/day). After 7 days, the superior mesenteric artery was cannulated and the mesenteric vascular bed was perfused according to the McGregor method. Baseline perfusion pressure of the mesenteric vascular bed was decreased in bile duct-ligated compared to sham-operated animals. ED(50) of phenylephrine-induced vasoconstriction was increased, but vasoconstriction R(max) was not different in the vascular bed of bile duct-ligated rats and of sham-operated ones. Acetylcholine-induced vasorelaxation was impaired in bile duct-ligated rats (increased ED(50) and decreased vasorelaxation R(max)). Sodium nitroprusside-induced vasorelaxation was not different between bile duct-ligated and sham-operated rats, implying that the smooth muscle components of vasorelaxation were intact. Chronic treatment with L-NAME partially restored both the acetylcholine-induced vasorelaxation and phenylephrine-induced vasoconstriction response in bile duct-ligated rats. Naltrexone treatment also partially restored the acetylcholine-induced vasorelaxation and phenylephrine-induced vasoconstriction in bile duct-ligated rats. There is impaired acetylcholine-induced vasorelaxation in cholestatic rats, probably due to a defect in endothelial function. This study also provided evidence for the involvement of increased opioidergic tone and NO overproduction in cholestasis-induced vascular hyporesponsiveness.

Acetylcholine↗

Peroral transgastric endoscopic ligation of fallopian tubes with long-term survival in a porcine model.

BACKGROUND: We have previously reported the feasibility and safety of the peroral transgastric endoscopic approach for diagnostic peritoneoscopy, liver biopsy, and gastrojejunostomy with long-term survival in a porcine model. This approach eliminates incisions of the abdominal wall, providing a less invasive alternative to diagnostic and therapeutic laparoscopy. We now report successful performance of peroral endoscopic transgastric ligation of Fallopian tubes with long-term survival in a porcine model. METHODS: Six female 50-kg pigs had general anesthesia and irrigation of the stomach with an antibiotic solution. Gastric puncture was performed with needleknife electrocautery followed by balloon dilatation of the tract with 20-mm TTS dilating balloon (Microvasive). A standard upper endoscope that underwent high-level disinfection and gas sterilzation was advanced into the peritoneal cavity through a sterile overtube. Both Fallopian tubes were identified and one was ligated using Olympus Endoloops. The other patent tube served as a control. Tubal patency was evaluated by hysterosalpingogram before and after ligation. After a follow-up period of 2-3 weeks, the pigs were sacrificed for postmortem examination. RESULTS: The Fallopian tubes were easily accessed, identified and ligated in all 6 pigs. In each pig, fluoroscopy confirmed complete obstruction of the ligated tube with preserved patency of the other tube. All pigs survived well and ate heartily without any ill-effects. Postmortem examination did not reveal any peritonitis or intra-abdominal adhesions. The Endoloops were in place with complete obstruction of the ligated tubes and patency of the controls. Histopathologic examination of the tubes showed chronic inflammatory infiltrates without abscesses. CONCLUSIONS: The peroral endoscopic transgastric approach to ligation of the Fallopian tubes with long-term survival is technically feasible and safe in a porcine model. The endoscopic transgastric approach to the peritoneal cavity has potential for a wide array of diagnostic and therapeutic procedures.

Animals↗

Endoscopic ligation of esophageal varices compared with injection sclerotherapy: a prospective randomized trial.

Fifty cirrhotic patients with esophageal varices underwent endoscopic treatment in a prospective randomized trial carried out to compare variceal ligation with injection sclerotherapy, with respect to safety, efficacy, and complications in the initial session. Twenty-five patients each were treated using endoscopic variceal ligation or endoscopic injection sclerotherapy in the initial session and then only endoscopic injection sclerotherapy for all following sessions. Ligations numbered 4.1 at the initial session. The total number of sessions of endoscopic injection sclerotherapy was 4.0 +/- 1.3 in the endoscopic injection sclerotherapy group compared with 3.6 +/- 1.4 in the endoscopic variceal ligation group. The total volume of the sclerosant used by the end of all the sessions was 23.9 +/- 10.3 ml in the endoscopic variceal ligation group and 39.0 +/- 11.5 ml in the endoscopic injection sclerotherapy group (p < 0.0001). In all patients, complete eradication of the varices was achieved, and at 7 to 15 months follow-up no evidence of recurrence was seen. Adverse effects such as pyrexia, chest pain, and pleural effusion after the initial session were significantly lower in the endoscopic variceal ligation group (p < 0.05), and total bilirubin, serum creatinine, lactate dehydrogenase, and urinary beta 2-microglobulin were significantly increased and PaO2 decreased after endoscopic injection sclerotherapy (p < 0.05). This study shows that endoscopic variceal ligation significantly decreased the adverse effects associated with endoscopic injection sclerotherapy in the initial session, and it is recommended as an alternative to sclerotherapy.

