Small Balloon Catheter Research Articles

Vaginal Lubrication and Pressure Increase Induced by Pudendal Nerve Stimulation in Cats

Vaginal lubrication and contractions are among the top difficulties affecting sexual intercourse in women after spinal cord injury. This study aimed at determining if pudendal nerve stimulation (PNS) can improve vaginal lubrication and induce increases in vaginal pressure. In anesthetized cats, a small piece of cotton was inserted into the vagina for 10 minutes with or without PNS to measure vaginal wetness by the weight increase of the vaginal cotton. Then, a small balloon catheter was inserted into the vagina to measure the pressure increase induced by PNS. Intensity response of the vagina to PNS (30 Hz, 0.2 ms, 5 seconds) was determined at 1-4 times of intensity threshold (T) for PNS to induce an observable vaginal pressure increase. Frequency response was determined at 2T intensity in a range of PNS frequencies (5-50 Hz). Finally, fatigue in vaginal pressure was determined by applying PNS (30 Hz, 2T) either continuously or intermittently (5 seconds on and 5 seconds off) for 4 minutes. The effectiveness of PNS in increasing vaginal wetness and pressure is evaluated. PNS significantly (P=.0327) increased the measurement of vaginal wetness from 15.8 ± 3.8 mg during control without stimulation to 32.4 ± 4.7 mg after stimulation. Vaginal pressure increased as PNS intensity or frequency increased. PNS (30 Hz, 2T) induced vaginal pressure increase ≥80% of the maximal response. Intermittent PNS induced significantly (P=.0354) smaller fatigue (45.6 ± 3.7%) in vaginal pressure than continuous PNS (69.1 ± 3.0%) during the 4-minute stimulation. This study raises the possibility of developing a novel pudendal neuromodulation device to improve female sexual function after spinal cord injury. This study provides preclinical data supporting the development of a novel pudendal neuromodulation device. The limitation includes the lack of chemical analysis of the vaginal secretion. PNS can improve vaginal lubrication and induce increases in vaginal pressure. Chen J, Zhong Y, Wang J, et al. Vaginal Lubrication and Pressure Increase Induced by Pudendal Nerve Stimulation in Cats. J Sex Med 2022;19:1517-1523.

A Modified Catheterization Procedure to Reduce Bladder Damage when Collecting Urine Samples from Holstein Cows

ABSTRACTThis study proposed a modified procedure, using a small balloon catheter (SB catheter, 45 ml), for reducing bladder damage in cows. Holstein cows and the following catheters were prepared: smaller balloon catheter (XSB catheter; 30 ml), SB catheter and standard balloon catheter (NB catheter; 70 ml, as the commonly used, standard size). In experiment 1, each cow was catheterized. The occurrence of catheter-associated hematuria (greater than 50 RBC/HPF) was lower in the SB catheter group (0.0%, n=7) than in the NB catheter group (71.4%, n=7; P<0.05). In experiment 2, general veterinary parameters, urine pH, body temperature and blood values in cows were not affected before or after insertion of SB catheters (n=6). The incidence of urinary tract infection (UTI) was 3.0% per catheterized day (n=22). In experiment 3, feeding profiles, daily excretion of urinary nitrogen (P<0.05) and rate from nitrogen intake in urine (P<0.01), were higher with use of the SB catheter (n=13) than with the use of the vulva urine cup (n=18), indicating that using the SB catheter can provide accurate nutritional data. From this study, we concluded that when using an SB catheter, the following results occur; reduction in bladder damage without any veterinary risks and accuracy in regard to feeding parameters, suggesting this modified procedure using an SB catheter is a useful means of daily urine collection.

