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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
PubMed1996

[Bilateral surgical lung volume reduction in severe emphysema].

OBJECTIVE: To report preliminary results with a new surgical method of treating terminal emphysema by bilateral reduction of lung volume. PATIENTS AND METHODS: In a prospective study, the results obtained with the first 20 consecutive patients (mean FEV1: 590 +/- 180 ml) who underwent operative reduction of lung volume were recorded. 19 of the 20 patients had required continuous oxygen supply. RESULTS: The patients were extubated 8.5 +/- 6 h postoperatively; thoracic drainage was removed after 9 +/- 6 days. The degree of dyspnoea was decreased in all patients (3.5 +/- 0.5 vs 0.5 +/- 0.1). Significant reduction of overinflation occurred soon after the operation (residual volume 273 +/- 125 to 201 +/- 107% of normal; total capacity from 142 +/- 18 to 109 +/- 22% of normal), as well as reduction in the degree of obstruction (FEV1 from 18 +/- 6 to 24 +/- 7% of normal; for each, P < 0.05). One patient died 3 weeks post-operatively of Candida infection. CONCLUSION: The method looks promising for the treatment of selected patients and may thus provide an alternative to lung transplantation.

Adult↗
PubMed1996

Systemic inflammatory response syndrome after cardiac operations.

BACKGROUND: A systemic inflammatory response after open heart operation may be responsible for hyperdynamic circulatory instability and organ dysfunction. To what extent mediator release is involved needs to be clarified. METHODS: Ten patients with postoperative hyperdynamic circulatory dysregulation (group I) requiring application of alpha-constrictors and 10 patients with routine cardiac procedures and stable postoperative hemodynamic indices (group II) were analyzed for mediator release and metabolic and hemodynamic changes until the third postoperative day. RESULTS: Group I patients showed a significantly increased cardiac index and decreased systemic vascular resistance after bypass (cardiac index, group I: 5.2 +/- 1.2 L.min-1.m-2, group II: 2.5 +/- 1.6 L.min-1.m-2; systemic vascular resistance, group I: 495 +/- 204 dyne.s. cm-5, group II: 1,356 +/- 466 dyne.s.cm-5) and at 3 hours (cardiac index, group I: 4.4 +/- 0.8 L.min-1.m-2, group II: 2.9 +/- 0.6 L.min-1.m-2; systemic vascular resistance, group I: 567 +/- 211 dyne.s.cm-5, group II: 1,053 +/- 273 dyne.s.cm-5). Significantly higher serum levels of interleukin-6 were assessed in group I (postbypass, group I: 6,812 +/- 9,293 pg/mL, group II: 295 +/- 303 pg/mL; 3 hours, group I: 3,474 +/- 5,594 pg/mL, group II: 286 +/- 296 pg/mL). Concentrations of elastase, tumor necrosis factor, soluble tumor necrosis factor receptor, and interleukin-8 were elevated in group I (not significant). Early postoperative levels of soluble E-selectin and soluble intercellular adhesion molecule were also higher in group I (not significant). Continuously increased levels of endotoxin could be detected in only 3 of 10 patients in group I. Severe lactic acidosis (> or = 5 mmol/L) occurred in group I only. CONCLUSIONS: Postoperative hyperdynamic instability after open heart operations appears to be associated with a certain pattern of mediator release. In particular, interleukin-6 appears to be involved in circulatory dysregulation and metabolic derangement.

Acidosis, Lactic↗
PubMed1996

Perioperative complications in combined aortic valve replacement and extraanatomic ascending-descending bypass.

BACKGROUND: In adult patients, the combination of severe aortic valve stenosis and coarctation is rare. Surgical options comprise either a two-stage approach with valve replacement and subsequent repair of the coarctation or a one-stage repair involving valve replacement and insertion of an extraanatomic bypass graft from the ascending to the descending aorta. METHODS: We report the cases of 2 adult patients with this combined lesion who underwent simultaneous aortic valve replacement and transpericardial bypass of the coarctation. RESULTS: Weaning from extracorporeal circulation and restoration of spontaneous circulation required resuscitative measures. By increasing mean arterial perfusion pressure using norepinephrine, the observed hemodynamic instability could be controlled effectively. CONCLUSIONS: Changes in the hemodynamics of the thoracic vascular bed resulting in coronary malperfusion are discussed to be the major cause of heart failure and life-threatening ventricular arrhythmias seen in our patients after aortic valve replacement and insertion of an ascending-descending aorta bypass graft. Awareness of the complications described is considered important for successful management of these high-risk patients.

