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Biomedical subjects

F Robicsek

Publications and source records attributed to F Robicsek.

At least 109 records · Page 6Linked to original sources
PubMed1992

Surgical treatment of ventricular tachycardia with Nd:YAG laser photocoagulation.

BACKGROUND: Directed surgery for the definitive treatment of drug resistant ventricular tachycardia (VT) due to coronary artery disease carries a significant operative mortality. Surgical failure to cure VT remains a problem, especially in patients without anterior left ventricular myocardial infarcts and aneurysms. A method has been developed in which Nd:YAG laser is used to photocoagulate myocardium responsible for the initiation of VT using a "sequential" approach intended to improve operative results and gain insight into the variable substrates causing VT. METHODS: Under normothermic cardiopulmonary bypass, VT is induced and then extensive endocardial and epicardial mapping performed to localize and characterize that form of VT. Nd:YAG is applied to the areas of myocardium from which that form of VT originates until it disappears and is no longer inducible. Next attempts are made to induce other forms of VT and when successful, mapping and lasing repeated until finally VT is no longer inducible. RESULTS: Fifty-one patients were operated on and have been followed for at least 1 year. Operative mortality in 12 patients with preoperative ejection fractions less than 20% was 41%; in 39 patients with ejection fractions greater than 20% operative mortality was 8%. Eighty-eight percent of the 43 operative survivors are free of recurrent sustained VT at 1 year. There have been no arrhythmic mortalities. In a group of 30 patients evaluated for epicardial VT, 9 of 14 patients with inferior infarcts without left ventricular aneurysms had at least one form of epicardial VT. CONCLUSIONS: Nd:YAG laser photocoagulation of myocardial VT using a sequential approach is a viable method that permits an ongoing study of this entity. Operative mortality remains high in patients with diffusely poor left ventricular function. Epicardial VT is frequent in patients with inferior infarcts and may account for inferior results in these patients when conventional endocardial approaches are used alone.

Adult↗
PubMed1992

The history of right heart bypass before Fontan.

Numerous clinical and experimental studies have suggested that adequate pulmonary blood flow and normal central venous pressure may be maintained without significant contribution of right ventricular function. These data induced experimental and clinical research in the quest for complete bypass of the right heart. More than 40 different operations have been designed to bypass the right ventricle. Partial right ventricular bypass was achieved in 1949 by anastomosing the superior vena cava to the pulmonary artery in animal experiments. In 1950 such as operation was successfully performed clinically for the first time. Complete bypass of the right heart was accomplished for the first time experimentally in 1954 by performing a superior vena cava-to-right pulmonary artery anastomosis and implanting the inferior vena cava into the left atrium. Successful clinical bypass of the right heart was carried out later by implanting both vena cavae into the pulmonary circulation. Until the cavopulmonary shunt conclusively proved the validity of the concept that compensated circulation is possible without participation of the right ventricle, surgeons did not fully understand its possible relevance in clinical situations. The development of partial and complete right heart bypass procedures, both experimental and clinical, not only presented us with viable alternatives to aortopulmonary shunts like the Blalock-Taussig or Potts anastomosis, but it also opened the way to development of new operations such as the Fontan procedure which are based on the principle of low pressure pulmonary flow and right ventricular bypass.

Anastomosis, Surgical↗
PubMed1992

Six years' experience with closed-chest decannulation of transthoracically inserted cardiac-assist balloon catheters.

The efficiency and risks of a method that allows closed-chest decannulation of an intraoperatively inserted cardiac-assist balloon catheter are examined. The technique involves direct insertion of the balloon catheter into the ascending aorta under the protection of an indwelling silastic tourniquet. At the discretion of the surgeon, the tourniquet may be left in place or removed later through a small infrasternal incision. This method was applied for 6 years, from May 1985 to June 1991, in 18 patients. Satisfactory cardiac assistance was achieved in every patient, and no early or late complications or deaths were attributable to the technique. At the time of this report, 9 patients are still alive. The author recommends the application of the procedure whenever, in the course of open-heart operations, cardiac-assist intraaortic balloon pulsation becomes necessary and conventional transfemoral insertion is either impossible or inadvisable.

Journal Article↗
PubMed1992

Bench coronary cineangiography. A possible way to increase the number of hearts available for transplantation.

The method of "bench coronary cineangiography," that is, ex vivo contrast examination of the donor heart before implantation, is presented. The procedure appears to be most effective in detecting pathologic changes in the coronary arterial system of the explanted heart and thus would allow substantial extension of the age limits of donor hearts that may be acceptable for transplantation.

Animals↗
PubMed1991

"Half and half" woven and knitted Dacron grafts in the aortoiliac and aortofemoral positions: seven and one-half years follow-up.

One-hundred fifty-eight patients received specially manufactured aortoiliac or aortofemoral bifurcated grafts with one limb woven, the other knitted from Dacron. During an observation period ranging from 1,567 to 2,555 days (average 2,130 days) no statistically significant difference was found in either platelet adherence (30 patients studied) or in clinical patency. According to the results of the study, the type of graft (woven or knitted) did not seem to influence either platelet adherence or patency rate in the aortoiliac or aortofemoral positions.