Pudendal Neuromodulation for Sexual Dysfunction

Vaginal lubrication and contractions are among the top difficulties affecting sexual intercourse in women after spinal cord injury.This study aimed at determining if pudendal nerve stimulation (PNS) can improve vaginal lubrication and induce increases in vaginal pressure.In anesthetized cats, a small piece of cotton was inserted into the vagina for 10 minutes with or without PNS to measure vaginal wetness by the weight increase of the vaginal cotton. Then, a small balloon catheter was inserted into the vagina to measure the pressure increase induced by PNS. Intensity response of the vagina to PNS (30 Hz, 0.2 ms, 5 seconds) was determined at 1–4 times of intensity threshold (T) for PNS to induce an observable vaginal pressure increase. Frequency response was determined at 2T intensity in a range of PNS frequencies (5–50 Hz). Finally, fatigue in vaginal pressure was determined by applying PNS (30 Hz, 2T) either continuously or intermittently (5 seconds on and 5 seconds off) for 4 minutes.The effectiveness of PNS in increasing vaginal wetness and pressure is evaluated.PNS significantly (P = .0327) increased the measurement of vaginal wetness from 15.8 ± 3.8 mg during control without stimulation to 32.4 ± 4.7 mg after stimulation. Vaginal pressure increased as PNS intensity or frequency increased. PNS (30 Hz, 2T) induced vaginal pressure increase ≥80% of the maximal response. Intermittent PNS induced significantly (P = .0354) smaller fatigue (45.6 ± 3.7%) in vaginal pressure than continuous PNS (69.1 ± 3.0%) during the 4-minute stimulation.This study raises the possibility of developing a novel pudendal neuromodulation device to improve female sexual function after spinal cord injury.This study provides preclinical data supporting the development of a novel pudendal neuromodulation device. The limitation includes the lack of chemical analysis of the vaginal secretion.PNS can improve vaginal lubrication and induce increases in vaginal pressure.Chen J, Zhong Y, Wang J, et al. Vaginal Lubrication and Pressure Increase Induced by Pudendal Nerve Stimulation in Cats. J Sex Med 2022;19:1517–1523.

Editorial Comment: Uni- or bilateral antegrade cerebral perfusion: that is the question!

Editorial Comment: Uni- or bilateral antegrade cerebral perfusion: that is the question!

Protection against skeletal muscle hypoperfusion by adenosine and nitric oxide: together alone?

regulation of vasomotor tone in the microcirculation is essential to ensure adequate tissue oxygenation, particularly when oxygen demand is high, i.e., in skeletal or cardiac muscle during exercise and/or when supply is compromised, i.e., during hypoxia or in the presence of a flow-limiting stenosis

Interventional treatment of transplant renal artery stenosis

目的 探讨移植肾动脉狭窄(TRAS)的介入治疗.方法 21例TRAS患者从肾移植到出现肾动脉狭窄症状平均6.6个月(3～15个月),记录经皮血管成形术(PTA)前后血压变化和肌酐水平.经对侧股动脉或左肱动脉入路,使用普通球囊导管(5 F,直径4～6 mm,长度20～30 mm)和微球囊导管(2.6 F,直径3 mm,长度36 mm)分别对21例TRAS行PTA术,其中5例放置支架.结果21例TRAS患者共行32次PTA(行1次PTA 13例,2次5例,3次3例),其中22次经对侧股动脉,10次经左肱动脉穿刺插管.PTA治疗前肾动脉狭窄率为79%～97%,PTA后狭窄率降为10%～30%.PTA前收缩压150～210 mm Hg(1mm Hg=0.133 kPa),平均170 mm Hg,舒张压90～145 mm Hg,平均120 mm Hg;PTA后收缩压降为100～190 mm Hg,平均135 mm Hg,舒张压降为80～125 mm Hg,平均85 mm Hg.首次PTA后再狭窄率38%,再次PTA后狭窄率14%.32次PTA共使用普通球囊导管25个,微球囊导管7个.5个支架4个为自膨式支架,1个为球囊扩张式.术后随访3～60个月(平均23个月).21例中最终治愈6例,改善8例,好转5例,无效2例.除1例肱动脉入路发生术后穿刺点血肿外无其他并发症.结论 TRAS的PTA治疗安全有效,配合肱动脉入路和微球囊导管有助于提高手术成功率;合理选用支架能降低再狭窄率。

