Atrial Cannulation Research Articles

Gastric tonometry and venous oximetry in cardiac surgery patients

To determine the relationship between gastric intramucosal pH and several other indices of splanchnic perfusion in patients undergoing cardiopulmonary bypass. Prospective, single-arm study. University Hospital. Elective cardiac surgery patients (n = 8), free of hepatic disease, were studied. Before anesthetic induction, a triple-lumen, heparin-bonded fiberoptic catheter was inserted into the hepatic vein under fluoroscopic guidance. An identical catheter was inserted into the pulmonary artery. After endotracheal intubation, a nasogastric tube modified to permit measurement of gastric intramucosal pH was inserted into the stomach. Systemic oxygen delivery (DO2), and arterial, mixed venous, hepatic venous, and femoral venous blood gases and lactate concentrations were recorded at the following times: immediately before induction of anesthesia (time 1); during atrial cannulation (time 2); after 30 mins of hypothermic cardiopulmonary bypass (time 3); 15 mins after termination of cardiopulmonary bypass (time 4); and 1 hr after arrival in the ICU (time 5). Hepatic venous hemoglobin saturation (SO2) and mixed venous hemoglobin saturation (SvO2) were monitored continuously from times 1 to 5. Gastric intramucosal pH was recorded at times 2, 3, 4, and 5. The hepatic catheter was removed as soon as the last samples were collected in the ICU. The square of the weighted mean correlation coefficients (rw)2 for gastric intramucosal pH vs. hepatic venous lactate concentrations, gastric intramucosal pH vs. hepatic venous PO2, and gastric intramucosal pH vs. hepatic venous pH were (rw)2 = .50, (rw)2 = .58, and (rw)2 = .32, respectively. Systemic DO2, hepatic venous lactate concentrations, hepatic venous PO2, and hepatic venous pH were significant determinants in the multiple regression model for gastric intramucosal pH (r2 = .89). There were significant differences between SvO2 and hepatic venous SO2 at times 4 and 5. Gastric intramucosal pH may provide a minimally invasive way to monitor the adequacy of splanchnic DO2 in patients undergoing cardiopulmonary bypass. Additional data are necessary to determine whether low gastric intramucosal pH is truly a marker of supply-dependent oxygen uptake across the hepatosplanchnic vascular bed under these conditions.

Transatrial Interruption of the Inferior Vena Cava

Transatrial placement of a Greenfield filter at the time of cardiac surgery was performed on three patients with recent femoral venous thrombosis and unstable angina, and at the time of pulmonary embolectomy on four others. The filter carrier was passed through the right atrial cannulation site under fluoroscopic guidance into the inferior vena cava. A preliminary venacavogram was performed through the carrier or a previously placed angiographic catheter. Two complications were encountered: the first was misplacement of a filter in the right renal vein before routine venacavography was employed; the second was caudal displacement of a filter by a right atrial venous drainage cannula that projected into the inferior vena cava. The latter complication can be prevented by the use of a right atrial "sump" drain that does not protrude into the inferior vena cava.

Distant organ procurement in clinical lung- and heart-lung transplantation *1Cooling by extracorporeal circulation or hypothermic flush

The scarcity of suitable donors for single lung and heart-lung transplantation calls for methods of medium-term pulmonary preservation to allow for distant organ procurement. At our institution, the first five grafts (four heart-lung, one single lung) were cooled by means of a transportable extracorporeal circulation unit, while the last eight grafts (four heart-lung, four single lung) were flush-perfused with modified cold Euro-Collins solution. The technique of extracorporated circulation included aortic and right atrial cannulation and cooling to 12 degrees-14 degrees C (rectal temperature) using a bubble oxygenator. Bypass times ranged between 41 and 52 min. Following excision, the organs were transported in ice-cold donor blood for ischemic times from 171 to 310 min. For cold flush preservation, simultaneous coronary (cold St. Thomas's solution) and pulmonary artery perfusion (Euro-Collins solution, 50 ml/kg over 4 min) were initiated simultaneously. The organs were transported in cold Euro-Collins solution for ischemic times of 175 to 270 min. In heart-lung transplantations the first postoperative arterial PO2 upon arrival at the intensive care unit was 120 +/- 38 Torr in the extracorporeal circulation and 140 +/- 38 Torr in the Euro-Collins solution group. Six of eight patients were extubated within 48 h after cardiopulmonary grafting. We conclude that pulmonary function following heart-lung or single lung preservation with simple hypothermic flush is as good or better than that following extracorporeal circulation. Since distant organ retrieval is much more convenient without the latter, preservation using Euro-Collins solution is preferred.

