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Biomedical subjects

T M Schmahl

Publications and source records attributed to T M Schmahl.

16 recordsLinked to original sources
PubMed2001

Purely internal thoracic artery grafts: outcomes.

BACKGROUND: Most of our patients with coronary artery disease have undergone bypass exclusively with purely internal thoracic artery grafts (PITA). Our goal has been to lengthen the time a patient benefits from coronary bypass operations. The present report describes an 8.5-year study of outcomes including mortality and the need for reintervention in patients who have undergone bypass with PITA. METHODS: We studied 897 patients who underwent PITA with a total of 3,784 internal thoracic artery (ITA) grafts (4.2 grafts per patient). Connecting ITA to ITA along with sequential anastomosis made the procedure possible. RESULTS: Early mortality for the group was 2.3%. Freedom from death was 86% and freedom from reintervention was 94% at 5 years after the operation. CONCLUSIONS: The acceptable early and late mortality and the 94% freedom from reintervention as long as 8.5 years after operation in this group of patients inspire us to continue choosing PITA for patients with three-vessel coronary artery disease.

Adult↗
PubMed1998

Transition from cardiopulmonary bypass to the HeartMate left ventricular assist device.

BACKGROUND: Safe transition from cardiopulmonary bypass to the HeartMate left ventricular assist device without periods of low output, air emboli, or injury to the right ventricle is vital to its successful implantation. A right atrial-to-left ventricular shunt has been developed to purge quickly and completely all air from the system and prevent its reentry, as well as to assist the right ventricle during the transition from cardiopulmonary bypass to the HeartMate. METHODS: From January 1994 through July 1996, we used an extracorporeal membrane oxygenation right atrial-to-left ventricular shunt during 17 HeartMate implantations in 16 patients. The shunt consists of the existing right atrial two-stage cannula, the bypass circuit, and a separate aortic line that fills the left ventricle using a 21F cannula in the lateral ventricular wall. Air is monitored in the heart and aorta using transesophageal echocardiography. RESULTS: Ten of the 16 patients are living and 8 have undergone transplantation. Two patients are still using the device and are awaiting transplantation. None of the patients have experienced postoperative neurologic events suggestive of air emboli. CONCLUSIONS: The extracorporeal membrane oxygenation right atrial-to-left ventricular shunt is simple and inexpensive to construct. It provides for a smoother and safer transition from cardiopulmonary bypass to the HeartMate left ventricular assist device.

Cardiopulmonary Bypass↗
PubMed1996

Complete revascularization with internal thoracic artery grafts.

Saphenous vein graft atherosclerosis continues to be the major cause of late failures of coronary artery bypass operations (CABG). The internal thoracic artery (ITA) is an ideal bypass graft because it remains free of atherosclerosis at late follow-up in most patients. Myocardial revascularization with only ITA grafts has developed in an incremental manner from single grafts of the left ITA to the left anterior descending coronary artery (LAD), to use of bilateral, free and sequential ITAs, and now recently to the use of preconstructed grafts that attach the free right ITA to the left ITA. The microanatomy and vascular reactivity of the ITA have been recently defined, and they explain why the ITA remains free of obstruction. Our techniques and results of ITA grafting developed over the past 25 years are presented.

Anastomosis, Surgical↗
PubMed1995

Reoperation in patients with closed SVG and patient LITA-LAD graft: T-graft approach.

Selection of the bypass graft that the patient has demonstrated will remain patent and free from critical atherosclerosis is a most important part of coronary artery bypass reoperations. Sixteen patients in whom a patent left internal thoracic artery-left anterior descending coronary artery bypass graft and obstructed or closed saphenous vein grafts to other coronary arteries were visualized underwent reoperation. To reach the inadequately perfused circumflex and right coronary arteries, the right internal thoracic artery was anastomosed to the left internal thoracic artery as a T graft and then was attached to the circumflex and right coronary artery branches. All patients survived the procedure and are free from angina. There were no perioperative myocardial infarctions, and there was no suggestion of hypoperfusion by the grafts. We believe this technique may reduce the incidence of graft failure in patients undergoing reoperative coronary artery bypass grafting.

