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At least 19 recordsLinked to original sources

PubMed2003

Echocardiographic comparison of the standard end-hole cannula, the soft-flow cannula, and the dispersion cannula during perfusion into the aortic arch.

BACKGROUND: Dislodgement of aortic arch atheroma caused by a perfusion "jet" from the aortic cannula may be a major cause of atheroemboli during coronary artery surgery when using cardiopulmonary bypass (CPB). Two very different cannulas, the Soft-Flow aortic cannula and the Dispersion cannula, which have been designed to reduce exit velocity (cm/s) during perfusion, are compared with a standard steel tip cannula and to each other. METHODS: To demonstrate any significant differences transesophageal echocardiography (TEE) was used to measure exit velocity of each cannula at a distance of 1, 2, and 3 cm from the tip and compare flow morphology within the aortic arch. Nine patients in whom the cannula tip could be identified and colored Doppler imaging could demonstrate representative morphology were randomly assigned into one of three groups of 3 patients each: group I, a standard steel-tip end-hole cannula (7.3 mm); group II, the Soft-Flow cannula (8.0 mm); and group III, the Dispersion cannula (8.0 mm). RESULTS: The standard steel tip cannula demonstrated a long narrow perfusion jet. The Soft-Flow cannula morphology was made up of multiple smaller exiting jets. The Dispersion cannula demonstrated a broad wedge-shaped perfusion pattern. Perfusion hemodynamics (cardiopulmonary bypass hematocrit in d/L, cardiopulmonary bypass blood flow in L/m, mean arterial pressure during cardiopulmonary bypass mm Hg, and perfusion line pressure in mm Hg) were not significantly different between each group. The mean velocities between group I (318 +/- 63 cm/s at 1 cm, 296 +/- 60 cm/s at 2 cm, 271 +/- 85 cm/s at 3 cm) and group II (351 +/- 31 cm/s at 1 cm, 240 +/- 103 cm/s at 2 cm, 171 +/- 120 cm/s at 3 cm) were not statistically different. Group III (the Dispersion cannula) demonstrated significantly reduced velocities (174 +/- 22 cm/s at 1 cm, 138 +/- 23 cm/s at 2 cm, 90 +/- 36 cm/s at 3 cm) when compared with the other two groups (p < 0.05, analysis of variance). CONCLUSIONS: The Dispersion cannula is significantly different with a lower perfusion velocity and the elimination of the exiting jet or jets. This cannula warrants further clinical study as it may reduce atheroemboli during cardiopulmonary bypass.

Adult↗

PubMed2004

Digestibility of carbohydrates in growing pigs: a comparison between the T-cannula and the steered ileo-caecal valve cannula.

We compared the determination of ileal and total tract digestibility of carbohydrates in five experimental diets using a double 5 x 5 Latin square design involving a total of 10 cannulated pigs; half of the pigs were equipped with a simple T-cannula and the other half with steered ileo-caecal valve (SICV)-cannula. The diets consisted of nitrogen-free mixture and soya bean meal, sunflower meal, peas or rape seed cake diluted to about 180 g/kg DM protein with the nitrogen-free mixture. There was no significant difference in the digestibility values using the two types of cannulas with regard to organic matter, sugars (sum of glucose, fructose and sucrose), alpha-galactosides (sum of raffinose, stachyose and verbascose), starch, cellulose, total non-cellulosic polysaccharides (NCP) and insoluble NCP constituents. The digestibility values for the NCP residues arabinose and galactose, however, were estimated higher but with a lower variability with the SICV-cannula compared with the T-cannula. The type of cannula did no influence the estimation of the total tract digestibility for any of the major dietary constituents, but the total tract digestibility was slightly more variable when the pigs were equipped with the SICV-cannula compared with the T-cannula. There was no difference in the ileal digestibility of sugars, alpha-galactosides, cellulose and the NCP arabinose and uronic acids residues among the experimental diets, while the ileal digestibility of starch and the remaining NCP sugar residues varied between diets. The total tract digestibility was complete for sugars, alpha-galactosides and starch, whereas the digestibility of the cell wall constituents varied in accordance with the polymeric composition of the cell walls. It was concluded that ileal digesta samples from SICV-cannula are more homogenous than those from the T-cannula. In cases where the precision of each determination is crucial, the SICV-cannula should be the option.

