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Biomedical subjects

S R Gundry

Publications and source records attributed to S R Gundry.

At least 91 records · Page 5Linked to original sources
PubMed1990

Facile retrograde cardioplegia: transatrial cannulation of the coronary sinus.

The benefits of coronary sinus (CS) cardioplegia are well known, yet CS cardioplegia is not used widely owing to the need for bicaval cannulation, snares, and an atriotomy. We designed and used in 225 consecutive patients a catheter containing a flexible removable stylet that, when shaped into a hockey-stick configuration, enabled blind intubation of the CS through a small pursestring in the right atrium, guided easily into the CS using a finger on the atrioventricular groove at the inferior vena cava. The CS was intubated in all patients; a pressure-limited balloon at the catheter tip was inflated after cross-clamping. An integral distal pressure line measured CS pressure. Catheters were placed distally within the great cardiac vein beyond the posterior interventricular vein; the position did not alter cooling: right ventricular free wall, septum, and left ventricular free wall temperatures were 7 degrees +/- 2 degrees, 8 degrees +/- 2 degrees, and 7 degrees +/- 2 degrees C, respectively, after an initial 10 mL/kg of blood cardioplegia. Transatrial CS cardioplegia was used in 45 aortic valve replacements, 22 mitral valve replacements, 4 triple-valve replacements, 6 congenital lesions, and 148 coronary revascularizations, including 40 redo operations. Atheromatous material was routinely flushed retrogradely from cut old vein grafts during revascularization; 70 revascularizations (47%) were performed urgently for acute infarction or jeopardized myocardium. No heart block or CS injury occurred, and inotrope use dropped to 10% of patients (from 38% in the previous 256 patients with antegrade blood cardioplegia). We conclude that the CS can be cannulated transatrially and that CS cardioplegia is more facile than antegrade cardioplegia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Hypoplastic left heart syndrome.

HLHS is a complex developmental malformation of the left ventricle, aorta, and associated valves. Survival beyond neonatal life is the exception in untreated infants. The prognosis, however, is no longer hopeless. Newer surgical strategies of staged palliative reconstruction and heart replacement by transplantation appear promising. These options on occasion will become complementary in the management of individual patients. Those children surviving Fontan operations are frequently able to lead NYHA Class I or II lives without drugs, while transplant recipients will require one or more immunoregulative medications indefinitely. Exercise tolerance and work capacity following the Fontan procedure are reported to be 40 to 60 per cent of expected normals. Full functional capacity of successfully palliated children may never be normal. In contrast, exercise capability after heart transplantation is generally better than that following a Fontan operation, with cardiac ejection fractions approaching normal for age. Durability of these new management technologies will make inappropriate the traditional "do nothing" approach to HLHS in all but a few cases.

Decision Trees↗
PubMed1989

Postoperative conduction disturbances: a comparison of blood and crystalloid cardioplegia.

Conduction system disturbances after cardioplegia are well described. Our four-man group changed in mid-1987 from standard crystalloid cardioplegia (35 mEq/L of KCl) to blood cardioplegia (4 parts blood to 1 part cardioplegia) (18 mEq/L of KCl) based on experimental and clinical evidence that blood cardioplegia provides better myocardial protection. Shortly thereafter, we anecdotally noted increased conduction abnormalities. This prompted us to compare serially all patients undergoing coronary artery bypass grafting during 1987 for perioperative and late conduction system disturbances after either crystalloid or blood cardioplegia. Surgeons and techniques including topical cooling did not differ. Forty-one (23%) of 179 patients with crystalloid cardioplegia had conduction disturbances versus 141 (49%) of 289 patients with blood cardioplegia (p less than 0.001). Perioperative complete heart block requiring atrioventricular sequential pacing occurred in 20 patients with crystalloid cardioplegia versus 67 patients with blood cardioplegia (p less than 0.002), and atrioventricular block requiring permanent pacing was present in 4 and 12 patients (p less than 0.001), respectively. Left bundle-branch block was found in 8 patients given crystalloid cardioplegia and 28 patients with blood cardioplegia (p less than 0.05); right bundle-branch block, 12 and 68 patients (p less than 0.001); left anterior hemiblock, 8 and 37 patients (p less than 0.001); and interventricular conduction delay, 15 and 53 patients (p less than 0.005), respectively. Bifascicular block occurred in 4 patients receiving crystalloid cardioplegia versus 23 receiving blood cardioplegia (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Postoperative bleeding in cardiovascular surgery. Does heparin rebound really exist?