Amiodarone↗
PubMed1995

[Ectopic thyroid tissue in the heart--two case reports].

A 61-year-old previously healthy woman had been suffering from a dry cough for several weeks. On auscultation she had a 3/6 holosystolic murmur. The electrocardiogram (ECG) showed incomplete right bundle branch block (IRBBB) and abnormal repolarisation. Conventional and oesophageal echocardiography revealed a right ventricular tumour and significant coronary heart disease. At operation a tumour, arising from the interventricular septum and histologically consisting of thyroid tissue, was resected. In addition, the left mammary artery was anastomosed to the anterior interventricular branch of the left coronary artery. A 34-year-old woman developed increasing exertion-independent dyspnoea. For years she had had occasional attacks of palpitations and restlessness, once even a syncope. The ECG showed IRBBB, echocardiography demonstrated a tumour attached to the right side of the interventricular septum. The tumour was removed and found histologically to consist of colloid-containing thyroid follicles. Both tumours were benign. 45 and 36 months, respectively, later both patients are free of symptoms.

Adult↗
PubMed1995

Retransplantation of the lung. A single center experience.

While lung retransplantation remains the only therapeutic option in early or late graft failure, its value is viewed controversially. Of 134 patients undergoing pulmonary transplantation in our institution, 13 patients underwent 14 redos following heart-lung transplantation (n = 3), bilateral lung transplantation (n = 5), and unilateral lung transplantation (n = 5). Indications for retransplantation were acute graft failure (n = 2), persistent graft dysfunction (n = 3), airway complications (n = 2), and chronic graft failure (n = 7). Prior to retransplantation, six patients had been in stable respiratory failure, the remaining eight patients were on mechanical ventilation or extracorporeal membrane oxygenation (n = 2). Four patients died, 19, 43, 142, and 683 days following retransplantation due to pneumonia (n = 2), early onset of obliterative bronchiolitis (n = 1), and pulmonary embolism (n = 1). There was no correlation between mortality and intubation prior to re-operating, timing of operation, donor cytomegalovirus (CMV) status, or type of operation. Postoperative need for intensive care treatment was prolonged in patients undergoing acute retransplantation (P < 0.05). Actuarial 1- and 2-year survival rates were calculated at 77 and 64%. This was slightly lower than in the overall population following primary isolated lung transplantation (83 and 80%). Actuarial freedom from obliterative bronchiolitis (stage 3) at 1 and 2 years was calculated at 88 and 27% (primary grafts: 88% vs 72%; P < 0.05). Retransplantation is a realistic option in early and late graft failure after lung transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1995

Use of the "elephant trunk technique" in aortic surgery.

BACKGROUND: In aortic replacement, the "elephant trunk technique" uses surplus intravascular graft length to facilitate subsequent operations on the downstream aorta. This study investigates the experience with the technique since its conception by our group. METHODS: Between 1982 and 1994, 80 elephant trunks were implanted in 72 patients. In 40 cases the primary position was in the proximal descending thoracic aorta, extending an aortic arch graft. In 32 instances the elephant trunk was placed in the distal descending thoracic aorta, extending descending aortic replacement. Aortic pathology comprised aneurysms in 22 cases, chronic dissection in 47, and acute dissection in 3. Fourteen patients had Marfan's syndrome. RESULTS: There was a total of 10 early deaths, 7 of which occurred during the early experience. Subsequent downstream aortic operation was undertaken in 24 patients after a mean interval of 14 months, replacing the descending thoracic aorta in 17 cases and the thoracoabdominal portion in 7 cases. Six patients underwent third-stage procedures. Several technical modifications were developed, helping to ease placement and unfolding of the trunk. CONCLUSIONS: The elephant trunk technique greatly facilitates and at the same time reduces the risk of multiple-stage aortic replacement.

