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Biomedical subjects

J Kolff

Publications and source records attributed to J Kolff.

At least 19 recordsLinked to original sources
PubMed1996

Centrifugal pump failures.

Centrifugal pumps will not pass gross quantities of gaseous emboli due to the nonocclusive nature of the pump. However, retrograde flow can occur under circumstances that include: product malfunctions, low flows, and human errors. Negative pressure created by falling arterial perfusate can draw air into the cannula. Food and Drug Administration (FDA) records about centrifugal pump malfunctions were obtained. Out of 350,000 cases completed with centrifugal pumps over a 23 month period, the FDA received reports of 68 malfunctions, 22 electrical burning smells, and three speed surges, yielding a failure rate of 1 in 3,763 cases. FDA records revealed five death reports and three serious injury reports. A survey was sent to 2,424 Society of Thoracic Surgeons' members to obtain more information; 285 who use centrifugal pumps responded. Sixty surgeons (21%) reported 108 malfunctions, including 46 complete pump failures. Fifty-one of 243 surgeons (21%) who use centrifugal pumps for bypass reported that perfusionists have forgotten to clamp the pump line, resulting in backflow. We conclude centrifugal pumps are generally safe, but malfunctions, low flows, and human errors can lead to retrograde flow and occasionally air embolization. There are valves that can be added to the bypass circuitry to prevent this risk.

Cardiopulmonary Bypass↗
PubMed1995

Physician understanding of the National Practitioner Data Bank.

National Practitioner Data Bank (NPDB) reports are part of the process for acquiring staff privileges, professional credentials, and licenses throughout a physician's entire career. We surveyed our hospital's 66 residents to assess their understanding of NPDB. Only 9 residents had heard about NPDB. A follow-up survey of the 10 medical schools in Pennsylvania and Maryland showed just 4 schools covered NPDB in their curricula. Finally, we did a third survey--of 1,410 Pennsylvania Medical Society members. Eighty-one percent did not know that denial of initial license application was not a reportable offense; 69% did not know that voluntary entrance into alcohol/drug rehabilitation was not reportable; and 75% did not know that denial of expanded privileges because of level of clinical competence was reportable. Only 13% knew how to obtain their files. Our surveys suggest physicians have a poor understanding of NPDB even though these reports could have career-jeopardizing implications, especially if the Clinton administration expands access to NPDB.

Adult↗
PubMed1994

New technique for coronary sinus cannulation using a fiberoptic stylet.

Fluoroscopy, echocardiography, blind digital approach, and direct visual insertion have been used for retrograde cannulation of the coronary sinus. We cannulate the coronary sinus by transillumination using a standard flexible retroplegia cannula with a reusable fiberoptic stylet designed by our open heart program. An attachable light source illuminates the tip, which is guided into the coronary sinus ostium. We have used the technique in 16 patients who could not be cannulated with the blind digital method.

Catheterization↗
PubMed1993

Management of patent saphenous vein grafts during reoperative coronary artery bypass grafting.

A patient was referred for coronary artery bypass reoperation. After a left internal mammary artery was grafted to the left anterior descending coronary artery, the diseased but patent old saphenous vein graft was ligated. This resulted in severe myocardial failure, which was corrected only after restoration of flow through the old vein graft. We suggest the decision to ligate or replace an old vein graft should be individualized to avoid the risk of myocardial ischemia.

Cardiac Output, Low↗
PubMed1992

New approaches for cardiac assists: "back to the future".

The treatment of the modern epidemic of coronary artery disease requires the availability of various cardiac assist devices. A review and future implications of the use of retrograde coronary venous perfusion, the intraaortic balloon, a new ascending aortic pump, variable atrial septal defect, and novel energy sources are discussed.

Aged↗
PubMed1990

Endomyocardial biopsy: variations in venous access for endomyocardial biopsy in cardiac transplantation.

With the increasing number of cardiac transplantation procedures performed worldwide, a strategy for endomyocardial biopsy techniques has evolved at our institution. Specific approaches for venous access for biopsy purposes are described. These include approaches via the right internal jugular vein, right external jugular vein, left subclavian vein, and the femoral veins. Particular emphasis is placed on the technical nuances of each approach. In approximately 2,000 endomyocardial biopsies performed on 155 transplant patients from 1984-1989, only two major complications occurred, only one of which required operative intervention. This was a perforated right ventricle, and the patient recovered after repair without further sequelae. No pneumothoraces or infection occurred during this time period. With proper understanding of regional anatomy, fluoroscopic appearance, and experience, endomyocardial biopsies can be performed with an extremely low incidence of major or minor complications.

Biopsy↗
PubMed1988

Development of the Philadelphia Heart System.