Aged↗

Endoscopic hemorrhoidal ligation: preliminary clinical experience.

BACKGROUND: Endoscopic hemorrhoidal ligation may provide an alternative to surgical treatment of internal hemorrhoids. This study assessed the safety and efficacy of endoscopic elastic band ligation for bleeding internal hemorrhoids. METHODS: Endoscopic hemorrhoid ligation was performed in 20 adult patients who had chronic rectal bleeding attributed to internal hemorrhoids. Elastic band ligation was accomplished using a ligating device attached to the end of a video endoscope. Repeat endoscopy was done 3 weeks after the initial procedure. RESULTS: Seventy band ligations were performed during 23 separate sessions. Post-therapy endoscopy showed reduction of hemorrhoidal size by at least one grade in 19 of 20 patients (95%). Bleeding resolved in 19 of 20 patients (95%) in 5.4 months (mean) of follow-up; 18 of 20 (90%) required only one banding session. No major complications (perforation, secondary bleeding, deep ulceration) occurred in this small group. CONCLUSIONS: Preliminary data indicates that endoscopic hemorrhoidal ligation is a safe and effective technique for treating internal hemorrhoids. It holds promise as an important technique for successfully treating and possibly eradicating symptomatic internal hemorrhoids.

Adult↗

Comparison of results and complications of high ligation surgery and microsurgical high inguinal varicocelectomy in the treatment of varicocele.

OBJECTIVES: To prospectively compare sperm parameters, pregnancy and recurrence rates, and complications after randomized high ligation surgery versus microsurgical high inguinal varicocelectomy (MHIV). METHODS: Varicocele was diagnosed by physical examination and color Doppler ultrasound in 468 patients who underwent one of two procedures: high ligation surgery (n = 232) or MHIV (n = 236). The high ligation surgery was left unilateral in 142 and bilateral in 90. The MHIV was left unilateral in 128 and bilateral in 108. The patients were postoperatively evaluated by spermiograms and physical examination. The pregnancy rate was monitored for 2 years. RESULTS: One year after surgery, 34.05% in the high ligation group and 46.61% in the MHIV group had a more than 50% increase in their total motile sperm count (P = 0.000). The increase in sperm count was not statistically different between the two groups (P = 0.1), but the difference in the increase in sperm motility in the MHIV group was statistically significant (P = 0.000). Pregnancy rates at the end of 2 years reached 33.57% in the high ligation group and 42.85% in the MHIV group, not a statistically significant difference (P = 0.0571). The postoperative recurrence as detected by physical examination was markedly different between the two techniques. The recurrence rate was 15.51% in the high ligation group and 2.11% in the MHIV group (P = 0.000). Also, the incidence of postoperative hydrocele was significantly different between the two groups (9.09% in the high ligation group and 0.69% in the MHIV group; P = 0.000). CONCLUSIONS: MHIV has lower recurrence and hydrocele rates, a higher increase in sperm motility, and results in higher pregnancy rates. Therefore, it should be the preferred technique for varicocelectomy.

Adult↗

Endoscopic sclerotherapy versus variceal ligation in the long-term management of patients with cirrhosis after variceal bleeding. A prospective randomized study.

