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Biomedical subjects

M J Reardon

Publications and source records attributed to M J Reardon.

At least 55 records · Page 3Linked to original sources
PubMed1998

Surgical myocardial revascularization.

In conclusion, surgical myocardial revascularization has utilized diverse methods to increase blood flow to the starving myocardium. These methods initially used the microcirculation as the portal to reach myocytes until angiography showed that the obstructions were macrovascular. This resulted in a 30-year era of direct attack on the coronary blockages by coronary bypass. Surgical conduits unfortunately have longevity considerably less than that of native arteries and are limited in number. Alternative conduits, both biologic and prosthetic, have not yet proved to have the same clinical results as the ITA. More patients are living long enough to have the extensiveness of their disease exhaust conventional therapies. Newer therapy, restricted thus far to untreatables, revisits the microcirculation by making laser channels. These many innovative procedures have benefited hundreds of thousands of patients. They emerged from the probity and innovation of many individual surgeons.

Angina Pectoris↗
PubMed1998

Thoracic and thoracoabdominal aortic aneurysm repair using cardiopulmonary bypass, profound hypothermia, and circulatory arrest via left side of the chest incision.

PURPOSE: Although some authors advocate hypothermic circulatory arrest for spinal cord protection in descending thoracic and thoracoabdominal repair, this method has been associated with high morbidity and mortality rates in other studies. The safety and effectiveness of this surgical adjunct were evaluated. METHODS: Between February 1991 and April 1997, 409 patients underwent thoracic or thoracoabdominal aortic repair. Because of an inability to gain proximal aortic control because of anatomic or technical difficulty, hypothermic circulatory arrest was used in 21 patients (4.9%). Thirteen patients were men, 8 were women, and the median age was 57 (range, 21 to 81 years). Four patients (19%) had Marfan's syndrome, and 1 had aortitis. Seven patients (33%) had aortic dissection (4 chronic type A, 2 chronic type B, 1 acute B), and 1 had aortic laceration. All but 6 patients had hypertension. Fifteen patients (73%) were operated on for repair of the distal arch and descending thoracic aorta, 4 (19%) for repair of the distal arch and thoracoabdominal aorta, and 2 for repair of either the thoracoabdominal or descending thoracic aorta alone. Surgery for 9 patients (43%) also included bypass grafts to the subclavian or innominate arteries. Six operations (29%) were urgent. RESULTS: The overall 30-day mortality rate was 29% (6 of 21 patients). Among urgent patients, the mortality rate was 50% (3 of 6 patients) versus 20% (3 of 15) for elective patients. Of the remaining 15 patients, renal failure occurred in 1 (7%) and heart failure in 2 (13%). Ten patients (67%) had pulmonary complications. Encephalopathy occurred in 5 patients (33%) and stroke in 2 (13%), and spinal cord neurologic deficit developed in 2 (13%). The median recovery was 28 days (range, 10 to 157 days). CONCLUSION: Hypothermic circulatory arrest did not reduce the incidence of deaths and morbidity to a rate comparable with our conventional methods. We recommend the judicious application of this method in rare instances when proximal control is not feasible or catastrophic intraoperative bleeding leave the surgeon with no other option.

Adult↗
PubMed1998

Evolving experience with cryopreserved mitral valve allografts.

Allograft valves have been used for aortic valve replacement (AVR) for 35 years with excellent results. Early attempts at mitral valve replacement (MVR) with mitral valve allograft were unsuccessful mainly due to technical issues of measurement of appropriate graft size, difficulty of reimplantation, and early dehiscence of the papillary muscle anastomosis. Recently, interest in this procedure has been rekindled by successful laboratory experiments with mitral valve allograft implantation and improved understanding of the mitral valve apparatus from extensive mitral valve repair experience. In this article, we discuss the rationale for allograft use, the historical perspective of allograft use, and technical problems, along with current solutions and clinical outcomes of MVR with mitral valve allograft. Tricuspid valve replacement (TVR) with allograft mitral valve also is briefly discussed.

Animals↗
PubMed1998

Minimally invasive valve surgery.

Minimally invasive surgical techniques have proliferated at a staggering rate in the last decade. Cardiac surgery has been a late entrant in this process but is currently experiencing a surge of interest in and techniques for minimally invasive approaches. Cardiac valve surgery has seen a rapid and ongoing evolution of minimally invasive approaches that, it is hoped, will decrease patient discomfort, operative morbidity, length of hospitalization, and cost, improve cosmetic healing, and facilitate return to normal function while not compromising short- or long-term outcomes of the surgical procedure. This article examines the evolution of recent experience with minimally invasive valve surgery and emphasizes the surgical considerations surrounding 1) the choice of incision, 2) access techniques for cardiopulmonary bypass (CPB), 3) methods of myocardial protection, 4) techniques for aortic occlusion, and 5) atrial incisions for exposure of the mitral valve. The results of early and currently available series are also reviewed.