Adult↗
PubMed1994

Total revascularization with T grafts.

The T graft is constructed by anastomosing the proximal end of the free right internal thoracic artery to the side of the attached left internal thoracic artery. Besides adding considerable reach to the right internal thoracic artery, this technique allows the left anterior descending coronary artery and its branches to be bypassed with the attached left internal thoracic artery. Two hundred eight-seven patients, aged 34 to 86 years (mean age, 64.6 years) received an average of 4.4 internal thoracic artery to coronary artery anastomoses. Sixty-nine patients had left main disease, 33 were undergoing first-time reoperations, and two were reoperated on for the second time. Ejection fraction ranged from 0.20 to 0.70. Operative mortality was 1.7%. Twenty-six patients had postoperative graft visualization, and 94.7% of the grafts were open. All 45 bypass grafts from the left internal thoracic artery were patent, and 91% of those from the right internal thoracic artery were unobstructed. This procedure requires technical skill with internal thoracic arteries, but it has the potential of significantly improving long-term event-free survival and reducing the need for reoperation in patients undergoing coronary artery bypass grafting.

Adult↗
PubMed1994

T-graft: a new method of coronary arterial revascularization.

We present early results in 486 patients undergoing total coronary artery revascularization using a T-graft constructed from the attached left internal thoracic artery (LITA) and the free right internal thoracic artery (RITA). The anterior and anterolateral areas of the heart are by-passed with the LITA and the inferolateral, inferior and posterior areas are by-passed with the RITA. These patients received an average of 4.34 distal anastomoses with as many as four from each of the limbs of the T-graft. Ages ranged from 29 to 89 years and ejection fractions from 15 to 79%. Sixty-six patients were undergoing first reoperations and 6 received T-grafts at their second reoperation. The mortality at 30 days was 2.3%. Two of 92 women and 9 of 394 men expired. The perioperative infarction rate was 1.2%. Postoperative angiography in 34 patients showed 98.3% of LITA and 86.5% of RITA anastomoses to be patent. There was a slightly higher patency observed in women. The T-graft technique can be applied to nearly all patients with 3 vessel coronary artery disease with low operative mortality. Precise technique with high power magnification is crucial. This procedure has the potential of avoiding further invasive procedures due to graft deterioration in many patients with 3 vessel coronary artery disease.

Adult↗
PubMed1989

Aortic annular tear after valvuloplasty: the role of aortic annulus echocardiographic measurement.

Following percutaneous transluminal aortic valvuloplasty, 2/100 patients (2%) developed significant aortic insufficiency as a result of an aortic annular tear. Both patients underwent emergency aortic valve replacement and survived the operation. One patient died 4 weeks postoperatively from sepsis and multiorgan failure, and the other patient had a benign postoperative course. In both cases, the balloon area significantly exceeded the aortic annular area and caused the complication. Review of the balloon area-aortic annular area ratio in our series showed that a value of less than 1.2 was not associated with this complication.

Aged↗
PubMed1989

Sequential, free and Y internal thoracic artery grafts.

The internal thoracic artery (ITA) has excellent durability and its ability to survive for 10 years or more far exceeds the saphenous vein graft (SVG). In an attempt to improve long-term survival from coronary artery bypass grafting (CABG), three or more (up to six) ITA coronary anastomoses have been placed in 718 patients since 1982. Initial flow in the ITA immediately after grafting is critical to the success of the operation. Careful dissection and preparation of the ITA pedicle to prevent injury and spasm, constructing parallel and perpendicular anastomoses so the most proximal portion of the ITA is used for anastomosis and the use of the free right ITA to increase length of graft available are measures employed to increase critical flow. Actuarial survival at 6 years is 92.5% in this group of patients, which includes elderly patients, patients with left ventricular dysfunction and patients undergoing emergency operations.