BACKGROUND/AIMS: Long-term endoscopic injection sclerotherapy of oesophageal varices prevents rebleeding in patients with cirrhosis surviving an acute variceal bleeding episode. However, this treatment is associated with a substantial complication rate. Endoscopic band ligation is a newly developed technique in an attempt to provide a safer alternative. The aim of this study was to compare the efficacy and safety of injection sclerotherapy versus variceal ligation in the management of patients with cirrhosis after variceal haemorrhage. METHODS: Seventy-seven patients with cirrhosis who proved to have oesophageal variceal bleeding were studied. After initial control of haemorrhage by sclerotherapy, 40 of the patients were randomly assigned to sclerotherapy and 37 to ligation. Both procedures were performed under midazolam sedation at intervals of 7-14 days until all varices in the distal oesophagus were eradicated or were too small to receive further treatment. RESULTS: The eradication of varices required a lower mean number of sessions with ligation (3.7 +/- 1.9) than with sclerotherapy (5.8 +/- 2.7, p = 0.002). The mean duration of follow-up was similar in both groups (15.6 months +/- 7.3 and 15 +/- 7.4, respectively). The proportion of patients remaining free from recurrent bleeding against time was significantly higher in the ligation group as compared to the sclerotherapy group (chi 2 = 3.86, p = 0.05). Only 13 patients (35%) developed complications in the ligation group as compared to 24 (60%, p = 0.05) in the sclerotherapy group. The mortality rate was similar in both groups (20% and 21%, respectively). CONCLUSIONS: Variceal ligation is better than sclerotherapy in the long-term management of patients with cirrhosis after variceal haemorrhage which was initially controlled with sclerotherapy.

Aged↗

Endothelin-1 in the rat bile duct ligation model of hepatopulmonary syndrome: correlation with pulmonary dysfunction.

BACKGROUND/AIMS: Models of hepatopulmonary syndrome require both hepatic injury and portal hypertension to develop pulmonary microvascular and gas exchange abnormalities. Recently, increased endothelin-1 levels associated with vasodilatation, have been observed in cirrhosis. We investigated endothelin-1 production in common bile duct ligated animals with hepatopulmonary syndrome in comparison to partial portal vein ligated animals that do not develop hepatopulmonary syndrome. METHODS: Organ and plasma endothelin-1 were measured in sham, bile duct ligated and portal vein ligated rats, and Northern analysis and immunohistochemistry were performed in liver. Plasma endothelin-1 levels were correlated with pulmonary endothelial nitric oxide synthase levels and alveolar-arterial oxygen gradients. RESULTS: Hepatic and plasma endothelin-1 increased only after bile duct ligation, and were accompanied by increased hepatic endothelin-1 mRNA and increased endothelin-1 protein in biliary epithelium. Plasma endothelin-1 levels correlated directly with both pulmonary endothelial nitric oxide synthase levels and alveolar-arterial gradients. CONCLUSIONS: Enhanced hepatic production and increased plasma levels of endothelin-1 occur after bile duct ligation, but not after portal vein ligation, and correlate with associated molecular and gas exchange alterations in the lung. Endothelin-1 may contribute to the pathogenesis of hepatopulmonary syndrome.

Animals↗

Differential expression of alpha1-adrenoceptor subtype mRNAs in the dorsal root ganglion after spinal nerve ligation.

In spinal nerve ligated Lewis strain neuropathic rats, pain behaviors and the rate of ectopic discharges of injured sensory neurons were significantly reduced by systemic injection of phentolamine. A pharmacological study indicated that this adrenergic dependency was mediated by alpha(1)-adrenoceptors (alpha(1)-AR). The development of adrenergic sensitivity in injured sensory neurons might have resulted from changes in adrenoceptor expression as a consequence of changed expression of adrenoceptor genes. This possibility was examined by determining the changes in the mRNA expression of 3 subtypes of alpha(1)-ARs, alpha(1a)-, alpha(1b)-, and alpha(1d)-ARs, in the dorsal root ganglia (DRG) after spinal nerve ligation. The L4 and L5 spinal nerves were tightly ligated in Lewis rats. One week later, the L4 and L5 DRG were collected and RNase protection assay (RPA) and in situ hybridization were performed. In the DRG of unoperated rats, a moderate amount of alpha(1a)-AR mRNA was present while the amount of either alpha(1b)-AR or alpha(1d)-AR mRNA was small. After spinal nerve ligation, there was a significant increase in the amount of alpha(1b)-AR mRNA in the nerve ligated DRG as measured by RPA. The amount of alpha(1a)-AR mRNA was decreased to 20% of the normal level while that of alpha(1d)-AR mRNA did not change. The in situ hybridization study showed that the number of alpha(1b)-AR mRNA positive neurons increased in spinal nerve ligated DRG, confirming the results of RPA study. These data suggest that the up-regulated expression of alpha(1b)-AR mRNA in axotomized DRG neurons may play an important role in the development of adrenergic sensitivity in injured sensory neurons and thus contribute to the sympathetically maintained pain in spinal nerve ligated neuropathic Lewis rats.