Scanning electron microscopy evaluation of the Abiomed 5000 ventricular support system after clinical biventricular assistance

Twenty-nine days after implantation of an Abiomed 5000 biventricular support system for otherwise intractable end-stage cardiomyopathy, the inner surfaces of the device were examined by means of scanning electron microscopy (SEM). SEM showed clean surfaces inside the blood sacs, with only rare fibrin deposits. There were platelet adhesions on the ventricular side of the artificial atrioventricular valves; no deposits were on the opposite side. Structural deterioration of the closing edge of the artificial valves could be seen. The tubing system was likewise covered by a uniform deposition of single platelets with no major thrombus formation. Postmortem examination of the patient, on the other hand, revealed gross thrombus formation inside both atria at the cannulation sites, despite efficient anticoagulation. We conclude that the Abiomed 5000 per se is unlikely to be the site of major thrombus formation leading to subsequent embolization after 660 h implantation. However, the structural integrity of the adapting areas of the leaflets may become a point of concern. Further research is necessary to improve the atrial cannulation technique in order to prevent the atrial thrombus formation demonstrated as the source of systemic embolization.

Simplified method for reoperation on the mitral valve

Reoperation on the mitral valve is becoming more common because of the degeneration of bioprosthetic valves, endocarditis, and malfunction or thrombosis of mechanical valves. We advocate a technique that transforms a technically difficult operation into one that is much less tedious, time-consuming, and dangerous than reopening a sternal-split operative site the second, third, or fourth time. Favorable experience in 11 patients using right anterolateral thoracotomy without aortic or right atrial cannulation and without aortic cross-clamping or cardioplegia is presented.

Venous Bypass for Surgical Resection of Renal Carcinoma Invading the Vena Cava: A New Approach

Summary— A new technique is described which facilitates the surgical removal of renal carcinoma from the inferior vena cava. The use of cardiopulmonary bypass with or without cardiac arrest has been advocated but with this procedure only the inferior vena cava is bypassed, using femoral and right atrial cannulation, assisted by a closed system electromagnetic centrifugal pump. In appropriate cases this less complex technique allows prolonged access to the inferior vena cava whilst providing equal protection from pulmonary embolisation and tumour dissemination; it also reduces morbidity, operating time, difficulty and cost when compared with cardiopulmonary bypass.

Radionuclide Assessment of the Natural Heart Ejection Fraction before and after LVAD Implantation

Complete pressure unloading of the ventricles can preserve ischemically damaged myocardium. Most clinical left heart assist device (LVAD) systems used after ischemic injury of the heart apply atrial cannulation which does not ensure pressure unloading. In order to assess the effect of the implantation of an intracorporeal LVAD on the function of the natural heart, we determined the ejection fraction (EF) in four male Holstein calves (90-105 kg) before and after insertion of a Cleveland Clinic pneumatic LVAD. A gated blood pool scan was obtained with a gamma camera after injection of 40 mCi Tc-labelled albumin. The animals were restrained in a sling to avoid movement artifacts. All animals showed a drop of 65 +/- 12% to 42 +/- 14% EF in the first postoperative (p.o.) week. Left ventricular output did not maintain sufficient blood pressure as assessed by pump-off tests. Systolic blood pressure dropped from 122 +/- 6.5 mm Hg to 81 +/- 6 mm Hg without pump support on the morning of the first p.o. day. Apical coring and possible restrained heart movement by the implanted LVAD may lead to impaired myocardial function that renders the individual LVAD dependent until adaptative corrections take place.

Surgery depresses pulsatile growth hormone release in rats for up to 2 days.

