MMCTS
(March 29, 2007). doi:10.1510/mmcts.2006.002485
Copyright © 2007 European Association for Cardio-thoracic Surgery
Procedure
Total artificial heart-implantation technique using the CardioWest or the Thoratec system
Reiner Körfer*,
Aly El Banayosy,
Michiel Morshuis,
Gero Tenderich,
Nils Reiss and
Latif Arusoglu
Heart and Diabetes Center North Rhine-Westphalia, Department of Thoracic and Cardiovascular Surgery, Ruhr-University of Bochum, Georgstrasse 11, 32549 Bad Oeynhausen, Germany
* Corresponding author: * Tel.: +49-5731 971331; fax: +49-5731 971820. E-mail: rkoerfer{at}hdz-nrw.de
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Summary
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Total artificial heart is a safe and efficient bridge for patients with terminal congestive heart failure awaiting cardiac transplantation. The implantation of the CardioWest total artificial heart has become an accepted therapeutic option in critically ill patients who have irreversible biventricular failure and are candidates for cardiac transplantation. Because of anatomical limitations in smaller patients (women, adolescents) implantation of the CardioWest system might be impossible. In these cases we have implanted the paracorporeal Thoratec device in a modified technique as a total artificial heart.
Key Words: Cardiac retransplantation • Irreversible myocardial decompensation • Left ventricular thrombus formation • Total artificial heart
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Introduction
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The total artificial heart (TAH) orthotopically replaces both native cardiac ventricles and all cardiac valves, thus eliminating problems commonly seen in the bridge to transplantation with left ventricular and biventricular assist devices, such as right heart failure, valvular regurgitation, cardiac arrhythmias, ventricular clots, intraventricular communications, and low blood flows [1,2,3]. In our experience we consider patients with a very friable tissue or thrombus formation inside the left ventricle as candidates for the implantation of TAH (CardioWest or Thoratec TAH in smaller patients) [4]. This patient group includes patients, who suffer from chronic or acute severe rejection following heart transplantation, not responding to medical treatment and in whom recovery is not anticipated as well as patients in irreversible myocardial infarction shock and patients with the rare diagnosis of giant cell myocarditis. The timing of implantation of a TAH is crucial for the prognosis and survival of the patient.
We describe the implantation technique using the CardioWest TAH and also we report about the use of the Thoratec device as TAH with a modified implantation technique which was developed at our center.
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Surgical technique of syncardia CardioWest TAH implantation
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CardioWest TAH or Thoratec TAH devices are reliable and powerful to maintain sufficient circulation even in preexisting multiorgan failure. The devices are used in selected patients suffering from severe cardiogenic shock with a very friable myocardium. It is also successfully applied in cases of severe rejection after heart transplantation, not adequately responding to drug treatment.
To implant CardioWest TAH we use the system components which consist of left and right CardioWest ventricle, two atrial cuffs, two outflow grafts, driveline, two tools for testing of leakage (Photos 1 and 2).
The orifices of the outflow grafts and atrial cuffs are distended (Photo 3). This step will facilitate the connection.
The length of the outflow grafts should be distended in order to determine an appropriate length (Photo 4).
The atrial cuffs are trimmed 2–3 mm away from the orifice for connection. This reduces the amount of surface that can induce thrombus formation (Photo 5).
The flow Dacron outflow grafts require preclotting procedure. We prefer to seal the grafts using CoSeal Surgical Sealant (Baxter) (Photo 6). CoSeal Surgical Sealant can be sprayed on the grafts very well. With that a very nice film is formed and the grafts are sealed off (Photo 7).
The adequate length for the aorta should be between 4 and 5 cm and for the pulmonary artery between 5 and 6 cm (Photo 8).
The sternal retractor is placed in the reversed position (Photo 9). This step will offer better access to tunnel the driveline and to connect the system.
Median sternotomy and connection of the heart-lung machine. Transfer to total cardiopulmonary bypass (Photo 10).
After aortic cross-clamping, the aorta and pulmonary artery are sectioned close to the valves (Photo 11).
Both ventricles are excised at the atrioventricular level, sparing the valvular rings and a small rim of ventricle muscle behind (Photo 12).
The coronary sinus, a PFO or an atrial septal defect must be closed (Photo 13). The left atrial appendage should be closed in order to prevent any thrombus formation (Photo 14).
The trimmed atrial cuffs are sutured very carefully using a few running sutures and 4 PTFE felts for reinforcement (Photo 15). The outflow grafts are anastomosed to the aorta and pulmonary artery using a running suture (Photo 16). The anastomoses are completed (Photo 17).
It is very important to perform a check for leakage in order to prevent any surgical bleeding after the connection of the system (Photo 18).
All sutures are sealed using CoSeal Surgical Sealant (Photo 19).
The driveline tunnel is created next (Photo 20).