Acute Disease↗
PubMed1995

Papillary fibroelastoma of the aortic valve presenting with myocardial infarction.

We describe the case of a 56-year-old woman who presented with myocardial infarction. Noninvasive and invasive investigations revealed coronary embolism from a papillary tumor attached to the right coronary cusp of the aortic valve as the underlying process. The tumor, which histologically proved to be a papillary fibroelastoma, was excised surgically and the resulting defect in the aortic valve leaflet was closed with a patch of autologous pericardium, effectively reconstructing the aortic valve. The current literature on intracardiac papillary fibroelastoma as a source of embolism and its surgical treatment is summarized.

Aortic Valve↗
PubMed1995

Which is the best surgery for Budd-Chiari syndrome: venous decompression or liver transplantation? A single-center experience with 50 patients.

The optimal treatment of Budd-Chiari syndrome (BCS) remains an open question. It is still a matter of controversial discussion whether venous decompression or liver transplantation is superior. To elucidate the role and prognosis of both surgical options in our own experience, a consecutive series of 50 patients treated between 1981 and 1993 was retrospectively analyzed. Twelve patients had different types of portosystemic shunts or local decompressive procedures, and transplantation was performed in 43 cases, including five with previous conventional surgery. The overall mortality of 18 of 50 was conventional surgery. The overall mortality of 18 of 50 was concentrated within the early postoperative period, with no patient lost after 1 year. In the venous decompression group, the success rate was only 29%, and treatment failure was closely related to the finding of cirrhosis or technical problems like vascular thrombosis. After transplantation, early complications were rejection, primary nonfunction, or graft necrosis, and contributed significantly to the risk of sepsis. Thirty of 43 liver recipients are currently alive, including four rescued after failed decompressive surgery, with 1- and 10-year survival of 69%, and excellent recurrence-free rehabilitation. These results clearly indicate that patient selection plays a dominant prognostic role in the treatment of BCS. Venous decompression and liver transplantation should both be integrated in a common therapeutic concept, and the individual decision for the preferred approach must be based on the leading clinical symptom: portal hypertension or liver failure, together with the assessment of reversibility of hepatic damage, and the potential of cure of the underlying disease.

Adolescent↗
PubMed1994

Medical compared with surgical treatment for massive pulmonary embolism.

We compared embolectomy (when available) with thrombolysis in patients with shock and massive pulmonary embolism. 13 patients were operated on, 10 (77%) of whom survived. The inferior vena cava was routinely clipped. The 24 medically treated patients were given alteplase until systemic and pulmonary artery pressures stabilised and heparin thereafter; 16 (67%) survived. Major haemorrhage occurred in 28% of medically treated patients, but was not fatal. 1 patient had a small cerebral haemorrhage that resolved without drainage. One-fifth of the medical group had a re-embolism, which suggests that temporary caval umbrellas are indicated in medically treated patients. Thrombolysis may provide a life-saving option and a randomised trial is warranted.

Adult↗
PubMed1994

Low-dose cyclosporine therapy in triple-drug immunosuppression for heart transplant recipients.

The toxicity of long-term immunosuppressive therapy has become a major concern in long-term follow-up of heart transplant recipients. In this respect the quality of renal function is undoubtedly linked to cyclosporin A (CsA) drug levels. In cardiac transplantation, specific CsA trough levels have historically been maintained between 250 and 350 micrograms/L in many centers without direct evidence for the necessity of such high levels while using triple-drug immunosuppression. This retrospective analysis compares the incidence of acute and chronic graft rejection as well as overall mortality between groups of patients with high (250 to 350 micrograms/L) and low (150 to 250 micrograms/L) specific CsA trough levels. A total of 332 patients who underwent heart transplantation between October 1985 and October 1992 with a minimum follow-up of 30 days were included in this study (46 women and 276 men; aged, 44 +/- 12 years; mean follow-up, 1,122 +/- 777 days). Standard triple-drug immunosuppression included first-year specific CsA target trough levels of 250 to 300 micrograms/L. Patients were grouped according to their average creatinine level in the first postoperative year (group I, < 130 mumol/L, n = 234; group II, > or = 130 mumol/L, n = 98). The overall 5-year survival excluding the early 30-day mortality was 92% (group I, 216/232) and 91% (group II, 89/98) with 75% of the mortality due to chronic rejection. The rate of rejection for the entire follow-up period was similar in both groups (first year: group I, 3.2 +/- 2.6 rejection/patient/year; group II, 3.6 +/- 2.7 rejection/patient/year; p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Improvement of tracheal autograft revascularization by means of fibroblast growth factor.