Postoperative bleeding following cardiovascular procedures is troublesome and often life-threatening. The effect of heparin (H) is usually reversed with protamine sulfate (P) at the end of vascular procedures; subsequent bleeding or abnormal coagulation times are ascribed to so-called heparin rebound and are treated with extra empiric doses of P. H rebound has heretofore been described only by using biologic clotting tests, which are often abnormal postoperatively. Thus, many instances of postoperative bleeding are treated with inappropriate and dangerous doses of P in the mistaken impression that more H needs to be reversed. Using the new test for plasma H, the azure A Assay, which measures H chemically rather than biologically, 27 patients were tested after cardiac bypass surgery to determine whether H rebound truly exists. Azure A levels of H were measured before the bypass procedure and every half hour from 0-8 hours after bypass in routine coronary artery bypass patients. Tests for prothrombin time (PT) and partial thromboplastin time (PTT) were performed simultaneously. The azure A test was performed on 252 samples of blood in the 27 patients; only one sample drawn anytime except immediately after bypass contained measurable H (0.4%). This sample became negative for H in the ensuing 30 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Azure Stains↗
PubMed1988

A reversible pulmonary artery band: preliminary experience.

Pulmonary artery banding has become an infrequently used surgical technique. However, if a band was developed that could be relieved without the need for open heart surgery, it is likely that pulmonary artery banding would be used more frequently in the management of infants with congenital heart disease. Such a pulmonary artery band was placed in seven 1 week old mongrel puppies by using a loop of an absorbable suture material (Vicryl). One dog died at 2 months as a result of right ventricular failure. The remaining six dogs underwent cardiac catheterization and pulmonary balloon angioplasty at 6 months of age. After measuring pulmonary artery, right ventricular and aortic pressures and performing a right ventricular angiogram, balloon angioplasty of the band site was performed. A 20 mm balloon angioplasty catheter (Medi-Tech) was used in all dogs. Balloon angioplasty decreased right ventricular pressure from 101 +/- 19 to 42 +/- 3 mm Hg (p less than 0.05) and right ventricular systolic outflow tract gradient from 59 +/- 14 to 7 +/- 2 mm Hg (p less than 0.03), and increased the size of the band site from 8.7 +/- 0.03 to 14.9 +/- 0.5 mm (p less than 0.01). All dogs were recatheterized 2 months after angioplasty and were then killed for pathologic evaluation. At follow-up catheterization, right ventricular pressure, right ventricular outflow tract gradient and pulmonary artery size at the band site remained at the values obtained immediately after angioplasty. Postmortem examination demonstrated that there was no evidence of pulmonary artery damage. Although these studies are preliminary, they suggest that a reversible pulmonary artery band can be performed.

Angioplasty, Balloon↗
PubMed1988

Experimental repair of ventricular septal defects using autologous right ventricular muscle flaps: preliminary report.