Animal Feed↗

PubMed2001

Comparison of cervical vacuum cup cannula with metal cannula for hysterosalpingography.

OBJECTIVE: The aim of this study was to compare the use of a cervical vacuum cap cannula with the traditional metal cannula. DESIGN: A prospective, randomised, single-blinded comparative study. SAMPLE: Fifty consecutive infertile women undergoing hysterosalpingography for evaluation of infertility METHODS: Hysterosalpingography was performed either with the traditional metal cannula (n = 25) or a cervical vacuum cap cannula (n = 25). MAIN OUTCOME MEASURES: Length of procedure, fluoroscopic time, amount of contrast medium, pain to the patient while applying the cannula and injecting the contrast medium, level of difficulty to the performer, the need to reapply the cannula, complications, and results of the hysterosalpingography. RESULTS: Using the cervical vacuum cap cannula, compared with the metal cannula, the duration of the procedure was significantly shorter (5.3 vs 9.3 minutes; P < 0.001), less fluoroscopic time was needed (0.9 vs 1.8 minutes; P < 0.001), a smaller amount of contrast medium was used (4.6 vs 15.7 mL; P < 0.001), the procedure caused less pain to the patient (3.2 vs 6.8, respectively; on a scale of 1-10; P < 0.001), and was easier for the physician to perform (1.4 vs 3.4; on a scale of 1-10; P < 0.001). No significant differences were encountered between the two groups in the need to reapply the cannula, in the rate of complications or in the results of the hysterosalpingography. CONCLUSIONS: The cervical cap cannula appears to be superior to the traditional metal cannula for performing hysterosalpingography.

Adult↗

PubMed2006

Surgical treatment of axillary hyperhidrosis: a study comparing liposuction cannulas with a suction-curettage cannula.

BACKGROUND: Suction-curettage is a minimally invasive surgical approach for the treatment of focal axillary hyperhidrosis. Studies comparing the efficacy of different surgical cannulas are missing. Therefore, we gravimetrically compared a specially designed cannula versus 2 standard liposuction cannulas. METHODS: Axillary suction-curettage was performed in 42 patients (n = 42). Fourteen patients (n = 14) were operated with a 1-hole liposuction cannula, 14 patients (n = 14) with a larger 3-hole liposuction cannula, and 14 (n = 14) with a sharp suction-curettage cannula. Sweat rates in mg/min were measured by gravimetry before and 6 months after surgery. RESULTS: Sweat rate in the 1-hole liposuction cannula group was significantly reduced from 57.65 +/- 5.85 mg/min to 32.58 +/- 4.64 mg/min (P < 0.001), corresponding to a reduction of 44.15%. Patients operated with the larger 3-hole liposuction cannula showed a significant reduction of sweat rate from 63.95 +/- 8.25 mg/min to 33.14 +/- 6.25 mg/min (P < 0.001), corresponding to a reduction of 49.19%. The largest reduction of sweat rates (63.07%) was achieved with the suction-curettage cannula (61.85 +/- 9.03 mg/min to 21.27 +/- 4.42 mg/min (P < 0.001). No severe side effects were observed. CONCLUSION: Due to the higher efficacy we recommend performing suction-curettage with a sharp suction-curettage cannula.

Adult↗

PubMed2002

Is there any impact of the shape of aortic end-hole cannula on stroke occurrence? clinical evaluation of straight and bent-tip aortic cannulae.

OBJECTIVE: To compare the impact of straight and bent-tip aortic cannulae on stroke occurrence, location, and severity. METHODS: Prospective data were collected on 8,129 patients (coronary artery bypass grafting (CABG) and/or valvular surgery). 'Bent-tip' aortic cannulae were used in 15.6% of cases and 'straight' end-hole cannulae in 84.4% of cases. RESULTS: There were a total of 137 strokes: right anterior 52, left anterior 39, bilateral 23, posterior 18, and location not established 5. With the use of bent-tip cannulae, the incidence of strokes was 0.9% versus 1.8% with straight cannulae (chi2, p = 0.026). Bilateral and posterior strokes occurred more often with the use of straight cannulae (chi2, p = 0.015). Straight cannulae also related to the severity of strokes (chi2, p = 0.003). CONCLUSIONS: There is an influence of the type of cannula on the occurrence, location, and severity of strokes. Straight cannulae cause significantly more often and more severe bilateral and posterior strokes than bent-tip cannulae.