Animals↗

Inhibition of lung metastasis of osteosarcoma cell line POS-1 transplanted into mice by thigh ligation.

Using a model with external ligation of the thigh, the effect of ischemia-reperfusion injury on tumor growth and the activity of lung metastasis was investigated in mice inoculated a spontaneous murine osteosarcoma cell line (POS-1) in vivo. POS-1 cell suspension was inoculated into the right hind footpad of 70 mice. Four weeks after inoculation, the ipsilateral thigh was ligated for 3 h in 15 mice and the contralateral thigh in 15 mice. Another ten mice were inoculated with POS-1 without ligating the thigh. The number of metastatic foci on the lung surface 6 weeks after inoculation was 2.29+/-0.98 (mean+/-SE) foci/lungs in mice with ipsilateral ligation and 6.25+/-2.41 in mice with contralateral ligation, which were significantly lower than control (13.40+/-1.42 in mice no ligation) (P<0.01). The number of metastatic foci on the lung surface in mice with intraperitoneal injection of superoxide dismutase (SOD) and catalase was 3.25+/-0.65 (mean+/-SE) foci/lungs in mice with ligation which was significantly greater than that in mice without SOD and catalase injection 1.29+/-0.97 (P=0.04). Cell viability was 9.12+/-4.07% with 100 microM H(2)O(2) in 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. It revealed that at concentrations of 100 microM H(2)O(2) or higher was cytotoxic to POS-1. In cell invasion assay, the number of invading cells with 10 microM H(2)O(2) was 2.80+/-0.53 cells/field, which was significantly lower than control (5.93+/-0.18) (mean+/-SE), indicating that low-dose H(2)O(2) suppressed invasion of POS-1. These results suggested that reperfusion injury had selective cytotoxicity to POS-1 through producing reactive oxygen species. Activated oxygen was considered to inhibit the regional growth and the ability of lung metastasis of POS-1 cells.

Animals↗

The effect of lumbar sympathectomy on increased tactile sensitivity in spinal nerve ligated rats.

The aim of this study was to investigate the reason for the contradictory results following surgical sympathectomy on increased tactile sensitivity in spinal nerve ligated rats. For this purpose, firstly the results of L5 spinal nerve ligation alone and both L5 and L6 (L5/6) spinal nerve ligation were compared in Sprague-Dawley rats. Secondly, the difference in tactile sensitivity between the plantar surface (the middle glabrous area on the foot pads of the hind paw) and on the toe (the proximal half of the third and fourth toe of the hind paw) after the spinal nerve injury was studied. Third, we divided the L5 spinal nerve ligated rats into two groups, (i.e. low and high threshold groups) based on the degree of tactile sensitivity and investigated the effect of surgical lumbar sympathectomy (L2-L5) on tactile sensitivity in both the plantar and toe areas. The results show that the tactile sensitivities of L5 spinal nerve ligated rats and L5/6 spinal nerve ligated rats were not different. However, tactile sensitivities of the plantar surface were less than those of toe area suggesting that the response from toe is a better indicator of neuropathic pain. Surgical sympathectomy reduced the response from only the toe area and only in the low threshold group. These results suggest that the reason for the contradictory results of surgical sympathectomy in spinal nerve ligation models is, at least in part, the difference in the degree of mechanical allodynia in each study.

Animals↗

Spinal nerve ligation-induced neuropathy in the rat: sensory disorders and correlation between histology of the peripheral nerves.