Survival after repair of postinfarction ventricular septal defects remains poor, often due to extensive loss of contractile muscle in the septum or left ventricle. We evaluated whether a contractile flap of right ventricular muscle could be used to repair a similar ventricular septal defect to augment left ventricular performance in 7 fully instrumented mongrel dogs (weight, 23 to 28 kg). By using hypothermic bypass and cold fibrillatory arrest, a trapezoidal right ventricle flap was fashioned from the free wall of the mid to lower right ventricle, basing its widest portion anteriorly on the septum and left ventricle. A large, 2-cm-diameter core of septum was excised beneath this flap to simulate a postinfarct ventricular septal defect. The right ventricular flap was then invaginated through the defect and sewn to the left ventricular side of the septum with pledgeted sutures taken full thickness through the flap and septum in a "vest-over-pants" fashion. Contraction of the right ventricular flap was confirmed visually and by postbypass multiple gated acquisition scans. The right ventricular defect was closed with fascia lata. All dogs were weaned from bypass without inotropes. Precardiac and postcardiac outputs of 2.5 +/- 0.5 versus 2.3 +/- 0.4 L/min and left ventricular end-diastolic pressures of 4 +/- 2 versus 4 +/- 3 mm Hg were identical. No shunts were detected by oxygen saturation. Autopsies confirmed the integrity of the repair. We conclude that septal defects can be repaired by using contractile right ventricular muscle, thus preserving left ventricular function. This technique offers promise for repair of postinfarction ventricular septal defects by using autologous, already conditioned to contract, cardiac muscle, but its application in humans must await long-term testing.

Animals↗
PubMed1988

Surgical creation of a double outlet right atrium for tricuspid valve stenosis after a Rastelli operation.

A patient with transposition of the great arteries, ventricular septal defect, and obstruction of the left ventricular outflow tract underwent a Rastelli repair. Stenosis of the tricuspid valve was not recognised before or during operation; this severely compromised the postoperative haemodynamic function and necessitated reoperation. Insertion of a second homograft from the right atrium to the right ventricle bypassed the stenosis and resulted in a complete recovery with maintenance of a biventricular circulation.

Child↗
PubMed1987

A quantitative and qualitative comparison of fibrin glue, albumin, and blood as agents to pretreat porous vascular grafts.

Recent reports suggest that fibrin glue can be used to seal porous vascular grafts prior to insertion, but this ability has not been quantitatively compared to existing methods. We compared blood loss from and handling characteristics of grafts pretreated with either fibrin glue (FG) (Tisseel), albumin autoclaving (AA), or blood preclotting (BP). Five 6-cm segments of 6-mm internal diameter grafts, both knitted and woven double velour Dacron were treated in each group (30 specimens). Human blood was forced through the BP group until clotted; AA segments were soaked in 25% human albumin and autoclaved for 10 min; FG segments were treated with a topical application of Tisseel (0.5 ml/graft) followed by treatment with topical thrombin + CACl (0.5 ml/graft). Graft ends were sealed and attached to a transducer/syringe pump mechanism which pumped heparinized human blood into the graft at 100 mm Hg intraluminal pressure. All blood that leaked through the grafts over 2 min was collected and the amount was averaged for the five grafts in each group. Graft handling was characterized as either pliable or stiff. Blood pretreatment caused 21 +/- 2 and 13 +/- 4 cc/2 min of leak in knitted and woven grafts, respectively. Albumin autoclaving resulted in 9 +/- 2 and 1 +/- 0.5 cc of leak (P less than 0.01 compared to blood), while fibrin glue produced 2 +/- 2 and 0.4 +/- 0.5 cc leaks (P less than 0.01 compared to blood). Both blood and fibrin glue produced soft pliable grafts, while albumin pretreatment resulted in stiff grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMed1986

Prognostic factors in valvotomy for critical aortic stenosis in infancy.