A new pneumatic artificial heart system has been developed. The design criteria have been to produce an integrated series of blood pumps and drive systems that would reduce blood trauma and reactivity, while incorporating industrial, mass-production techniques. The system attempts to reproduce the natural heart's pressure and flow waveforms and allows the prosthetic valves to be installed in a manner consistent with their design. The system's ventricles are constructed entirely of polyurethane by a combination of vacuum-forming and solution-casting techniques. The atrial cuffs and arterial grafts are permanently attached to the pumps and do not incorporate a quick connect system. The prosthetic valves are sewn into the inflow and outflow tracts using their clinical sewing rings. Besides eliminating the crevices normally found in quick connect systems, this method mounts the valves in an extremely compliant housing to increase shock absorption. The drive system produces a systolic air flow with a variable pressure rise (dP/dt) to reduce mitral valve closing velocity. This system has been implanted into 25 calves to date, of which 17 were chronic experiments. In 14 animals, St. Jude bileaflet valves were used and these animals had a mean survival of 39 days. Six of these animals survived over 30 days, with the longest being 129 days. All of the animals showed the characteristic postoperative drop in red blood cell count and hematocrit that returned to near preoperative values in about 3 weeks. The plasma free hemoglobin values generally remained below 5 mg/dl. The necropsies performed on several of the earlier animals revealed renal infarcts. However, in two of the later experiments, no kidney damage was found. The blood contacting surfaces of the atrial cuffs from the animals surviving over 100 days were covered with a fibroproliferative pseudoneointimal growth that extended from the sewing rings to the natural atrial tissue. Grossly, this appears to be the same type of tissue response seen when only a valve is implanted in a natural calf heart.

Animals↗
PubMed1988

Sternotomy closure with Parham bands.

The closure of a median sternotomy incision requires secure bony approximation to prevent postoperative pain, sternal click, and/or nonunion of bone. The standard technique of sternotomy closure involves the use of stainless steel wires for reapproximation of the sternum. These wires occasionally break or pull through bone, resulting in instability of either a portion of the sternum or the entire sternum. Presented here is our technique for sternotomy closure that provides secure closure with reduced postoperative morbidity.

Bone Wires↗
PubMed1986

Complement activation during cardiopulmonary bypass. Comparison of bubble and membrane oxygenators.

A prospective randomized trial involving 91 patients undergoing cardiopulmonary bypass compared the effects of bubble oxygenators (with and without methylprednisolone sodium succinate) and membrane oxygenators on complement activation and transpulmonary sequestration of leukocytes. Patients were divided as follows: Group I, 30 patients, bubble oxygenator; Group II, 31 patients, bubble oxygenator and methylprednisolone sodium succinate (30 mg/kg); Group III, 30 patients, membrane oxygenator. In Group I, C3a increased from 323 +/- 171 ng/ml during cardiopulmonary bypass to 1,564 +/- 785 ng/ml at 25 minutes after bypass (p less than 0.0001). A significant decrease in C3a was found in Groups II and III compared to Group I (p less than 0.0001). C5a did not change significantly during cardiopulmonary bypass in any group. Reestablishment of pulmonary circulation at the end of bypass produced significant transpulmonary leukocyte sequestration in Group I; the median cell difference was 1,700/microliter. Transpulmonary sequestration was significantly (p less than 0.0001) less in Group II (median cell difference = 200/microliter) and in Group III (median cell difference = 400/microliter) than in Group I. We conclude that cardiopulmonary bypass with a bubble oxygenator alone initiates significantly (p less than 0.0001) more C3a activation and leukocyte sequestration than when methylprednisolone sodium succinate (30 mg/kg) is given 20 minutes before the start of cardiopulmonary bypass with a bubble oxygenator or when a silicone membrane oxygenator is used.

Adrenal Cortex Hormones↗
PubMed1985

Artificial heart and left ventricular assist devices.

We believe there will be a place in cardiac surgery for a variety of assist and replacement devices. The extracorporeal assist devices, with or without extracorporeal membrane oxygenation, will be needed for acute situations requiring time for diagnosis and prognosis to be determined. There will also be a place for intrathoracic paraventricular assist devices that may temporarily or permanently support the right or left ventricle. Finally, we believe that there will be a number of patients whose native cardiac function is of no help at all and whose hearts probably should be removed to make room for an improved blood pump of human design. Pneumatic ventricles are presently available and we should see increasing use of them over the next couple of years. The convenience for a patient of electrical wires instead of pneumatic hoses coming out of the chest is obvious. However, the complexity and cost of the overall system is considerably greater, further testing and development is needed. Dr. William Pierce already has kept an animal alive for over 6 months with an electrically driven heart. Clearly, the electrically driven systems are the pumps for the next decade.

Assisted Circulation↗