Adult↗
PubMed1986

Measures to increase the number of mammary artery coronary artery anastomoses.

Patients with single internal mammary artery (IMA) grafts along with saphenous vein grafts have been found to have fewer coronary events and longer survival after operation. To reduce bypass graft failure from intimal hyperplasia and atherosclerosis, as well as to improve results, three or more IMA grafts were placed in 215 patients from October 1982 through May 1985. Careful planning helped in bypassing the maximum number of coronary artery obstructions with arterial conduits. By using bilateral IMA grafts, sequential, and Y grafts, the number of IMA coronary artery anastomoses increases and the need for saphenous vein grafts decreases. Meticulous dissection and preparation of the entire IMA and proper construction of the anastomosis are essentials for these procedures to be successful. Two of the 215 patients died early and four died late. Ninety-five percent of the postoperative stress tests were negative and 92% of the 39 IMA grafts visualized in 13 patients studied postoperatively were patent. We found this to be a safe, challenging procedure that improved late bypass conduit success and prolonged survival.

Journal Article↗
PubMed1986

Expanding the use of the internal mammary artery to improve patency in coronary artery bypass grafting.

To improve the early and late benefits from coronary artery bypass grafting, we have expanded the use of the internal mammary artery by bypassing three or more coronary arteries with mammary grafts. Experience with higher power magnification and the use of the single internal mammary artery are necessary prerequisites of this procedure. The first 100 patients who had three or more mammary artery-coronary artery anastomoses are reviewed. Eighty-six patients received three mammary-coronary anastomoses, 13 received four, and one received six. An average of 3.2 internal mammary artery grafts and 1.7 saphenous vein grafts per patient were placed. Twenty-five of 27 mammary grafts were open on postoperative graft visualization. There were no early deaths and only one patient died late of complications of gangrene of the lower extremities. None of the patients had significant left ventricular failure and only three had perioperative myocardial infarctions. None of the patients complain of angina and 58 of 59 postoperative stress tests were normal. This procedure should significantly reduce the late closure of bypass grafts and the complications thereof, including the need for reoperation.

Coronary Artery Bypass↗
PubMed1984

Techniques for multiple internal mammary artery bypass grafts.

Long-term patency of the internal mammary artery graft surpasses that of all other bypass conduits. The use of multiple internal mammary artery grafts should improve the long-term results following coronary artery bypass grafting. Technical factors used in mobilizing, preparing, and anastomosing the internal mammary artery are discussed in this article. Fifty-three patients received sequential attached left internal mammary artery grafts from April, 1982, to August, 1983. In 6 of these patients, the right internal mammary artery was anastomosed to a circumflex marginal branch. There were no operative deaths or instances of low cardiac output. One patient suffered anastomotic narrowing that possibly could have been prevented by excision of excess tissue from the internal mammary artery pedicle. Multiple internal mammary artery grafting should have a profound influence on the results of coronary artery bypass grafting.

Graft Survival↗
PubMed1984

Percutaneous transluminal coronary angioplasty in patients with prior coronary artery bypass grafting.