Aged↗

PubMed1987

125I-fibrinogen uptake on peripheral venous cannulas: a comparison between different cannula materials and coatings.

Using a similar technique as 125I-Fibrinogen uptake test for detection of deep venous thrombi, the radioactivity over cannulas inserted into veins on the dorsal aspect of the hands was measured 1, 2, 4 and 24 h after insertion. In three groups of 10 postoperative patients it was by random allocation inserted on one side a siliconized tetrafluorethylene cannula and on the other side one of either: a nonsiliconized tetrafluorethylene cannula and on the other side one of either: a nonsiliconized tetrafluorethylene, a heparinized tetrafluorethylene or a fluorethylenpropylene cannula. The same volume and type of infusion was given in both cannulas. No difference in protein deposition was seen between siliconized and nonsiliconized tetrafluorethylene. A tendency of lower protein deposition, especially at 24 h on heparinized tetrafluorethylene was found. The fluorethylenpropylene cannulas had both over cannula and adjacent vein higher protein deposition at all measurements compared to the siliconized tetrafluorethylene cannula (p less than 0.01). The results implicate that fluorethylenprophylene could induce a higher incidence of thrombophlebitis than tetrafluorethylene cannulas.

Adsorption↗

PubMed1996

The Radial Expanding Cannula and the Conventional Cannula with Sleeve for Operative Laparoscopy

A randomized, case control, prospective trial was performed to determine whether radial expanding cannulas offer advantages over conventional disposable cannulas. Laparoscopy was performed in 20 women using one or the other of these instruments. Pain was evaluated immediately postoperatively, and at 24 and 96 hours with a visual analog scale. No difference between techniques was noted at the immediate postoperative analysis. Pain scores were significantly reduced with the radial expanding cannula at 24 hours (p <0.0005) and 96 hours (p <0.04). Cannula slippage was significantly reduced with the radial expanding cannula compared with the conventional disposable cannula (p <0.02). Three cases of cannula-related bleeding occurred with conventional device, and one with the radial expanding device. The radial expanding cannula results in less long-term pain and less slippage than conventional disposable cannulas.

Journal Article↗

PubMed1981

Rumen and abomasal cannulation of sheep with specially designed cannulas and a cannula insertion instrument.

Rumen and abomasal cannulas for sheep and an instrument that facilitates rapid insertion of the cannulas were developed. The cannulas were made from epoxy-filled polyurethane and were supported by outer support rings held in place by nuts screwed onto the threaded tops of the cannula barrels. The insertion device was used to pull the cannula through a separately made incision in the abdominal wall and to stretch the skin and other tissues over a cone and onto the barrel of the cannula, thus ensuring a tight fit and the formation of a ring of scar tissue that virtually eliminated digesta leakage. Expansion plugs, used to seal the cannulas, were designed to eliminate a twisting force that could be transferred to the cannula when the plugs were secured or released. The plugs were also designed to protrude minimally from the side of the animal. More than 75 sheep were cannulated, and the preparations proved to be relatively maintenance free and resistant to mechanical disturbance by the animal. The cannulas had a long functional life and permitted convenient sampling of digesta and introduction of liquid and solid materials, including digestion bags.

Abomasum↗

PubMed2003

Randomized comparison of the effect of manipulation on incisional parameters associated with a pyramidal laparoscopic trocar-cannula system and the EndoTIP cannula.