In order to study the pulsatile release of rat growth hormone in a stress-free environment, many investigators obtain sequential blood samples from individual rats bearing an indwelling, right atrial cannula. There has been little systematic study of the stressful effects of the cannulation procedure on the pulsatile release of rat growth hormone. We examined the acute and chronic effects of right atrial cannulation on growth hormone release in male rats by monitoring plasma growth hormone concentration at every 2 min. Right atrial cannulation was performed under ether anaesthesia. Blood was collected from the rats for a 2 h period (11.00-13.00 h), either immediately following, or 2, 3 or 7 days following the surgery. When blood was collected 7 days after surgery, growth hormone was released in large bursts. The amplitude of these bursts however, did not differ significantly from the bursts of growth hormone in rats cannulated 3 days prior to blood collection. On the other hand, the bursts of hormone release in rats cannulated immediately or 2 days before blood collection were significantly smaller in amplitude than those in rats cannulated 3 days before collection, but were not significantly different from each other. In many of the rats cannulated immediately before or 2 days before blood collection, pulsatile growth hormone release was completely suppressed. The results of the study suggest that blood sampling from right atrial cannulae to measure the plasma concentration of rat growth hormone should not be carried out until at least 3 days after the cannulation procedure.

Use Of A Ventricular Assist Device In Postcardiotomy Shock

To assess the current status of ventricular assist device (VAD) support of patients with postcardiotomy ventricular failure, we evaluated the data from 20 patients treated with the Pierce-Donachy paracorporeal pneumatic sac-type VAD using atrial cannulation and asynchronous pumping. All patients had severe ventricular failure refractory to intra-aortic balloon (IAB) and drug therapy. The effects of the VAD on ventricular function were evaluated by nuclear ventriculography and hemodynamic measurements during brief pump-on/pump-off periods. Although the VAD reduced left ventricular preload, ejection fraction decreased as afterload increased, suggesting that asynchronous left atrial pumping does not unload the left ventricle.

Experimental and clinical results with a simplified left heart assist device for treatment of profound left ventricular dysfunction.

AbstractDuring the last few years patients with profound heart failure following cardiac surgery have been managed with increasing success with the use of a variety of left heart assist devices. Although some previous experimental studies suggested that cannulation of the left ventricle was superior to that of the left atrium, present studies demonstrate that left atrial cannulation can effectively unload the left ventricle, and significantly decrease left ventricular work. Since 1978, a roller pump type of left heart assist device with cannulation of the left atrium and ascending aorta has been employed in 46 patients with severe postoperative cardiac failure. Twenty‐one patients were successfully weaned from the device; 5 patients died within 90 days of removal of the device, and there were 2 other late deaths 4 months and 4 years postoperatively. There were 14 long‐term survivors (6 months to 54 months). Thirteen of these patients are New York Heart Association class I or II, and 1 patient is New York Heart Association class III. Thus, satisfactory early and late results can be attained with this system. However, it has been postulated that if more complete left heart bypass were utilized, more patients would ultimately survive.

Noncardioplegic myocardial preservation for coronary revascularization

Hypothermic potassium cardioplegia has become the most popular technique for myocardial preservation during coronary revascularization. However, an older technique continues to yield comparable results with some potential advantages. Myocardial preservation was achieved with systemic hypothermia to 28 degrees C, pericardial cooling, elective ventricular fibrillation, maintenance of systemic perfusion pressure between 80 and 100 mm Hg, routine left ventricular venting, and local vessel isolation during distal anastomoses without aortic occlusion. Proximal anastomoses were performed prior to atrial cannulation and cardiopulmonary bypass. Nonemergency isolated bypass grafting was performed in 500 consecutive patients, of whom 51% had had a prior myocardial infarction, 24% had unstable angina, and 21% had left main coronary stenosis. Primary grafting was performed in 483 patients and reoperations in 17. The mean number of grafts per patient was 3.8. Perioperative myocardial infarction occurred in 1.8%. Hospital mortality was 0.4%. Late follow-up was obtained for all survivors at a mean postoperative interval of 17.8 months. All survivors were asymptomatic or improved over their preoperative status. The 3 year actuarial survival rate was 95.8%, equivalent to that for the matched general population. Of 287 male patients under age 65, 68.4% were working preoperatively and 69.5% postoperatively. This technique provides results comparable to bypass grafting with cardioplegia and may be useful when aortic occlusion or administration of cardioplegic solutions is not desirable.

Survival and complications following ventricular assist pumping for cardiogenic shock.