Aged↗
PubMed1991

Apical aortic cannulation: application of an old method with new paraphernalia.

An instrument assembly consisting of a special aortic cross-clamp and double-lumen perfusion cannula is presented. The application of these instruments allows occlusion of the ascending aorta traversed by the perfusion cannula inserted directly or through the apex of the heart as well as simultaneous left ventricular venting.

Aortic Dissection↗
PubMed1991

Leonardo da Vinci and the sinuses of Valsalva.

Recent studies indicate that eddy currents generated by the sinuses of Valsalva play an important role in the physiologic closure of the aortic valve. This process is briefly discussed and evidence is presented that this fact was well known and elaborated upon by the renaissance artist Leonardo da Vinci. This fact is illustrated with his words and drawings.

Art↗
PubMed1991

Prevention of retrovirus infection after injury with contaminated instruments: an experimental study.

Owing to similarities between human immunodeficiency virus and feline retroviruses, the feline model was chosen for the study to investigate the efficacy of timely topical treatment of accidental human immunodeficiency virus infection in the operating room. Cats were subcutaneously inoculated with either feline leukemia virus or feline immunodeficiency virus. An effort was made to neutralize the virus in loco either by infiltration of the inoculation site with povidone-iodine or with monoclonal antibodies, or by cauterization and excision. The animals were periodically monitored for feline leukemia virus antigens or for feline immunodeficiency virus antibodies. The results indicated that in the feline model, the development of generalized virus infection may be prevented by local measures if applied immediately.

Animals↗
PubMed1991

Artificially induced ventricular fibrillation in the management of through-and-through penetrating wounds of the aortic arch: a case report.

Case report of a 28-year-old woman in whom a through-and-through knife injury of the aortic arch is presented. The hemorrhage could not be brought under control by conventional means and was handled by artificially induced temporary electric fibrillation of the heart, direct suture, and immediate defibrillation. The patient made an uneventful recovery.

Adult↗
PubMed1991

Long-term results after cavopulmonary anastomosis.

Brief case histories of three patients who underwent cavopulmonary anastomosis 28, 27, and 26 years ago, respectively, are presented. From this limited sample the following conclusions may be drawn. (1) Long-term survival with good functional results in patients with complex congenital anomalies who undergo cavopulmonary shunting at an early age is possible. (2) Secondary changes in the circulation of the right lung such as underperfusion of the upper lobe and the development of multiple arteriovenous connections in the lower lobe do occur, maybe more often than appreciated. (3) By 15 to 20 years after their initial operation, most of these patients require additional operations such as systemic-pulmonary artery shunt or, if possible, total repair of their underlying anomaly.

Adult↗
PubMed1990

Balloon dilatation of the stenosed aortic valve: how does it work? Why does it fail?

The hemodynamic changes that may occur in patients undergoing aortic balloon valvuloplasty were examined in the circulatory model. Four conclusions were reached. (1) Significant transvalvular pressure gradients appear only if the orifice is severely narrowed. (2) The magnitude of this gradient is highly flow dependent. (3) At critical narrowings, minute alterations in orifice size may induce most significant changes in the transvalvular gradient. (4) In low flow states significant gradients appear only if the stenosis is extreme. In patients with aortic stenosis, especially those with failing hearts and low cardiac output, the pressure gradient may be effectively decreased by minimal dilatation of the aortic orifice. These patients, however, remain in jeopardy because recurrent narrowing may cause a gradient incompatible with life.

Aortic Valve↗
PubMed1990

Can AIDS be prevented after injury with contaminated instruments?

Particulate matter comparable in size with that of human immunodeficiency virus was subcutaneously injected into experimental animals. Such matter remained at the inoculation site long enough to suggest the possibility that human immunodeficiency virus can be destroyed in loco before it invades the host's circulation. These findings may be useful in developing a method to prevent acquired immunodeficiency syndrome after accidental injury with human immunodeficiency virus-contaminated instruments.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Enhancing the applicability and effectiveness of intraaortic balloon counterpulsation.

Severe maneuvers designed to enhance the applicability and effectiveness of intraaortic balloon pulsation are presented. (1) Insertion of balloon catheter directly into the ascending aorta. The technique uses an indwelling silastic snare that allows direct insertion of a balloon catheter into the ascending aorta in the course of open heart operations without the necessity of returning the patient to the operating room and reopening the chest at the time of balloon catheter removal. (2) Elimination of electric artifacts in the course of intraaortic balloon assist. A method is presented that utilizes optical rather than electric signals to operate the intraaortic balloon pump and eliminates pacer interference as well as other electrical artifacts. (3) Enhancing assist effectiveness by balloon positioning. In a series of clinical observations, it was found that the effectiveness of balloon assist may be enhanced by as much as 75% by appropriate positioning. The previously held concept that placing the balloon in a subclavian location is optimal is challenged and it is recommended that the proper position of the balloon catheter be determined by using appropriate hemodynamic measurements in different locations. (4) Control of bleeding following removal of percutaneously inserted transfemoral balloon catheter. The technique utilizes a balloon catheter which is introduced into the puncture hole of the femoral artery after minimal surgical dissection and allows direct suturing of the bleeding source.

Artifacts↗