We studied the effect of unilateral ligation of two spinal nerves on behavioral pain responses evoked by various types of cutaneous stimuli in the adult rat. Furthermore, we determined the effect of spinal nerve ligation on morphology of the peripheral nerves. The most consistent behavioral finding (83%) was a marked decrease in monofilament-induced hindlimb withdrawal thresholds (mechanical allodynia) ipsilateral to the spinal nerve ligation. This mechanical allodynia was observed as early as during the 1st post-operative day and it persisted up to 2 months (the maximum length of the observation period). In contrast, hyperalgesia to noxious mechanical stimulation (Randal-Sellitto test) was not observed in allodynic rats until the 3rd post-operative day. In a minority of rats (13%), spinal nerve ligation-induced mechanical hyperalgesia without a concomitant mechanical allodynia. There was no corresponding heat hyperalgesia in the injured hindlimb (hot water immersion-, radiant heat- or hot-plate-induced hindlimb withdrawal tests). In contrast, hypoalgesia to heat was observed on the 1st postoperative day, but not later. Neuropathological analysis of the peripheral nerves revealed a dramatic decrease in the number of myelinated nerve fibers distal to the spinal nerve ligation site. The results support the previous evidence indicating that ligation of spinal nerves induces a marked allodynia to mechanical stimulation. However, this mechanical allodynia may differentially dissociate from mechanical and thermal hyperalgesia at various post-operative time points. The marked mechanical allodynia together with a dramatic decrease in the number of myelinated nerve fibers is paradoxical, since the activation of myelinated nerve fibers by monofilaments produced abnormally strong behavioral responses. This paradox may be explained by spinal nerve ligation-induced amplification or disinhibition of tactile signals at central levels.

Animals↗

Long-term changes in sciatic-evoked A-fiber dorsal horn field potentials accompany loose ligation of the sciatic nerve in rats.

The goal of the present study was to examine whether loose ligation of the sciatic nerve was associated with long-term changes in neuronal excitability in the spinal dorsal horn in urethane-anesthetized rats. The sciatic nerve was stimulated with 0. 1 ms long pulses at 1 stimulus/5 min, and the evoked dorsal horn field potentials remained stable in the absence of tetanic stimulation. In one set of control and ligated animals, high-frequency tetanic stimulation was applied to the nerve at 50 Hz (one 400 ms train of twenty 0.1 ms pulses), and the field potentials were recorded again (1 stimulus/5 min) for up to 4 h post-tetanus. In control animals, this protocol produced significant increases in field potential amplitudes at 15, 30 and 60 min post-tetanus. Interestingly, after this time the evoked field potentials began to decrease, and attained less than 50% of their pre-tetanic values at 240 min post-tetanus. In contrast, in ligated rats the pattern of post-tetanic potentiation was significantly different as the increases in amplitude persisted, and at 240 min post-tetanus the field potentials were almost twice their baseline values. In another set of control and ligated animals, low-frequency tetanic stimulation was applied at 5 Hz (one 400 ms train of two 0.1 ms pulses). Again a differential pattern of post-tetanic responses between control and ligated rats was seen. In control animals, a significant decrease in amplitude was evident within 30 min, and the depression became progressively more pronounced as the field potentials attained about a quarter of their baseline values at 180 min, and remained at these low levels at 240 min post-tetanus. On the other hand, in ligated animals, the depression was not significant, and at 240 min post-tetanus the field potentials were still at about 80% of their baseline values. These data demonstrate that long-term changes in spinal dorsal horn neuronal excitability accompany sciatic ligation to perhaps contribute to the development of neuropathic pain. These changes may result from a lessening of normally strong inhibitory processes in the spinal dorsal horn to generate conditions which favor post-tetanic potentiation over depression of dorsal horn neuronal responses.

Action Potentials↗

Femoral vein ligation increases bone mass in the hindlimb suspended rat.

Bone remodeling in response to changing mechanical demands is well recognized. It has been hypothesized that alterations in interstitial fluid flow (IFF), due to intraosseous pressure changes, influence bone remodeling. The goal of this study was to investigate the role of IFF in bone in the absence of mechanical strain using an in vivo model, the hindlimb suspended rat. Bone remodeling was assessed by direct measurements of weight, dimensions, bone mineral content (BMC) and bone mineral density (BMD) by dual-energy X-ray absorptiometry (DEXA), and trabecular density using peripheral computed tomography (pQCT). Ligation of one femoral vein was performed as a means to alter the IFF within the ipsilateral femur; the contralateral limb was sham-operated as control. Animals were suspended for a period of 19 days. Intramedullary pressure in the venous-ligated femurs increased relative to the sham-operated control femurs (27.8 mmHg vs. 16.4 mmHg, p < 0.05), suggesting venous ligation increased IFF proportional to the pressure drop across the bone. Bone mineral content (BMC), when normalized to body weight, increased significantly in the venous-ligated femurs relative to control limbs (115.9 +/- 15.6% vs. 103.8 +/- 13.2%, p < 0.001); similarly, gains in length (106.2 +/- 2.4% vs. 104.5 +/- 2.1%, p < 0.05) and distal width (110.8 +/- 10.3% vs. 106.2 +/- 8.2%, p < 0.05) for the femurs with venous ligation were significantly greater relative to sham control. Furthermore, trabecular density was significantly higher in the femurs with venous ligation (351 +/- 12 g/cm3 vs. 329 +/- 11 g/cm3, p < 0.05). Daily administration of the cyclooxygenase inhibitor, indomethacin, via drinking water, suppressed the length increases observed for the venous ligated femur, suggesting a role for prostaglandins in IFF-mediated remodeling. These results suggest that IFF can directly influence bone adaptation independent of mechanical loading, and supports the hypothesis that fluid flow modulates bone remodeling.