Thirty patients (pts) have undergone ventricular assist pumping for up to 25.4 days (mean 6.8 days). Twenty-eight pts could not be weaned from cardiopulmonary bypass (CPB) after open heart operations and two pts sustained myocardial infarctions (MI), with cardiogenic shock unresponsive to medical therapy previous to surgery. Twenty-two pts required left ventricular assistance (LVA); 55% (12/22) were weaned from the pump and 32% (7/22) survived. Two pts required right ventricular assistance (RVA); both were weaned from the pump and survived. Six pts required right and left ventricular assistance (BVA) and none survived. Postoperative survival for program years 1976 through 1979 (14 pts) was 14% (2/14). Postoperative survival for program years 1980 through 1982 (16 pts) was 44% (7/16), reflecting improved pump insertion techniques (left atrial cannulation) and pt management. Since 1980, 12 pts have required LVA, nine have been weaned from the pump, and six pts have survived (50%). One pt has required RVA and has survived, and three pts requiring BVA did not survive. Seven pts have been alive and well 5, 9, 14, 19, 24, 30 and 36 months after surgery. Five are NYHA functional Class I status and two pts are NYHA Class II status. Current data indicates that single ventricular assistance in pts who cannot be weaned from CPB is "reasonable and therapeutic treatment to extend life."

Cardiovascular responses to verapamil during coronary artery bypass graft surgery.

The cardiovascular effects of verapamil administration during coronary artery bypass graft surgery were studied in patients with normal left ventricular function. Anesthesia consisted of morphine, diazepam, and nitrous oxide. Before atrial cannulation for cardiopulmonary bypass, 16 patients received either verapamil (N = 8) 0.075 mg X kg-1 or an equal volume of its solvent (N = 8) administered intravenous over 1 min. Hemodynamic functions and serum verapamil levels were measured over the succeeding 10 min. Verapamil produced rapid reductions in systemic vascular resistance, systemic arterial blood pressure, and left ventricular stroke work index. The PR interval increased slightly and two of the patients who had a baseline PR interval of 200 msec developed a mild first degree heart block. Heart rate, cardiac index, pulmonary capillary wedge pressure, central venous pressure, and right ventricular stroke work index did not significantly change. No measured cardiovascular functions changed in the control group. Serum verapamil levels peaked at 346.4 +/- 143.5 ng X ml-1 0.5 min after drug administration and then rapidly declined. Both groups of patients tolerated surgery and the immediate postoperative recovery period without hemodynamic compromise. Verapamil can be safely administered before cardiopulmonary bypass in patient with good left ventricular function during narcotic-based anesthesia.

Distribution of oxygenated blood by transseptal left atrial cannulation during lung support in the open-chest model

The hemodynamic characteristics and anatomic configuration of the aortic root determine the extent of coronary bed filling by the desaturated blood ejected by the left ventricle during conventional lung support with extracorporeal membrane oxygenation (ECMO), unless turbulence is created close to the coronary ostia by high-flow bypass ratios (greater than 80% of cardiac output) or ascending aorta cannulation. Using a total right heart bypass preparation, we studied the effect of returning blood transseptally into the left atrium upstream to the coronary arteries by means of a specially designed double-lumen cannula inserted via the jugular vein. Desaturated blood was used in six dogs ventilated with 100% oxygen (Group A), and oxygenated blood was used in 10 hypoxic dogs (Group B). We observed homogeneous mixing of oxygenated and desaturated blood at wide ranges of bypass flow ratios (20 to 80%) as determined downstream to the left atrium, i.e., left ventricle, coronary artery branch, root of the aorta, and descending thoracic aorta. Adequate coronary oxygenation (PO2 greater than or equal to 60 mm. Hg) was obtained with 40% of cardiac output oxygenation, a flow that could be met with a single superior vena cava (SVC) cannula through the major lumen of such a cannula. Total avoidance of high-pressure arterial cannulation and homogeneous distribution of oxygenated blood, regardless of the bypass flow ratio, by this technique are obvious advantages not available with conventional ECMO cannulations.

Cholinergic control of the nocturnal prolactin surge in the pseudopregnant rat.

The possible involvement of cholinergic mechanisms in the control of rhythmic secretion of prolactin has been examined in the pseudopregnant rat. Baseline data were obtained in decapitated animals in which the diuranl surge was observed in the 1430--2030 h range and the nocturnal surge during the 2330-0530 h interval. Atrial cannulation permitted a faithful reproduction of the prolactin pattern seen in decapitated rats if at least 3 days elapsed between the cannulation operation and bleeding, while cardiac puncture, under light ether anesthesia, appeared to suppress the diurnal surge. This latter observation appeared to depend on the time of sampling in relation to the onset of the dark phase of the daily lighting cycle. Atropine (35 or 70 mg/100 g BW) was found to inhibit the nocturnal surge in animals bled by either the cardiac puncture or cannulation techniques --an effect which was reversed by pretreatment with eserine (50 or 100 mug/100 g BW). Nicotine (0.75 mg/100 g BW) was found to delay, but not completely to inhibit, the nocturnal surge. When evaluated in the light of other available information, these observations suggest that a complex cholinergic mechanism is involved in control of the nocturnal rhythm of prolactin in pseudopregnancy and that the two surges, diurnal and nocturnal, are differentially controlled.