Aortic valvotomy for critical aortic stenosis in infancy has had a high mortality. To determine the factors that influence survival, we reviewed the cases of 24 infants who underwent aortic valvotomy in the first 6 months of life (mean 4 1/2 weeks) for aortic stenosis from 1978 to 1984. Cardiopulmonary bypass was used in all patients. Operative mortality was 21% (5/24), four of the five deaths occurring from low cardiac output. Analysis of preoperative factors affecting survival versus nonsurvival revealed that low ejection fraction (60% +/- 17% in survivors versus 36% +/- 2% in nonsurvivors), high left ventricular end-diastolic pressure (16 +/- 7 mm Hg in survivors versus 30 +/- 14 mm Hg in nonsurvivors), and presence of endocardial fibroelastosis (25% in survivors versus 100% in nonsurvivors) all were predictive of a poor outcome, although the small sample size indicated caution in interpreting results. Factors that did not appear to influence survival included peak systolic gradient (79 +/- 30 mm Hg in survivors versus 60 +/- 15 mm Hg in nonsurvivors) and left ventricular end-diastolic volume (37 +/- 17 cm3/m2 in survivors versus 36 +/- 7 cm3/m2 in nonsurvivors). Four patients with a left ventricular end-diastolic volume below 26 cm3/m2 survived. Postoperative gradients averaged 25 +/- 21 mm Hg at 3.4 +/- 2 years' follow-up in nine recatheterized patients. Ejection fraction of these patients increased from 45% +/- 10% to 70% +/- 11% and left ventricular end-diastolic volume increased from 37 +/- 17 to 58 +/- 5 cm3/m2. Two of 17 patients have required apical-aortic conduits; all other patients are asymptomatic. We conclude that infants with critical aortic stenosis benefit from valvotomy even with impaired left ventricular function and severely reduced left ventricular dimensions and many have nearly normal hemodynamics on late follow-up.

Age Factors↗
PubMed1985

Esophageal motor dysfunction in an adult with a congenital tracheoesophageal fistula.

A preoperative barium esophagogram and esophageal manometry in an adult patient with an H-type congenital tracheoesophageal fistula revealed the typical esophageal motor abnormalities previously described following operative repair of esophageal atresia in infants. The upper esophageal sphincter contracted normally, the lower esophageal sphincter relaxation was weak and incomplete, and there was no active peristaltic wave within the esophagus. These findings support the theory that the abnormal esophageal motor function reported after repair of congenital tracheoesophageal fistula and esophageal atresia is on a congenital basis and is not directly attributable to operative trauma or denervation.

Aged↗
PubMed1984

Efficacy of preoperative biliary tract decompression in patients with obstructive jaundice.

Fifty consecutive matched patients with benign or malignant biliary tract obstruction were compared to determine the efficacy of preoperative percutaneous biliary drainage (PBD). Twenty-five patients underwent PBD for an average of nine days before operation; 25 patients underwent percutaneous transhepatic cholangiography ( PTHC ) followed immediately by operation. Serum bilirubin levels before PTHC were 16.5 +/- 7.6 mg/dL and 14.9 +/- 7.6 mg/dL in PBD and non-PBD groups, respectively. Serum bilirubin levels decreased to 6.5 +/- 6.2 mg/dL preoperatively in patients having PBD. One week after operation, bilirubin levels were 4.2 +/- 4.3 mg/dL and 9.0 +/- 5.2 mg/dL in the PBD and non-PBD groups, respectively. Major morbidity (sepsis, abscess, renal failure, or bleeding) occurred in two patients (8%) having PBD and in 13 patients (52%) without PBD. One patient (4%) with PBD, and five patients (20%) without PBD, died. The mean hospital stay was shorter for the PBD group. Preoperative PBD reduces operative mortality and morbidity and results in a more rapid resolution of hyperbilirubinemia during the postoperative period.

Biliary Tract Surgical Procedures↗
PubMed1984

Traumatic pseudoaneurysms of the thoracic aorta. Anatomic and radiologic correlations.

Long-term survivors with traumatic ruptures of the aorta that are not detected at the time of injury manifest pseudoaneurysms. We reviewed a ten-year experience with pseudoaneurysms of the thoracic aorta to correlate anatomic and roentgenographic findings in this unusual group of patients. Eleven patients, who were 28 to 65 years of age, had abnormal chest findings one to 36 years after their injuries. Nine patients had calcification that was visible on the plain chest film, and two patients had calcification that was visible on computed tomography. Nine of the 11 pseudoaneurysms, all of which were distal to the left subclavian artery, were saccular and involved only the medial aspect of the aortic wall. Anatomically, they appeared to have been confined in a space bordered by the mediastinal pleura, pulmonary artery, left mainstem bronchus, and normal aorta. Pseudoaneurysms that occur on the medial aortic wall at the level of the ligamentum arteriosum may be more stable because of anatomic confinement by stable adjacent structures.

Adult↗