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Biomedical subjects

H G Borst

Publications and source records attributed to H G Borst.

At least 19 recordsLinked to original sources
PubMed1992

Predictive criteria for the need of extracorporeal circulation in single-lung transplantation.

Use of extracorporeal circulation is mandatory in heart-lung and en bloc double-lung transplantation. However, no criteria exist to predict the necessity of its application during single-lung transplantation for parenchymal lung diseases. We therefore reviewed our experience in 23 patients undergoing single-lung transplantation for idiopathic pulmonary fibrosis. All patients were evaluated by preoperative right heart catheterization. For intraoperative monitoring, a pulmonary artery thermodilution catheter was placed in the contralateral lung to repeatedly assess pulmonary artery pressure, cardiac output, and pulmonary vascular resistance. Extracorporeal circulation was necessary during graft implantation in 4 patients, whereas 19 patients underwent operation without it. Preoperative demographic patient data, time of ischemia, and hemodynamic values obtained preoperatively and before the clamping of the pulmonary artery showed no significant differences between groups. In contrast, after the clamping of the pulmonary artery, a significant drop in cardiac index of about 1.5 L.min-1.m-2 (p less than 0.01) and a concomitant rise in pulmonary vascular resistance (p less than 0.01) was observed in the group requiring extracorporeal circulation, whereas these variables showed no significant changes in the other 19 patients. Pulmonary artery pressure rose significantly in both groups (p less than 0.05), without significant differences between them. It is concluded that intraoperative assessment of cardiac index and pulmonary vascular resistance is essential for estimation of cardiac performance during single-lung transplantation. A decrease in cardiac index of more than 1.5 L.min-1.m-2 after the clamping of the pulmonary artery rather than the degree of pulmonary hypertension is indicative of the need of extracorporeal circulation.

Adult↗
PubMed1992

Advances in aortic arch surgery.

From 1980 to January 1991, 130 patients (89 men and 41 women, aged 22 to 76 years; mean age, 52 years) underwent 133 interventions on the aortic arch. Aneurysm was diagnosed in 57 patients, whereas 29 had chronic and 44 acute aortic dissection. In 67 instances a partial and in 35 instances a total arch replacement was performed. The distal arch was approached through a left thoracotomy in 14 patients. Local interventions (n = 17) included surgical reconstruction and glue procedures. Additionally, 55 patients required aortic valve replacement, preferably with composite grafts (n = 46), whereas the valve was reconstructed in 14. Procedures were performed using hypothermia (nasopharyngeal temperature, 11 degrees to 25 degrees C) and circulatory arrest (mean time, 27 minutes). Early mortality was 13.9% at the first operation on the aortic arch. Early deaths included 7 of 57 patients with aortic aneurysm (12.3%), 2 of 29 patients with chronic dissection (6.9%), and 9 of 44 patients with acute dissection (20.5%). Neurological (n = 6) and cardiac events (n = 5) were the most common causes of early death. Since 1987, 7 of 88 patients have died for an overall mortality of 8.0%. With growing experience, proper indication, and adequate operative strategy including the use of circulatory arrest in hypothermia, operation on the aortic arch can be performed with an acceptable risk.

Adult↗
PubMed1992

Decreased incidence of bronchial complications following lung transplantation.

Despite omental wrap and avoidance of prophylactic administration of corticosteroids in the early postoperative phase, ischemic bronchial complications still represent an important source of early morbidity and mortality following lung transplantation. In a retrospective analysis, the effect of pharmacological enhancement of pulmonary collateral flow on bronchial healing was investigated. Thirty-nine consecutive unilateral or bilateral transplant procedures (Tx) were analyzed. Immunosuppression consisted of rabbit antithymocyte globulin (RATG), cyclosporine A, and azathioprine. In group 1 (10 Tx, 12 anastomoses) routine immunosuppression was employed and the anastomoses wrapped with an omental or pericardial pedicle. In group 2 (29 Tx, 41 anastomoses) PGI2 (4 ng/kg per min x 48 h), heparin (200 U/kg per day), and prednisolone (0.5 mg/kg per day) were added to the therapeutic regimen. The 2 groups were comparable with respect to age and sex of the patients, primary diagnosis, type of transplant, intraoperative use of extracorporeal circulation, graft ischemia, duration of mechanical ventilation, and mortality. Bronchoscopic evidence of a significant bronchial ischemia (extending more than 1 cartilaginous ring beyond the anastomosis) was seen in 8 of 12 anastomoses in group 1 vs 14 of 53 anastomoses in group 2 (P = NS). In group 1, significant bronchial stenosis required implantation of an endobronchial silicone stent in 6 of 12 anastomoses, whereas in group 2, no significant bronchial stenosis occurred (P less than 0.01). No negative effects possibly related to the prophylactic administration of corticosteroids could be observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Artificial intravascular oxygenation (IVOX). Application to the treatment of postoperative respiratory failure].