Animals↗

GABA mechanisms and antinociception in mice with ligated sciatic nerve.

In the present study, the effects of GABA (gamma-aminobutyric acid) receptor agonists and antagonists on hyperalgesia induced by sciatic nerve ligation was investigated in mice. The response to morphine or GABA receptor agonists was examined 14 days after unilateral nerve ligation by hot-plate test. Intraperitoneal injection of different doses of morphine (3, 6 and 9 mg/kg), muscimol (0.5, 1 and 2 mg/kg) or baclofen (1, 2.5 and 5 mg/kg) induced a dose-related antinociception in both intact and ligated mice. The response of morphine but not that of muscimol or baclofen, in nerve-ligated mice was significantly less than that induced in the intact animals. The responses induced by muscimol or baclofen in nerve-ligated animals, were reduced by bicuculline or CGP35348 [P-(3-aminopropyl)-P-diethoxymethyl-phosphinic acid], respectively. However, morphine in combination with muscimol (2 mg/kg) tends to induce higher response; the combination of the GABA receptor agonists with morphine did not show potentiation, but additive effect. The opioid receptor antagonist naloxone reduced the response induced by muscimol in nerve-ligated animals. It was concluded that although ligation of the sciatic nerve clearly reduced the analgesic effect of morphine and not that of the GABA agonists, the results nevertheless indicated that morphine and the GABA(A) agonist shared the same mechanism of action.

Animals↗

Impaired renal function in obstructive jaundice: enhanced glomerular thromboxane synthesis and effects of thromboxane receptor blockade in bile duct-ligated rats.

1. Patients with obstructive jaundice are especially susceptible to acute renal failure. We have previously observed that in rats with bile duct ligation impaired renal function is associated with increased urinary thromboxane excretion. 2. In the present study we therefore investigated, in rats with bile duct ligation, renal function, urinary thromboxane excretion and thromboxane B2 synthesis by isolated glomeruli as well as the effects of the thromboxane A2/prostaglandin H2 receptor antagonist Daltroban on renal function in rats with bile duct ligation as compared with sham-operated rats. 3. On the fourth day after bile duct ligation (n = 7 rats) endogenous creatinine clearance as an estimate of glomerular filtration rate was significantly reduced to 0.74 +/- 0.05 (SEM) as compared with 1.06 +/- 0.09 ml min-1 g-1 kidney weight in sham-operated rats (n = 7, P < 0.01). In rats with bile duct ligation, urine volume was slightly increased, whereas urinary sodium (Na+) (P < 0.001) and potassium (K+) (P < 0.01) excretion as well as urine osmolarity (P < 0.05) were significantly reduced and lower than in sham-operated rats. 4. Urinary thromboxane excretion was significantly higher in rats with bile duct ligation than in sham-operated rats: 116.6 +/- 22.3 versus 56.8 +/- 10.2 pmol 24 h-1 100 g-1 body weight (P < 0.05). Thromboxane B2 synthesis in glomeruli isolated from rats with bile duct ligation was also significantly higher than in sham-operated rats: 12.6 +/- 2.0 versus 6.4 +/- 0.9 pmol h-1 mg-1 protein (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗

Effects of ligation type and method on the resistance to sliding of novel orthodontic brackets with second-order angulation in the dry and wet states.