We conducted a randomized, controlled trial to evaluate the effect of laparoscopic access cannula manipulation on fascial and incisional characteristics in a white swine model, comparing a pyramidal trocar-cannula system (PTC) and a trocarless threaded cannula (TTC, EndoTIP). We made 6 insertions in 10 animals. Cannulas randomized to the movement group were manipulated in standard fashion in skin and subcutaneous tissues. After dissection, muscle damage scores, wound areas, and maximum wound lengths were determined. Mean muscle damage scores without and with manipulation for the TTC were 0.7 and 1.00, respectively, and for the PTC 1.9 and 2.0. Differences between devices were significant (p = 0.0001) but there were no differences within devices (manipulation vs no manipulation). Mean wound length for the TTC without manipulation (0.699 cm) was less than that after manipulation (1.101 cm, p = 0.0002). The mean nonmanipulated PTC wound length (0.968 cm) was more than that of corresponding TTC wounds (0.699 cm, p = 0.0082) but this difference was lost after manipulation (TTC 1.101, PTC 0.930). Mean wound area for the nonmanipulated TTC was less than that for corresponding PTC wounds (16.99 vs 30.85 mm(2), p = 0.0066) but this difference was lost after manipulation (TTC 24.31 mm(2), PTC 25.97 mm(2)). Thus cannula manipulation had no effect on wound area and an adverse effect on maximum wound length for the threaded cannula only. Despite movement, the muscle damage score remained significantly less for the threaded cannula.

Abdominal Wall↗

PubMed2000

An in vitro evaluation of a new cannula tip design compared with two clinically established cannula-tip designs regarding aortic arch vessel perfusion characteristics.

We investigated in vitro aortic arch vessel perfusion characteristics of single and multiple jet-stream cannulae and a new dispersion stream tip aortic cannula. Pressures and flows of all arch vessels were measured while directing cannulae jets at the different arch vessels using 6 l/min pump flow. The highest increase in pressure above the set systemic level of 80 mmHg and increase in flow above the set normal flow distribution in the arch vessels occurred in the jet-streamed arch vessels with the single stream cannula. The values were as follows: 29 mmHg and 118 ml/min for the innominate artery, 28 mmHg and 42 ml/min for the left common carotid artery, and 25 mmHg and 54 ml/min for the left subclavian artery. The dispersion stream cannula showed increases in pressure and flow, followed by the multiple stream cannula. Aortic cannula tips and the orientation of jets are potential sources of imbalances of arch vessel perfusion with possible clinical implications regarding perfusion of arch vessels during extracorporeal circulation.

Aorta↗

PubMed2002

Intraabdominal pressure and incision parameters associated with a pyramidal laparoscopic trocar-cannula system and the EndoTIP cannula.

STUDY OBJECTIVE: To compare intraabdominal pressure and incision characteristics associated with insertion of a disposable pyramidal trocar-cannula system (T-CS) and the EndoTIP threaded cannula, a trocarless, reusable laparoscopic access device. DESIGN: Randomized trial (Canadian Task Force classification I). SUBJECTS: White swine. INTERVENTION: . Six insertions were created on the lower abdomen of 10 animals; changes in intraabdominal pressure associated with insertion of the pyramidal T-CS and threaded cannula were recorded by a computerized system. Once insertions were completed, skin and subcutaneous tissues were dissected to expose fascial wounds. MEASUREMENTS AND MAIN RESULTS: Incision length and wound area and muscle damage scores were determined. The mean change in intraabdominal pressure for the pyramidal T-CS was 4.44 mm Hg and for the threaded cannula was 2.76 mm Hg (p = 0.0001). Mean incision length, mean wound area score, and mean muscle damage score for the pyramidal T-CS were 0.968 cm, 30.9 mm(2), and 1.9/4, respectively, and for the threaded cannula they were 0.699 cm (p = 0.0082), 17.0 mm(2) (p = 0.0066), and 0.7/4 (p = 0.001), respectively. CONCLUSION: In this model, insertion of the threaded cannula created less change in intraabdominal pressure and smaller fascial and muscle defects than insertion of the pyramidal T-CS.

Abdomen↗

PubMed1998

Laparoscopic cannula cone with means for cannula stabilization and wound closure.