Very recently, the concept of artificial intracorporeal oxygenation of blood for patients suffering from respiratory failure has been introduced into clinical practice through development of a totally implantable intravascular oxygenator (IVOX). We report on the use of such a device in a patient who developed severe respiratory insufficiency secondary to prolonged hypovolaemic shock and pneumonia following successful repair of a ruptured abdominal aortic aneurysm in September, 1990. Postoperatively, severe hypoxaemia occurred (AaDO2 548-602 torr) despite extensive mechanical ventilatory support. There was no obvious chance to overcome this situation by conventional therapeutic measures and the decision was made to institute IVOX therapy. Hypoxaemia was resolved immediately and both FiO2 and tidal volume could be reduced within hours. The patient's respiratory condition continued to improve over the next days leading to termination of IVOX therapy after 71 hours. However, the necessity of long-term ventilatory support secondary to recurrent pneumonia and sepsis, multiple abdominal reoperations for ischemic colitis and retroperitoneal abscess prolonged his recovery. He was discharged from the hospital after four months and is alive and well now 14 months after his operation. He is the first long-term survivor after IVOX therapy in Europe. IVOX may be successfully used in selected patients while the indications and it's potential role in the therapy of severe respiratory failure still need to be defined.

Humans↗
PubMed1992

Open-heart surgery in patients requiring chronic hemodialysis.

The management and outcome of open-heart surgery in 31 patients requiring chronic hemodialysis because of end-stage renal failure are reviewed. The reasons for surgery were coronary artery disease (20 cases), mitral valvulopathy (5, including 3 with tricuspid insufficiency), aortic valvulopathy (5, including 2 with coronary artery disease) and perforation of an aortic aneurysm into the left upper lung lobe. Surgery was elective in all but the last case. Apart from double venous cannulation to avoid potassium overload after cardioplegia, and hemofiltration in the extracorporeal circulation permitting removal of 1,500-2,000 ml fluid during bypass, procedure was routine. Postoperatively fluids were restricted and serum potassium levels were not allowed to exceed the known preoperative maximum. Four patients required catecholamine support for 3-10 hours. Thirty were weaned from the respirator after 8-41 (mean 16) hours. The one perioperative death was due to complications associated with post-bypass administration of protamine. Dialysis was restarted 20-69 (mean 32) hours postoperatively. With appropriate management of fluid balance and potassium, open-heart surgery in dialysis-dependent patients need not carry heightened risk.

Adult↗
PubMed1992

[Lung transplantation].

In the past 10 years, three different types of lung transplantation were introduced into clinical practice, the combined transplantation of the heart and both lungs (HLTx), unilateral single lung transplantation (SLTx), and bilateral sequential lung transplantation (DLTx). At present, the indications for the various procedures have not been ultimately defined. Through 1991, a total of about 1,100 HLTx, 460 SLTx, and 160 DLTx was performed worldwide. One- und 3-year survival rates amount to 75-60% resp. in HLTx, to 80-70% resp. in SLTx, and to 70-60% resp. in DLTx. In our own experience with 24 HLTx, 32 SLTx, and 18 DLTx patients, global survival rates at one and 3 years are 85 and 80%, resp. The vast majority of surviving patients is able to lead a near normal life both physically and socially.

Actuarial Analysis↗
PubMed1992

[Sources and developments in heart surgery].