Cardiopulmonary Bypass↗
PubMed1998

Flight performance effects of thermal stress and two aviator uniforms in a UH-60 helicopter simulator.

The effects on flight performance of the four combinations of an unencumbered mission oriented protective posture (MOPP) aviator battle dress uniform (ABDU) and encumbered MOPP4 over ABDU flight ensemble in cool (70 degrees F or 21.1 degrees C, 50% relative humidity [RH]) and hot (100 degrees F or 37.8 degrees C, 50% RH) UH-60 simulator cockpit conditions were evaluated with a repeated measures, 2 x 2 factorial study using nine crews. The encumbered MOPP4 uniform had the most frequent adverse effect on flight performance followed by heat stress, with less frequent effects from the combination or interaction of these two factors. This study confirmed that heat stress and wearing an encumbered U.S. Army MOPP4 flight uniform significantly reduced endurance and flight performance in a UH-60 simulator.

Adult↗
PubMed1998

Mitral valve injury from blunt trauma.

Mitral valve injury from blunt trauma to the chest is an uncommon entity. We report a case of mitral valve injury after a fall, and its repair. The English literature is reviewed from the earliest report in 1873 to the present. The diagnosis, types of injury and surgical correction are discussed.

Accidental Falls↗
PubMed1997

Heterotopic calcification in abdominal wounds.

BACKGROUND: Heterotopic bone formation in abdominal incisions is a recognized but uncommon sequela of abdominal surgery. The condition of heterotopic bone formation in the abdominal scar may not only cause physical and/or emotional discomfort for the patient but also mimic a retained foreign body or recurrence of a malignant condition. All cases of two surgeons representing a wide variety of general and thoracic surgery were reviewed, and three primary cases and one recurrent case of heterotopic bone formation in an abdominal wound were identified. These cases are compared with the cases available in the English literature to enhance the recognition, appropriate diagnosis, and treatment options available for the patient with this unusual condition. METHODS: All cases for two surgeons representing a variety of general and thoracic surgery were reviewed. Three patients with painful heterotopic calcification of an abdominal incision requiring excision were identified. One patient had undergone an upper midline laparotomy for pancreatitis and the other two had undergone median sternotomy for cardiac surgery. One of these patients developed a painful recurrence of upper linea alba calcification. All patients were male and ranged in age from 51 to 74 years. Primary heterotopic calcification of the upper linea alba occurred between 2 and 4 months for all patients. All cases were treated with excision and primary tissue closure. The case of recurrent calcification occurred 1 1/2 months after primary closure, and was treated with re-excision and 1,200 centirads of postoperative radiotherapy to the incision area over 3 days, starting on postoperative day 1. The 2 cases of primary heterotopic calcification successfully treated with the initial excision have been followed for 2 and 6 years respectively without recurrence. The case of recurrent heterotopic calcification treated with re-excision and postoperative radiotherapy has been followed for 10 months without recurrence.

Abdomen↗
PubMed1997

Ischemic left ventricular free wall rupture: prediction, diagnosis, and treatment.

Left ventricular free wall rupture is the third leading complication and the second most common cause of death after myocardial infarction. Its occurrence has been considered an unpredictable event usually leading to death. An increased appreciation for the clinical presentation of this syndrome and the nearly ubiquitous use of echocardiography have fostered a rise in the antemortem diagnosis of left ventricular free wall rupture, allowing the possibility of operative repair. Despite the increased reporting of left ventricular free wall rupture, the experience of any one surgeon or surgical group tends to be quite small. We review the current status of rupture prediction, clinical presentation, diagnosis, and treatment options. A recent case of left ventricular free wall rupture referred to the Baylor Cardiothoracic Surgery Group with the misdiagnosis of ruptured dissection of the ascending thoracic aorta is presented to illustrate our approach to this clinical situation.

Heart Rupture, Post-Infarction↗
PubMed1997

CT reconstruction of an unusual chronic posttraumatic aneurysm of the thoracic aorta.

Chronic traumatic aneurysm of the thoracic aorta is an unusual occurrence. Previously, arteriography was performed on all patients seen in our institution with this entity to allow confirmation of the diagnosis and anatomic delineation for operation. A case of chronic traumatic aneurysm of the distal descending aorta discovered on a routine chest roentgenogram and evaluated with chest computed tomographic scanning with three-dimensional reconstruction is presented. It is our belief that not all thoracic aneurysms require arteriography, and improved methods of computed tomographic scanning allow adequate diagnosis and anatomic delineation with decreased morbidity and cost.

Accidents, Traffic↗
PubMed1997

Allograft valves for aortic and mitral valve replacement.