A reusable cone suitable for use with existing laparoscopy cannulas was designed to provide means for sealing and stabilizing the operative site throughout the procedure, and for repairing the surgical site after the surgery is completed. The device consists of a moveable laparoscopic cannula cone fitted with suture holders. The cone contains tunnels terminating at its distal end that serve as passages for sutures loaded on a special needle to traverse the abdominal wall. When sutures are pulled into suture holders they stabilize the cannula and seal the puncture site. When sutures are tied at the end of the procedure, they achieve full-thickness closure of the operative site. The laparoscopic cannula cone stabilizes the cannula on the abdominal wall, maintains an air-tight seal, controls potential hemorrhage from the cannula puncture site, and achieves satisfactory closure of the surgical defect. Preliminary experience with the instrument and method has been most satisfactory.

Equipment Design↗

PubMed1993

Serial long-term assessment of in vivo LHRH release from a discrete area of the ewe median eminence using multiple guide cannula assembly and removable push-pull cannulae.

Analysis of neuronal interactions at the median eminence (ME) that control anterior pituitary function requires sampling of in vivo release of specific hypophysiotropic components and of putative inputs that might regulate such a release. We developed a multiple guide cannula assembly (MGCA) to sample repetitively discrete areas of the ewe ME, using removable push-pull cannula (PPC) probes. The MGCA is attached to the skull over the ME using stereotaxic surgery. A specific guide cannula of the assembly (1 of 48 guides) located on the midline and directly on top of the central portion of the ME is selected based on roentgenograms obtained after infusion of radiopaque contrast material into the third ventricle. The MGCA and the large size of the ewe brain allows the simultaneous positioning of a PPC probe, an infusion cannula or another removable probe in additional discrete hypothalamic and extrahypothalamic areas. To determine the capabilities of this sampling technique, we assessed in vivo release of LHRH from the extracellular space at the posterior-lateral ME, under various reproductive conditions that have well-defined LH-secretory patterns. The pulsatile profile of both LHRH and LH was significantly lower in anestrus than during the follicular phase of cycling ewes. In vivo pulsatile release of LHRH was higher in the follicular than in the midluteal phase of ewes sampled repetitively from the same ME site during three consecutive estrous cycles. All ewes showed increased midluteal progesterone levels. In vivo LHRH release, as determined by PPC sampling of the extracellular fluid at the posterior-lateral ME, probably reflects a mix of hypophysiotropic and nonhypophysiotropic LHRH components. Histological analysis revealed a well-organized, pallisade-like array of astroglial processes along the track of chronically implanted cannulae. This glial scar is disrupted along the tracks of acutely reimplanted cannulae but without apparent difference in the yield of the method. Our method increases the efficiency and versatility of ME PPC sampling providing an additional tool to assess the role of the ME as the final neuroendocrine control site of anterior pituitary function.

Animals↗

PubMed1989

Cannula thrombophlebitis: a study in volunteers comparing polytetrafluoroethylene, polyurethane, and polyamide-ether-elastomer cannulae.

Cannulae made of polytetrafluoroethylene (PTFE: n = 11), thermoplastic polyether-urethane (TPEU: n = 11), and a new test material, polyamide-ether-elastomer (XLON: n = 10) were inserted into the veins of the dorsum of the hand in 32 healthy volunteers (10 women and 22 men), 21-50 years old. The cannulae were intended to be left in place for 5 days. No infusion was given and the dressings were not exchanged. The resulting thrombophlebitis, defined as two or more of the symptoms pain, redness, oedema and hardness, was estimated on a scale which took into account the incidence, location, intensity, and duration of the symptoms. Except for one volunteer in the XLON group, all the volunteers developed thrombophlebitis, generally observed on the third day of cannulation, and being more frequent and intense over the cannulae (P less than 0.001) and at the tip (P less than 0.01) than at the insertion sites. Pain and oedema were, on the whole, the most frequent and severe symptoms during the period of indwelling. After withdrawal, hardness was the most intense, and together with pain, the most long-lasting (up to 10 days) symptom. The differences between the materials in thrombophlebitis incidence and intensity were statistically significant only when each symptom was analysed separately. Thus, the PTFE cannulae caused more pain and hardness (probably because of greater platelet adhesion and a relatively greater stiffness), while the TPEU and XLON cannulae produced more periphlebitis (redness and oedema), probably because of potentially irritant and antigenic substances leaking from them (polyurethane oligomers and polyamide/polyethyleneglycol oligomers).