In-Hospital Complications of Percutaneous Intraaortic Balloon Counterpulsation

Complications related to intraaortic balloon counterpulsation pumping (IABP) remain a problem despite the development of small caliber balloon catheter shafts and introducer sheaths. The authors report their experience in counterpulsation-related complications of 201 consecutive patients who underwent 212 percutaneous counterpulsation balloon insertions from June 1989 to June 1996 by use of balloons with 8-9.5 French shafts. Of these, 82% were men and 36 (18%) were women, with a mean age of 61 +/-12 years. Indications for counterpulsation were acute myocardial infarction (AMI) (67%), severe left ventricular failure without AMI (20%), dilated cardiomyopathy (4%), unstable angina (3%), high-risk supported percutaneous coronary angioplasty (2%), and others (4%). IABP was instituted at the bedside in the intensive care unit in 82 patients (39%) and in the catheterization laboratory in 130 (61%). Median duration of counterpulsation was 48 hours (range 30 minutes to 25 days) with successful weaning from counterpulsation in 70% (148 of 212) of procedures. Overall in-hospital mortality rate was 45% (90 of 201). The overall complication rate was 22/212 (10.4%). Major complications were present in 10/212 procedures (4.7%): 6 patients with limb ischemia (1 death directly attributed to this complication, 1 with associated septicemia and limb amputation, 3 requiring surgical thromboembolectomy, and 1 with persistent limb ischemia treated medically until his death caused by intractable left ventricular failure), 2 with important bleeding (1 fatal despite vascular surgical repair and 1 requiring blood transfusion) and 2 with balloon rupture requiring vascular surgery. Minor complications were present in 12 procedures (5.7%), 6 with limb ischemia, 3 with local bleeding, and 3 with catheter dysfunction. All of these resolved after balloon removal and required no further intervention. When limb ischemia did develop it occurred after a median delay of 24 hours following balloon insertion (range 2 to 98 hours). The only predictor of limb ischemia among baseline clinical and procedure-related variables was an age greater than 60 years. Compared with previous recent studies, the rate of complications observed in this study performed with small balloon catheters was acceptably low. Limb ischemia was the most frequent complication, often occurred early, and required further intervention in half the cases.

Early clinical experience with the implantation of a novel synthetic coronary stent graft

Coating stents with autologous venous grafts has been suggested to prevent problems associated with conventional stenting, but the need for surgical vessel harvest hampered broad application. A novel synthetic coronary stent graft (CSG) overcomes this limitation by a synthetic membrane, fixed between two thin metallic stents. We successfully implanted 21 CSGs in 18 patients for treatment of acute coronary rupture, thrombus-containing lesions, and lesions with plaque rupture or adjacent pseudoaneurysm. Substantial residual angiographic diameter stenoses were seen in seven CSGs (25% ± 10% vs. 8% ± 6%; P < 0.01), which were implanted with relatively small balloon catheters (balloon-to-artery ratio 1.00 ± 0.09 vs. 1.24 ± 0.18; P = 0.01) and required postdilatation. Overall, the largest balloon catheter applied measured 4.0 ± 0.7 mm (balloon-to-artery ratio 1.21 ± 0.20) and the inflation pressure was 16 ± 3 atm. Final intravascular ultrasound imaging demonstrated adequate and symmetrical expansion of the CSG (≥85% ± 15% of the reference lumen). Elective implantation was associated with two small non–Q-wave myocardial infarctions, resulting from unavoidable occlusions of side branches. Thus, implantation of CSG is feasible and safe. Adequate expansion can be achieved by the use of relatively large low-compliant balloon catheters inflated with high pressure. Cathet. Cardiovasc. Intervent. 47:496–503, 1999. © 1999 Wiley-Liss, Inc.

Early clinical experience with the implantation of a novel synthetic coronary stent graft.

Coating stents with autologous venous grafts has been suggested to prevent problems associated with conventional stenting, but the need for surgical vessel harvest hampered broad application. A novel synthetic coronary stent graft (CSG) overcomes this limitation by a synthetic membrane, fixed between two thin metallic stents. We successfully implanted 21 CSGs in 18 patients for treatment of acute coronary rupture, thrombus-containing lesions, and lesions with plaque rupture or adjacent pseudoaneurysm. Substantial residual angiographic diameter stenoses were seen in seven CSGs (25% +/- 10% vs. 8% +/- 6%; P < 0.01), which were implanted with relatively small balloon catheters (balloon-to-artery ratio 1.00 +/- 0.09 vs. 1.24 +/- 0.18; P = 0.01) and required postdilatation. Overall, the largest balloon catheter applied measured 4.0 +/- 0.7 mm (balloon-to-artery ratio 1.21 +/- 0.20) and the inflation pressure was 16 +/- 3 atm. Final intravascular ultrasound imaging demonstrated adequate and symmetrical expansion of the CSG (> or = 85% +/- 15% of the reference lumen). Elective implantation was associated with two small non-Q-wave myocardial infarctions, resulting from unavoidable occlusions of side branches. Thus, implantation of CSG is feasible and safe. Adequate expansion can be achieved by the use of relatively large low-compliant balloon catheters inflated with high pressure.