This contribution deals with the development of the individual ramifications of cardiac surgery from their inception to the presence and especially highlights the personalities responsible for these breakthroughs. The trials and errors of these developments are described along with the multitude of presently unanswered questions including those related to thoracic organ transplantation, cardiac assistance, and replacement as well as the socio-economical aspects of modern cardiac surgery.

Cardiac Surgical Procedures↗
PubMed1992

[Surgical aspects of acute aortic dissection].

This paper highlights some of the surgical aspects of acute aortic dissections such as: emergency diagnosis, indications for surgery, reconstructive operative techniques, malperfusion phenomena and necessity for follow-up. Aortic dissection is caused by an intimal tear, called the "entry", and subsequent splitting of the media by the stream of blood. Two lumina are thus created, which may communicate through "re-entries". As this creates severe weakness of the aortic wall, rupture and/or dilatation are the imminent dangers of acute aortic dissection. Acute aortic dissection type A, by definition involving the ascending aorta (Figures 1 and 2), is an absolute indication for emergency surgical treatment, because its natural history shows an extremely poor outcome (Figure 3). Due to impending (intrapericardial) aortic rupture, it may be necessary to limit diagnostic procedures to a minimum. Transesophageal echocardiography is the method of choice for establishing a quick, precise and reliable diagnosis (Figure 4). In stable patients, computed tomography gives additional information about aortic diameters or sites of extrapericardial perforation. Digital subtraction angiography (DSA) shows perfusion of the lumina and dependent organs. The surgical strategy in acute aortic dissection type A aims at replacement of the ascending aorta. Reconstructive techniques have to be considered, especially in aortic valve regurgitation without annuloectasia (Figures 5 and 6). In recent times, the use of GRF tissue glue has reduced the need for teflon felt. Involvement of the aortic arch should be treated aggressively up to the point of total arch replacement in deep hypothermic circulatory arrest as part of the primary procedure (Figure 7). Malperfusion phenomena of aortic branches remain risk-factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1992

Long-term follow-up after separate replacement of the aortic valve and ascending aorta.

Between May 1974 and November 1991, 28 patients underwent a separate replacement of the aortic valve and the ascending aorta (20 male, eight female; 32 to 71 years old, x = 52 years). 23 patients were operated for ascending aortic aneurysm, three for chronic and two for acute aortic dissection type A. 17/18 patients living at the beginning of this study were re-investigated after a mean follow-up interval of 8.5 years postoperatively with DSA, thoraco-abdominal CT and echocardiography. 1/8 biological aortic valves and 1/20 mechanical valves had to be replaced (four years and two months postoperatively) for valve degeneration and paravalvular leakage respectively. Three patients developed a sinus of Valsalva aneurysm and were reoperated five, 9.2 and 9.3 years after primary repair. In all three patients histological signs of idiopathic degenerative media disease of the aorta were found. Two other patients presented with a perfused perigraft channel and therefore had to be reoperated. Patients with chronic aortic dissection type A and/or ascending aortic aneurysms presenting clinical or intraoperative signs of degenerative media disease of the aorta should undergo composite graft replacement to preclude formation of sinus Valsalva aneurysms.

Adult↗
PubMed1992

[Progress in surgery of the aortic arch].

We summarize our experience out of 133 operations involving the aortic arch which were performed in 130 patients throughout the last 13 years. Aortic pathology was aneurysmal disease in 57 cases, acute aortic dissection in 44, and chronic aortic dissection in 29 patients. Operative strategies included partial replacement or repair of the aortic arch in 80 cases and subtotal or total replacement of the transverse arch in 53 patients. In 19 cases presenting with aneurysms of the descending thoracic aorta, implantation of an elephant trunk prothesis was performed simultaneously. The operations were performed during circulatory arrest (10-64 min, mean: 27 min) and in deep hypothermia (nasopharyngeal temperature: 11-25 degrees C). Recently, two modifications of the technique were introduced: First, the site of arterial inflow cannulation is changed by intubating the prothesis directly during reperfusion providing antegrade perfusion. Second, in patients with acute aortic dissection, the false lumen of the aortic root and arch is filled with resorcinformol glue and the layers are readapted by this means after anatomical reconstruction. Overall, early mortality was 14.3% and was much higher in acute dissection (22.7%) when compared to chronic dissection (6.9%, p = 0.110). A total of 24 reoperations were necessary in 16 patients of this group with subsequent replacement of the descending thoracic aorta being most frequently performed (n = 14). Actuarial survival after 5 years was not significantly different between the groups (69.1%) but showed a progressive decline for patients with aneurysms and chronic dissection (11 late deaths) while no late deaths occurred in acute dissections.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Future horizons of lung preservation by application of a platelet-activating factor antagonist compared with current clinical standards. Euro-Collins flush perfusion versus donor core cooling.