At first the left CardioWest ventricle is connected to the atrial cuff in an appropriate position and then to the aorta. During the connection of the system to the atrial cuff we start the de-airing by inflation of the lung. Then the outflow graft of the aorta is connected to the system in an appropriate position and with a very nice curve without any kinking or distortion. During this step it is very important to release the cross-clamping very slowly and carefully in order to continue and to complete the de-airing (Photo 21).
Then the right CardioWest ventricle is connected in the same procedure as for the left side (Photo 22). The system is connected completely. Now the system can be started and the patient can be weaned off from heart-lung machine (Photo 23).
If it is not possible to close the chest primarily due to hemodynamic problems, we close the chest temporarily using a temporary wound closure material. After a few days the chest can be closed easier (Photo 24).
The original consol, which we use in the operation room and at the first time after the implantation of the system until the patient is stabilized, is shown in Photo 25. Later on we use a small consol – EXCOR – on the ward and at home (Photo 26).
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Surgical technique of Thoratec TAH
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In order to build an atrial reservoir and to be able to connect and to anchor the apex-cannulas, we use a hemashield graft with a diameter of 38 mm and with a length of 70 mm (Photo 27).
The hemashield graft is folded in the middle (Photo 28). Both ends of the hemashield graft are cut in an oblique shape (Photo 29). The hemashield graft is cut in the middle (Photo 30). The hemashield graft is prepared as a reservoir for the left and right atrium (Photo 31).
The oblique cut surfaces of the reservoir is reinforced using a PTFE felt in order to prevent bleeding in the area of stitches. The PTFE felt is fixed using a running suture with 5.0 Prolene (Photo 32).
The original outflow graft requires a preclotting procedure. This procedure is usually time consuming and in some cases not efficacious. We prefer to cut the graft close to the stump and to perform an end-to-end anastomosis between the remaining graft and a hemashield graft with a diameter of 14 mm and with a length of 30 cm using two running sutures with two 5.0 Prolene (Photo 33).
The suture line is sealed with Fibrin glue and wrapped with a hemashield graft with a diameter of 16 mm and with a length of 15 cm. This is done in order to protect the suture and to prevent future kinking (Photo 34). The outflow hemashield graft is now ready to be used (Photo 35).
Both reservoirs are anastomosed using running sutures and the suture area is reinforced with PTFE felts (Photo 36). The outflow graft for the aorta and the pulmonary artery are anastomosed end-to-end to the vessels using a running suture (4-0) (Photo 37).
The apex cannulas (extra long with two holes) are inserted into the left and then right atrial reservoir and fixed with a silk suture (Photo 38).
After the connection and de-airing of the system, the TAH can be started and the patient can be weaned off from the heart-lung machine (Photo 39).
All grafts are covered with a surgical membrane. This step will facilitate the re-operation (Photo 40). The wound closure is performed in standard fashion (Photo 41).
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Results
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Until now 71 patients (age 15–74 years) underwent mechanical circulatory support using the CardioWest TAH. The support time ranged from 1–500 days. Underlying disease leading to circulatory support was extremely variable. Most of the patients had cardiomyopathy (33/71). Most frequent complications were long-term ventilation (51/71), renal failure (42/71) and liver insufficiency (25/71) treated by MARS.
Thirty-four percent could be successfully bridged to heart transplantation, 59% died on device and 7% are ongoing. In 14 patients (age 15–71 years) the Thoratec device was implanted as TAH. Underlying disease was cardiomyopathy in five cases, irreversible myocardial infarction shock in four patients, acute rejection in three patients, primary graft failure in one and acute myocarditis in one patient. At least four patients survived after heart transplantation, one patient died after heart transplant and eight patients died on device because of multiorgan failure, septicemia or neurological complications. One young woman died after a gynecological operation.
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References
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- Copeland JG, Smith RG, Arabia FA, Nolan PE, Sethi GK, Tsau PH, McClellan D, Slepian MJ, CardioWest Total Artificial Heart Investigators. Cardiac replacement with a total artificial heart as a bridge to transplantation. N Engl J Med 2004;351:859–867.[Abstract/Free Full Text]
- Leprince P, Bonnet N, Rama A, Leger P, Bors V, Levasseur JP, Szefner J, Vaissier E, Pavie A, Gandjbakhch I. Bridge to transplantation with the Jarvik-7 (CardioWest) total artificial heart: a single-center 15-year experience. J Heart Lung Transplant 2003;22:1296–1303.[CrossRef][Medline]
- Arabia FA. Update on the total artificial heart. J Card Surg 2001;16:222–227.[Medline]
- El-Banayosy A, Arusoglu L, Morshuis M, Kizner L, Tenderich G, Sarnowski P, Milting H, Koerfer R. CardioWest total artificial heart: Bad Oeynhausen experience. Ann Thorac Surg 2005;80:548–552.[Abstract/Free Full Text]
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Summary
Introduction