Effets de la prise aiguë d'alcool sur la fonction des voies aériennes supérieures

Acute alcohol intake may be of potential hazard in anaesthesia emergency procedures because of consciousness alterations. Alcohol ingestion alters indeed the functions of upper airway muscles and increases the risk of obstructive sleep apnea. However, no data are available on the effects of alcohol on the swallowing reflex (SR), which is a major protective mechanism against pulmonary inhalation and on upper airway resistances (UAR) following external inspiratory load application. This study was designed to investigate the effects of acute alcohol intake on SR and UAR in healthy volunteers. After informed consent, 8 male volunteers (29 ± 3 years) were studied in the supine position. The tip of a catheter was placed through the naris at the epipharynx level for injection of 3 series of 2 volumes of distilled water (0.25 and 1 ml respectively). Swallows were identified by a submental electromyogram. SR efficiency was assessed by recording 1) the latency (L) between injection and the first swallow, and 2) the number of swallows (N) elicited by each bolus. The subjects were breathing through a facial mask connected to a pneumotachograph. Supraglottic airway pressures (UAP) were recorded using a small balloon catheter placed at the tip of the epiglottis. UAR were calculated as the ration of UAP (cmH 2O) on air-flow (l · s −1) at the airflow's peak. After a control set of measurements (TC), including SR assessment and UAR at rest (UARo) and during application of an external inspiratory resistive load (12 cmH 2O · l −1 · s −1) (UARr) to sensitize the experiment, the subjects ingested 1 ml · kg −1 of alcohol as 40° vodka. Measurements were repeated and alcohol blood concentrations assessed 25 (T25) and 45 (T45) min after intake. Statistical analysis were performed using the Kruskal Wallis non parametric test. All subjects were drowsy at T25 and T45 with alcohol blood concentrations of respectively 0.96 ± 0.12 and 1.01 ± 0.15 g · l −1 (mean ± SEM). Although all demonstrated consciousness alterations after acute alcohol intake, no changes in the SR, UARo and UARr occurred. However, these data obtained in young and healthy volunteers can be extended neither to patients receiving sedative agents or opioids nor to elderly as UAR are closely related to age, nor to patients with higher alcohol blood concentrations.

Measurement of transmural distribution of phosphorus metabolites in the pig heart by 31P magnetic resonance spectroscopy.

We used the phase modulated rotating frame imaging technique to measure transmural distribution of phosphorus metabolites in 10 anaesthetised ventilated pigs using a double surface coil placed on the surface of the left ventricle. Anaesthesia was maintained in five animals with halothane, barbiturate and nitrous oxide and in five others with intravenous chloralose. 31Phosphorus spectra were acquired, gated to expiration and systole. From phantom experiments the resolution of the experiment was shown to be approximately 2 mm. The anatomical limits of the myocardium were identified by the appearance of 2,3-diphosphoglycerate peaks from red blood cells. The limits of the epicardium were confirmed by obtaining images after placing a phantom containing fluorophosphate on the surface of the heart. The endocardium was identified by inserting a small balloon catheter through the centre of the coil into the left ventricular cavity, filling it with 0.5 ml of fluorophosphate and pulling it gently against the endocardium. No transmural differences in phosphocreatine to ATP ratio were identified in the normal heart. The animals anaesthetised with chloralose showed a significantly higher phosphocreatine to ATP ratio compared to those anaesthetised with halothane and barbiturate. The chloralose animals tended to have a higher blood pressure and a lower heart rate when compared to the other animals. No transmural differences, however, were identified in either group. When regional ischaemia was produced using a snare to occlude the left coronary artery, phosphocreatine fell and the signal from the inorganic phosphate + 2,3-diphosphoglycerate region increased. The inner wall tended to become more acid compared to the outer wall during ischaemia. These experiments show that the phase modulated rotating frame imaging technique can be used to study the effects of changes in workload, ischaemia, or pharmacological intervention on transmural distribution of metabolites in the heart and thus help elucidate factors responsible for subendocardial vulnerability to stress.

Use of short-tapered catheters in combination with a balloon catheter for markedly stenotic renal and brachiocephalic arteries.