Allograft valves have been used in cardiac valve replacement for 35 years. During much of this time, certain centers have used allograft aortic valves for aortic valve replacement and have reported excellent long-term results. After an initial period of failure using allograft mitral valves for mitral valve replacement, the technical problems of papillary muscle dehiscence and mitral regurgitation appear minimized by current investigators who now report encouraging early results. The current status of allograft use for aortic and mitral valve replacement is reviewed.

Aortic Valve↗
PubMed1997

A method for open reduction and internal fixation of the unstable posterior sternoclavicular joint dislocation.

Posterior sternoclavicular joint (SCJ) dislocations are most often stable after reduction but may be associated with significant complications related to the location of the medial head of the clavicle within the mediastinum. In rare instances, a posterior SCJ dislocation is irreducible or redislocates after a closed reduction. Because of the potential hazards related to compression of vital structures within the superior mediastinum, open reduction and internal fixation is usually required. Although open reduction is widely accepted as the method of choice, the best method for achieving stable fixation remains unanswered. We present the case of an unstable SCJ stabilized, in anatomic position, with two large-bore cannulated screws in conjunction with open reduction. We believe that the risk of hardware migration reported with the use of pins and wires and its catastrophic complications are greatly minimized using our technique.

Adult↗
PubMed1997

Eccrine syringofibroadenoma surrounding a squamous cell carcinoma: a case report.

A 91-year-old man presented with a 9.0 x 7.0 cm exophytic mass on the dorsum of the right foot, surrounded by a scaling hyperkeratotic plaque-like lesion that had been present for many years. He had similar long-standing hyperkeratotic plaque-like lesions on both legs. Histopathologic examination of the exophytic mass revealed a well-differentiated squamous cell carcinoma surrounded by an eccrine syringofibroadenoma (ESFA). Histochemistry, immunohistochemistry and electron microscopy support this diagnosis. To our knowledge, this is the only reported case of ESFA being intimately associated with a malignant neoplasm.

Adenoma, Sweat Gland↗
PubMed1997

Applications of predictive environmental strain models.

Researchers at the U.S. Army Research Institute of Environmental Medicine have developed and validated numerical models capable of predicting the extent of physiologic strain and adverse terrain and weather-related medical consequences of military operations in harsh environments. A descriptive historical account is provided that details how physiologic models for hot and cold weather exposure have been integrated into portable field advisory devices, computer-based meteorologic planning software, and combat-oriented simulation systems. It is important that medical officers be aware of the existence of these types of decision support tools so that they can assure that outputs are interpreted in a balanced and medically realistic manner. Additionally, these modeling applications may facilitate timely preventive medicine planning and efficient dissemination of appropriate measures to prevent weather- and altitude-related illnesses and performance decrements. Such environmental response modeling applications may therefore be utilized to support deployment preventive medicine planning by field medical officers.

Algorithms↗
PubMed1997

Coronary artery bypass conduits: review of current status.

Coronary artery bypass grafting (CABG) is the most common procedure performed in adult cardiovascular surgery today. In our Department of Surgery at Baylor College of Medicine, we have experienced, as have most large programs, a trend to older patients, more comorbidity, worse ventricular function, and more redo CABG procedures. Along with this shift has come an evolution in surgical techniques, cardioplegia and choice of coronary bypass graft conduits. The benefit of using an internal mammary artery (IMA) to the left anterior descending coronary artery (LAD) appears irrefutable at this time. Data for multiple arterial grafts is still evolving and conduit choice for other than the IMA to LAD graft is often debated. The purpose of this article is to review the current literature on conduit choice and to allow a rational, data driven approach to graft choice.

Adult↗
PubMed1996

Left ventricular rupture following mitral valve replacement.

Left ventricular rupture following mitral valve replacement is an unusual and often lethal complication. Despite being well described since the initial description in 1967 by Roberts, this catastrophic complication still occurs. A recent case of a delayed Type III rupture is presented. The pathology and repair of the three recognized types of rupture are reviewed and the preventive measures discussed.

Aged↗
PubMed1994

U.S. military working dogs with Vietnam service: definition and characteristics of the cohort.

We verified and corrected inaccuracies in descriptive profile information on military working dogs (MWDs) that died from 1965 to 1980 and were reported in the Armed Forces Institute of Pathology Registry of Veterinary Pathology. Using other available military records, we determined which dogs served in Vietnam. Identified were 3,895 MWDs with a unique identity tattoo that served in Vietnam, of which 2,389 served exclusively with U.S. military forces and died in Vietnam. Another 479 Vietnam veteran MWDs completed their service elsewhere. This overall effort resulted in signalment corrections, generally age at death, in 21% of the Registry MWD accessions during the study period. The improved definition and characterization of the Vietnam cohort will lead to greater precision in epidemiologic investigations of the health effects from the Vietnam experience in U.S. military working dogs.

Animals↗