Adult↗

PubMed1999

Variables affecting convection-enhanced delivery to the striatum: a systematic examination of rate of infusion, cannula size, infusate concentration, and tissue-cannula sealing time.

OBJECT: Although recent studies have shown that convection can be used to distribute macromolecules within the central nervous system (CNS) in a homogeneous, targeted fashion over clinically significant volumes and that the volume of infusion and target location (gray as opposed to white matter) influence distribution, little is known about other factors that may influence optimum use of convection-enhanced distribution. To understand the variables that affect convective delivery more fully, we examined the rate of infusion, delivery cannula size, concentration of infusate, and preinfusion sealing time. METHODS: The authors used convection to deliver 4 microl of 14C-albumin to the striatum of 40 rats. The effect of the rate of infusion (0.1, 0.5, 1, and 5 microl/minute), cannula size (32, 28, and 22 gauge), concentration of infusate (100%, 50%, and 25%), and preinfusion sealing time (0 and 70 minutes) on convective delivery was examined using quantitative autoradiography, National Institutes of Health image analysis software, scintillation analysis, and histological analysis. Higher rates of infusion (1 and 5 microl/minute) caused significantly (p < 0.05) more leakback of infusate (22.7+/-11.7% and 30.3+/-7.8% [mean+/-standard deviation], respectively) compared with lower rates (0.1 microl/minute [4+/-3.6%] and 0.5 microl/minute [5.2+/-3.6%]). Recovery of infusate was significantly (p < 0.05) higher at the infusion rate of 0.1 microl/minute (95.1+/-2.8%) compared with higher rates (85.2+/-4%). The use of large cannulae (28 and 22 gauge) produced significantly (p < 0.05) more leakback (35.7+/-8.1% and 21.1+/-7.5%, respectively) than the smaller cannula (32 gauge [5.2+/-3.6%]). Varying the concentration of the infusate and the preinfusion sealing time did not alter the volume of distribution, regional distribution, or infusate recovery. CONCLUSIONS: Rate of infusion and cannula size can significantly affect convective distribution of molecules, whereas preinfusion sealing time and variations in infusate concentration have no effect in this small animal model. Understanding the parameters that influence convective delivery within the CNS can be used to enhance delivery of potentially therapeutic agents in an experimental setting and to indicate the variables that will need to be considered for optimum use of this approach for drug delivery in the clinical setting.

Animals↗

PubMed1982

A prospective trial comparing a silicone elastomer intravenous cannula (Visis) with a polytetrafluoroethylene cannula (Cathlon).

Post-infusion phlebitis remains one of the most frequent causes of hospital morbidity with an incidence varying between 13 and 39 per cent (1-4). A recent study indicated that a silicone elastomer cannula (Visis) had desirable properties (5). We have carried out a prospective trial comparing the value of such a cannula with a Teflon cannula (Cathlon) already in routine use.

Catheterization↗

PubMed1975

[A new cannula for the introduction of catheters or other cannulas into the vascular system].

A new cannula is described consisting of a 25 cm. tube without a syringe attachment. It can be used for the introduction of other annuals (Hettler method) or for guide wires (Seldinger technique). The use of this cannula instead of the usual means of introducing catheters makes it possible to learn the technique quickly and to achieve correct placing of the cannula in the vascular lumen. The radiologist, using this method, achieves a safe and routine method very quickly. In this way angiographic examinations are made simpler they can be performed more quickly and the number of complications is reduced.

Angiography↗

PubMed1992

[A holder for right-angled metal cannula (Pacifico's venous cannula) for direct superior vena caval cannulation].

In pediatric open heart surgery, a right-angled metal cannula (Pacifico's venous cannula) for direct superior vena caval cannulation is frequently used. But it is often difficult to be inserted into superior vena cava due to "right-angled" shape especially in small babies. We developed a new holder which can make straight line from the metal tip to flexible plastic end of the cannula. It is easy and safe even in cases of small babies.

Catheterization, Central Venous↗