Percutaneous transluminal angioplasty (PTA) has become a routine therapeutic technique for steno-occlusive arterial diseases. In the renal and brachiocephalic arteries, stenosis is frequently severe and a dilatation balloon catheter cannot be advanced through the stenosis, although a small catheter or a guide wire can be passed. Under such circumstances a small balloon catheter, as used for coronary artery angioplasty, has been applied with some success, (Korogi et al, 1985). However, there have been some cases in which this was not possible. In marked stenosis of the iliac and femoro-popliteal arteries, advancement of a guide wire is usually initiated with subsequent introduction of a long tapered Teflon catheter, which prepares the pass for a dilatation balloon catheter (Van Andel, 1976; Rosen et al, 1981). To avoid this, Barth (1983) devised a tapered balloon catheter but because of technical difficulties encountered with this method (see discussion) we have designed short-tapered catheters of varying ...

Tachycardia induced reduction in coronary blood flow distal to a stenosis

Clinical and experimental data indicate that some coronary stenoses can rapidly change shape thereby influencing the hemodynamic severity of the stenosis. In 7 closed chest dogs, we examined the effects of distal coronary arteriolar vasomotor tone and myocardial oxygen demands on a coronary stenosis created by partial intraluminal occlusion, using a small balloon catheter. Myocardial blood flow (ml/g per min) was measured with 15-μm radioactive microspheres. Stenotic resistance was calculated as the mean pressure gradient across the stenosis divided by the mean blood flow through the stenosis. The mean pressure gradient was calculated as the ascending aortic pressure minus the left anterior descending coronary artery pressure distal to the stenosis. Coronary arteriolar vasodilation induced by pacing (170 beats/min) increased stenotic resistance (1.64 ± 0.27 to 26.48 ± 13.77 mmHg/ml per min, P < 0.05) and decreased myocardial blood flow (endocardial 0.42 ± 0.04 to 0.17 ± 0.04, P < 0.05, midcardial 0.35 ± 0.03 to 0.13 ± 0.04, P < 0.05; epicardial 0.22 ± 0.05 to 0.15 ± 0.05). Five dogs fibrillated within 10 min of continuous tachycardia and partial arterial occlusion. The change in arteriolar vasomotor tone and decreased aortic pressure induced by pacing altered the severity of the stenosis and resulted in a reduction of blood flow to the myocardium.

Regional wall stiffness during acute myocardial ischaemia in the canine left ventricle.

In eight anaesthetized closed-chest dogs, acute myocardial ischaemia was produced for 30 to 90 s by inflating a small balloon-catheter, which had been advanced transaortically into the periphery of the left anterior descending coronary artery. Left ventricular high-fidelity pressure measurements and simultaneous angiocardiography were carried out at control and during ischaemia. Left ventricular systolic function was assessed by the left ventricular ejection fraction (EF) as well as by regional shortening in a basal (SH M1), middle (SH M2 and apical (SH M3) segment. Diastolic function was evaluated by the stress-strain relationship using a viscoelastic model. Regional wall stiffness (Kn) was determined in the same three segments (basal, middle and apical), which were used for the evaluation of regional systolic function. For the interindividual comparison of the diastolic stiffness parameters normalization of the strain data was performed by calculating a reference wall circumference (I) at a common wall stress of 1000 dynes/cm2. During localized myocardial ischaemia left ventricular end-diastolic pressure remained essentially unchanged (7.2 v. 8.3 mm Hg: NS). Left ventricular EF (47 v. 31% P < 0.001), SH M2 (27 v. 14 % P < 0.005) and SH M3 (22 v. 2% P < 0.02) decreased during ischaemia. Kn in the middle (10.0 v. 14.2; P < 0.02) and the apical (9.8 v. 12.7, P < 0.005) segment increased during ischaemia whereas Kn in the non-ischaemic basal segment remained unchanged (9.6 v. 11.8; NS). During ischaemia I increased in the middle segment (15.7 v. 17.3 cm; P < 0.005). Our data indicate that during acute ischaemia regional myocardial wall stiffness is increased in the ischaemic segment, but is normal in the non-ischaemic segment. Reference midwall circumference at a common wall stress of 1000 dynes/cm2 is enhanced during acute ischaemia (creep) and corresponds with the increased sarcomere length reported in ischaemic myocardium. Thus, it is suggested that the changes in regional myocardial wall stiffness are related to changes in reference midwall circumference with creep.

A percutaneous technique for producing intraspinal mass lesions in experimental animals.

✓ The authors describe a percutaneous technique for producing extra- and intramedullary mass lesions in the dog and monkey. Small balloon catheters introduced through needles into the spinal canal can be positioned under fluoroscopic control to simulate epidural masses or masses within the cord. Selective spinal cord arteriography and silicone perfusion studies demonstrate the effect of such masses on spinal cord blood flow.