Percutaneous transluminal coronary angioplasty (PTCA) has been used to treat patients with prior coronary artery bypass grafting who have stenosis of a saphenous vein graft and/or a native artery. During 53 months, 61 patients underwent 105 angioplasty attempts. Eighty lesions (76%) were successfully dilated in 46 of 61 patients (75%). Success in a patient was determined by a greater than or equal to 20% decrease in the percent diameter stenoses coupled with an improved clinical response; 52 patients had one prior CABG and nine patients had two or more prior CABGs. Multivessel disease was present in 56 patients (92%). A vein graft stenosis was successfully dilated in 26 of 33 cases (79%)--19 of 25 (76%) at an anastomotic site and seven of eight (88%) in the graft body. An arterial stenosis was successfully dilated in 37 of 52 cases (71%)--18 of 22 (82%) in the left anterior descending, 13 of 22 (59%) in the circumflex, 21 of 26 (81%) in the right coronary, and two (100%) in the left main coronary artery. There is no statistically significant difference in the incidence of success in dilating a vein graft or native artery. Complications included: one emergency CABG (1.6%), three myocardial infarctions (4.9%), and two deaths (3.3%). There were 15 unsuccessful PTCAs: Ten patients had elective CABG, one had emergency CABG, two received medical treatment, and two died. Forty-six patients are being followed-up: Twenty-eight (61%) continue to do clinically well, seven (15%) had another PTCA and remain well, and 10 (16%) had elective CABG because of restenosis and/or disease progression. There was one late death and one late myocardial infarction. Thus, 35 patients (57%) had continued clinical success without the need for repeat CABG; 89% had no angina or improved angina, and 90% had improved exercise treadmill results. PTCA is technically feasible in selected patients with prior CABG and can achieve a clinical response with an acceptable complication rate when compared to repeat CABG.

Angina Pectoris↗
PubMed1984

The role of the sequential internal mammary artery graft in coronary surgery.

The use of sequential internal mammary artery grafts is a possible method of improving overall long-term graft patency in patients receiving coronary artery bypass grafts. Twenty-nine patients who had sequential grafts were studied. The left internal mammary artery was anastomosed side-to-side to the diagonal and end-to-side to the left anterior descending coronary artery (LAD) in 24 patients, side-to-side to the proximal LAD and end-to-side to the distal LAD for proximal and midvessel obstruction in four patients, and in one patient the left internal mammary artery was grafted side-to-side to the first marginal branch of the circumflex artery and end-to-side to the second marginal branch. There were no operative deaths, but one patient died 10 months after surgery from viral pneumonia. There was no evidence of left ventricular failure. None of the patients suffered perioperative myocardial infarction or return of their angina. Eleven patients underwent postoperative stress tests and results were negative in all. Graft visualization in three patients showed patent grafts without kinking or narrowing. These findings suggest that the sequential internal mammary artery graft is safe and should improve overall long-term patency. We particularly recommend its use in the younger patient.

Coronary Artery Bypass↗
PubMed1983

The internal mammary artery graft: the best choice for bypass of the diseased left anterior descending coronary artery.

The atherosclerotic plaque that critically obstructs the proximal left anterior descending coronary artery is three times more likely to produce a fatal myocardial infarction than lesions in the other coronary arteries. Severe obstruction in a bypass graft to the proximally stenosed left anterior descending artery is probably at high risk of provoking a fatal infarction. Selection of the bypass graft with adequate flow and the greatest longevity is of great importance. Review of 298 patients who received internal mammary artery grafts illustrates that this bypass has excellent long-term patency, minimal attrition, and little evidence suggesting late atherosclerotic formation. Difficulties with anastomosis and pedicle injury during preparation (the most frequent reasons for internal mammary artery failure) can be reduced to 2% or less by introducing magnification and microsurgical techniques. The properly prepared internal mammary artery graft has the longest lasting patency and should be used when bypassing proximal left anterior descending lesions.

Adult↗
PubMed1981

The internal mammary artery graft. Its longevity after coronary bypass.

Two hundred ninety-eight patients who received internal mammary artery (IMA) grafts were reviewed seven to nine years after surgery; 91.6% of these patients are still alive. In 29.5% of these patients there was postoperative graft visualization, and 90% of the studies were performed because of suspected graft failure. Attrition of the IMA graft was minimal. At zero to 24 months after surgery, 93.4% of grafts were patent. At 60 to 108 months 94.4% were patent and there was little, if any, evidence of atherosclerosis in the IMAs. Precise technique in preparation and anastomosis of the IMA is essential for long-term patency. For bypassing obstructive lesions, we recommend selection of the IMA (if it has sufficient size and flow) for use in the left anterior descending, large diagonal, or marginal vessel in the left coronary artery circulation.

Adult↗