With the introduction of platelet-activating factor antagonists, a direct inhibition of ischemia-induced reperfusion injury can be achieved by prevention of platelet activation, reduction of microvascular leakage, and platelet-activating factor-induced bronchoconstriction. At present, two preservation methods are established for clinical lung preservation: (1) donor core cooling by extracorporeal circulation and (2) pulmonary artery flush with Euro-Collins solution and prostacyclin. We compared the quality of organ preservation obtained with these methods to the application of a platelet-activating factor antagonist (WEB 2170; 0.3 mg/kg) for the donor, perfusion solution, and throughout the first 6 hours of reperfusion in combination with prostacyclin (20 ng/kg/min) and Euro-Collins solution (60 ml/kg). Eighteen heterotopic heart and orthotopic left lung transplants were performed in three groups of six dogs each after 6 hours of cold ischemia (group I, donor core cooling; group II, Euro-Collins flush and prostacyclin; group III, Euro-Collins flush, prostacyclin, and WEB 2170). Myocardial preservation was achieved with St. Thomas' Hospital solution (20 ml/kg) in all groups. After transplantation, cardiorespiratory function was assessed at an inspired oxygen fraction of 0.4. After transplantation, superior results were observed in group III, as expressed by significantly improved oxygenation, while cardiac output and pulmonary artery pressures were similar in all groups. We concluded that the use of the platelet-activating factor antagonist WEB 2170 resulted in better lung preservation than current clinical standards.

Animals↗
PubMed1991

Fulminant pulmonary embolism: symptoms, diagnostics, operative technique, and results.

Fulminant pulmonary embolism associated with cardiac arrest has an extremely high mortality. The feasibility of pulmonary embolectomy initiated during resuscitation is still under discussion. Between January 1975 and January 1991, pulmonary embolectomy was performed in 27 patients, 21 to 79 years old. The diagnosis was established primarily by clinical findings in 18 patients, by angiography and ventilation-perfusion mismatch in 4 patients, and by transesophageal echocardiography in 1 patient seen recently. Eleven patients did not require resuscitation (group 1); 5 patients had to be resuscitated and underwent operation after circulation was reestablished without need of further cardiac massage (group 2); and 11 patients were connected to extracorporeal circulation devices during cardiopulmonary resuscitation (30 to 210 minutes) (group 3). Embolectomy was performed using extracorporeal circulation with the heart beating (n = 2) or fibrillating (n = 15) or using cardioplegia (n = 10). Fifteen patients received a caval clip or ligature at the end of the procedure. Twelve patients died early postoperatively; the mortality rates were 36%, 60%, and 45% for groups 1, 2, and 3, respectively. Eight patients died of right heart failure, and 2 patients each died of brain death and sepsis. Of the surviving patients, only 1 showed ischemic brain damage. Mean stay in the intensive care unit was 5.1, 7.0, and 9.75 days for groups 1, 2, and 3, respectively. There were no recurrent embolisms during the 15-year follow-up (mean follow-up, 4.6 years). This experience demonstrates that even with subtotal obstruction of the pulmonary arteries, effective cardiopulmonary resuscitation with maintenance of uncompromised brain function is possible.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiopulmonary Resuscitation↗
PubMed1991

Extracorporeal membrane oxygenation as a bridge to lung transplantation.