Rectangular stainless steel (SS) archwires were coupled with four SS bracket designs: Mini Diamond Twin, which was a conventional twin bracket; VersaT, which had bumps along the slot floor and rounded slot walls; Shoulder, which had bosses outside the tie-wings to lift the ligation off the archwire; and Synergy, which had bosses between the outer and inner tie-wings, bumps along the slot floor, and rounded slot walls. For all designs, the values of resistance to sliding (RS) were measured at five normal forces and 32 second-order angulations in the dry and wet (saliva) states. RS values at these same angles and states were also measured for the following: Mini Diamond Twin brackets ligated with rings and SS ligature wires; VersaT brackets ligated with rings; Shoulder brackets ligated with rings in a figure-8 and a figure-O around the tie-wings; and Synergy brackets ligated with rings around the outer tie-wings and around the inner tie-wings. In both states, the coefficients of friction were similar for the Mini Diamond Twin, VersaT, and Synergy brackets; the values for the Shoulder brackets were slightly greater than for the other three designs. In the passive configuration, the features of the Shoulder and Synergy brackets reduced RS when the rings were not in contact with the archwires. In the active configuration, the binding behavioral patterns of the brackets were not influenced by ligation methods. Thus, these different ligation types and methods only affected the classical frictional component of RS in the passive configuration.

Elastomers↗

Salvage of poorly developed arteriovenous fistulae with percutaneous ligation of accessory veins.

Many arteriovenous (AV) fistulae fail to achieve an adequate blood flow or size for successful cannulation because of accessory veins. We describe a simple technique to ligate accessory veins that does not require a surgical incision. In this retrospective study, 17 end-stage renal disease patients underwent ligation of accessory veins of poorly developed AV fistulae. There were 14 men and 3 women, and their average age was 50 +/- 13 years. There were 14 radiocephalic and 3 brachiocephalic fistulae. After identifying accessory veins with a fistulogram, two nonabsorbable 2-0 polypropylene (Prolene) sutures were placed percutaneously around each accessory vein in proximity to the AV fistula. Successful ligation was confirmed with a repeat fistulogram. This procedure was undertaken after 4 +/- 3 months following surgical placement. Successful maturation was defined as adequate blood flow to support effective hemodialysis and adequate caliber to allow for repeated cannulation with a 15G or 16G needle. Of 17 AV fistulae, 15 (88%) successfully matured 1.7 +/- 1 month (range, 0.3 to 6 months) after the procedure. The average number of accessory veins ligated was 1.7 +/- 0.8 (range, 1 to 3). All AV fistulae that matured after ligation of accessory veins were functioning at 44.5 +/- 12 weeks after first use. A technique for salvaging nonmaturing AV fistulae not requiring surgical cutdown for ligation of accessory veins is described. AV fistulae mature quickly after ligation of accessory veins. This is a rapid and safe procedure that can increase the prevalence of AV fistulae.

Arteriovenous Fistula↗

Endoscopic ligation compared with sclerotherapy for bleeding esophageal varices in children with extrahepatic portal venous obstruction.

Endoscopic sclerotherapy is an effective treatment for bleeding esophageal varices, but it is associated with significant complications. Endoscopic ligation, a new form of endoscopic treatment for bleeding varices, has been shown to be superior to sclerotherapy in adult patients with cirrhosis. To determine the efficacy and safety of endoscopic sclerotherapy and ligation, the 2 methods were compared in a randomized control trial in 49 children with extrahepatic portal venous obstruction who had proven bleeding from esophageal varices. Twenty-four patients were treated with sclerotherapy and 25 with band ligation. No significant differences were found between the sclerotherapy and ligation groups in arresting active index bleeding (100% each) and achieving variceal eradication (91.7% vs. 96%, P =.61). Band ligation eradicated varices in fewer endoscopic sessions than did sclerotherapy (3.9 +/- 1.1 vs. 6.1 +/- 1.7, respectively, P <.0001). The rebleeding rate was significantly higher in the sclerotherapy group (25% vs. 4%, P =.049), as was the rate of major complications (25% vs. 4%, P =.049). After eradication, esophageal variceal recurrence was not significantly different in patients treated by ligation than by sclerotherapy (17.4% vs. 10%, P =.67). In conclusion, variceal band ligation in children is a safe and effective technique that achieves variceal eradication more quickly, with a lower rebleeding rate and fewer complications compared with sclerotherapy.

Acute Disease↗