Reoperation After Insertion of Aortic Homograft as a Right Ventricular Outflow Tract

Three patients who developed pseudoaneurysm or stenosis of the right ventricular outflow tract after insertion of an aortic homograft between the right ventricle and the pulmonary artery presented the technical problems at reoperation of intimate adherence of the homograft to the sternum. Successful replacement of the defective aortic homograft was accomplished by sequentially employing peripheral venous and arterial cannulation, heart-lung bypass, hypothermia, circulatory arrest, sternotomy, right atrial cannulation, and resumption of bypass.

Left ventricular bypass in the dog. A technique employing transthoracic cannulation and a paracorporeal roller pump.

Ten dogs underwent temporary left ventricular bypass for four hours. Cannulation of the left atrium was performed by the closed-chest transthoracic method, and the output of a small air-driven paracorporeal roller pump was delivered into the left carotid artery. Bypass flow rates ranged from 19 to 55 ml/kg/min. Hemodynamics, blood gases, pH, and serum electrolyte levels remained normal throughout the entire bypass period. No pneumothorax or hemothorax was observed at autopsy one week later. The punctured wall of the left atrium healed well. Transthoracic left atrial cannulation is a safe and reliable method if proper precautions are observed. This technique may have clinical application in circulatory support following cardiac operation.

Controlled cardiac output studies in dogs. II. "Controlled caval return preparation" for the purpose of varying the cardiac output in the closed-chest intact dog.

Refinements in the technique of performing the "control caval return preparation" were outlined, such as those which enable one to control the caval return in the closed-chest intact dog for an arbitrary period of time, at the end of which atrial cannulation and re-establishment of caval flow were accomplished without re-entry into the chest cavity. These latter two maneuvers were accomplished by using a self-constricting rubber band to seal off the atrium and eyed stainless steel wires to release the sutures about the cavae. Coronary flow was estimated by the previously described regression equation and the value added to the known value for '' caval return'' to give a value which was called the "estimated cardiac output." The experiment was conducted sterilely, in order to study survival. It would appear that dogs in this experiment could withstand a reduction in the "caval return" to as low a value of "estimated cardiac output" as 25 ml./Kg./min. The total peripheral vascular resistance was easily calculated, owing to the fact that a close '' estimate of the cardiac output" was obtainable throughout the period of reduced "caval return." The response in "the total peripheral vascular resistance" (TPVE) was most marked during the two-hour period of reduced "caval return," in the range of estimated cardiac output 20 to 40 ml./Kg./min., when there occurred a progressive increase in the TPVR. Above this range, the TPVR remained relatively unchanged throughout the period of control. Below this range the TPVR rose slight^, then began to fall before the end of the controlled period.Refinements in the technique of performing the "control caval return preparation" were outlined, such as those which enable one to control the caval return in the closed-chest intact dog for an arbitrary period of time, at the end of which atrial cannulation and re-establishment of caval flow were accomplished without re-entry into the chest cavity. These latter two maneuvers were accomplished by using a self-constricting rubber band to seal off the atrium and eyed stainless steel wires to release the sutures about the cavae. Coronary flow was estimated by the previously described regression equation and the value added to the known value for '' caval return'' to give a value which was called the "estimated cardiac output." The experiment was conducted sterilely, in order to study survival. It would appear that dogs in this experiment could withstand a reduction in the "caval return" to as low a value of "estimated cardiac output" as 25 ml./Kg./min. The total peripheral vascular resistance was easily calculated, owing to the fact that a close '' estimate of the cardiac output" was obtainable throughout the period of reduced "caval return." The response in "the total peripheral vascular resistance" (TPVE) was most marked during the two-hour period of reduced "caval return," in the range of estimated cardiac output 20 to 40 ml./Kg./min., when there occurred a progressive increase in the TPVR. Above this range, the TPVR remained relatively unchanged throughout the period of control. Below this range the TPVR rose slight^, then began to fall before the end of the controlled period.