The occurrence of severe graft failure after lung transplantation which appears refractory to conventional treatment represents a difficult situation with regard to the therapeutic strategies available. Of 17 patients undergoing single lung transplantation at our center, 2 developed early graft failure. In both, temporary artificial cardiopulmonary support by means of extracorporeal membrane oxygenation became necessary as a bridge to retransplantation. Both patients were successfully retransplanted after 8 h and 232 h, respectively, of extra-corporeal support. Postoperatively, there was a variety of complications. The first patient completely recovered from temporary severe cerebral dysfunction diagnosed as "locked-in syndrome". She was discharged from hospital on the 93rd postoperative day and remains alive and well 10 months after her operation. The other patient recovered well early after retransplantation. Later, however, airway problems developed, requiring the implantation of endotracheal stents. Cachexia and several episodes of viral pneumonia contributed to the progressive deterioration of her clinical status. She finally died after being hospitalized for 5 months after the original operation. These two cases illustrate the feasibility of using extracorporeal membrane oxygenation as a bridge to pulmonary transplantation.

Adult↗
PubMed1991

Tumor-related obstruction of the inferior vena cava extending into the right heart--a plea for surgery in deep hypothermic circulatory arrest.

This study reviews eight patients, 39-63 years old, with tumor-related obstruction of the inferior vena cava (IVC) extending into the right atrium (n = 5) and ventricle (n = 3). Five patients suffered from renal cell carcinoma, 3 from sarcomatous disease. The general approach was a median sternotomy and laparotomy with hypothermic circulatory arrest (17.0-20.5 degrees C; 23-46 min) in six patients, while in two patients, the IVC was clamped sequentially under moderate hypothermia and extracorporeal circulation. Four patients had tumor infiltration of the IVC necessitating partial caval resection. In three, the IVC was reconstructed by fabric patches or tubular prothesis. In one patient, the continuity of the IVC was interrupted permanently. Three patients underwent nephrectomy during the same procedure, two before and one after IVC disobliteration. In one patient each, pulmonary embolectomy and intrahepatic IVC stenting were performed. Two patients died early, one due to uncontrollable hemorrhage the other due to non-cardiogenic pulmonary edema. Six patients were discharged in good physical condition and are still alive at a mean follow-up of 24 months. Five patients have since remained free of recurrence, one patient underwent three further surgical interventions for bone metastases. We feel that IVC desobliteration is feasible in selected cases with extended tumor-related obstruction with an acceptable early risk and late outcome.

Adult↗
PubMed1991

Hyperacute rejection in heart allografts. Case studies.

Hyperacute rejection in orthotopic heart allografts is a rare event. In our material from a total collective of 524 heart-transplanted patients, we have observed two cases of hyperacute rejection, which are presented in this case report. Histopathologically, this entity is characterized above all by the following triad: pronounced edema, hemorrhages, and regressive changes up to necroses of myocytes. Besides the well-known risk factors, our report draws attention to two further factors possibly associated with an increased risk of hyperacute rejection: 1) repeated cardiac surgery prior to the transplantation, and 2) presence of identical viral genomes in recipient's and donor's heart.

Adult↗
PubMed1991

Extracorporeal membrane oxygenation (ECMO): extended indications for artificial support of both heart and lungs.

Extracorporeal membrane oxygenation (ECMO) was used to achieve temporary artificial support in cardiac and pulmonary function in 22 patients from 1987 to September 1990. Standard indications were postcardiotomy cardiogenic shock (n = 4), neonatal (n = 1) and adult respiratory distress syndrome (n = 4). ECMO was also used for extended indications, such as graft failure following heart (n = 11) or lung transplantation (n = 2). In six of these cases ECMO was instituted as a bridge device to subsequent retransplantation of either the heart (n = 4) or one lung (n = 2). One out of nine patients supported by ECMO for standard indications, and two out of 13 patients supported for extended indications are long-term survivors. This series illustrates the results with ECMO in emergency situations, in patients under immunosuppressive protocols, or in patients with advanced lung failure requiring almost complete artificial gas exchange. In such complex situations, ECMO does provide stabilization until additional therapeutic measures are in effect. ECMO cannot be recommended for postoperative cardiogenic shock but short-term ECMO support is an accepted method in most cases with graft failure or pulmonary failure or other origin.

Adult↗