Ischemic airway complications after lung transplantation remain a significant problem despite the use of bronchial omentopexy. Clinical observations suggest that enhancement of vascular ingrowth could possibly increase the efficacy of a bronchial omental flap. This study was therefore designed to investigate whether basic fibroblast growth factor can enhance blood supply of an ischemic airway by acceleration of vascular ingrowth in a rabbit autotransplant model. Segments of the trachea were harvested and transplanted into a subcutaneous pouch. The animals were randomly assigned to one of four groups: group I, no omentopexy; group II, omentopexy; group III, omentopexy and fibrin glue; or group IV, omentopexy and fibrin glue enriched with 2.5 micrograms basic fibroblast growth factor. After 14 days the animals were sacrificed. The extent of perfusion was investigated by means of radioactive microspheres. The morphology of the tracheal segments was investigated in a blinded fashion macroscopically, by means of light microscopy, and by means of scanning electron microscopy. The radioactivity measurements revealed a significantly increased perfusion of group IV (77% +/- 42%) as compared with groups I (17% +/- 13%) and III (20% +/- 16%). By macroscopic and light microscopic assessment, the epithelial integrity of group IV was significantly improved compared with groups I and II. At electron microscopy the integrity of group IV was significantly superior to all remaining groups. We conclude that a deposit of basic fibroblast growth factor and fibrin glue appears to increase revascularization of an ischemic airway from omentum and thus results in improved epithelial preservation of a tracheal autograft.

Animals↗
PubMed1994

Surgical interventions in ischemic ventricular tachyarrhythmias--endocardial resection or implanted cardioverter/defibrillator.

The surgical therapy of ventricular tachyarrhythmias (VTA) in ischemic heart disease is attracting attention, since current medical therapies are showing limited long-term efficacy. The curative concept of electrophysiologically guided endocardial resection (ER) and palliation with the implantable cardioverter/defibrillator (ICD) are compared retrospectively. From 1980-1992, 121 patients (55 +/- 9 years, 108 males, 13 females) underwent ER and 203 patients (59 +/- 9 years, 195 males, 8 females) received an ICD for ischemic VTA. Concomitant coronary revascularization was performed in 38/121 patients with ER (31%) and in 62/203 patients (31%) with ICD. Perioperative mortality was 8% (10/121 patients) for ER and 5% (10/203 patients) for ICD (P = n.s.). Hundred eleven patients with ER (mean follow-up 41 +/- 37 months) and 193 with ICD (mean follow-up 22 +/- 20 months) were available for survival analysis: freedom from sudden death was comparable for the two groups at 1 year (99% for ICD, and 94% for ER) and at 5 years (90% for ICD and 90% for ER) (P = n.s.). Freedom from cardiac death also showed no differences between the groups at 1 year (94% for ICD, and 84% for ER) and at 5 years (74% for ICD and 74% for ER) (P = n.s.). Left ventricular function, indicated by left ventricular ejection fraction, was comparable (34 +/- 9% in ER, 30 +/- 11% with ICD) (P = n.s.) in the two groups. The linearized incidence of DC-shocks was 10.3/year in ICD patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Efficient tissue gluing in aortic dissection.

The authors' method for uniting the dissected aortic wall layers with the help of gelatine-resorcinol adhesive is described focusing on special instruments used in this conjunction.

Aortic Dissection↗
PubMed1994

Tactics and techniques of aortic arch replacement.

Operations on the nondissected and dissected aortic arch still pose challenges in terms of the need for and extent of aortic replacement. Our approaches to these lesions are described against the background of 204 operations (58 aneurysms, 54 chronic dissections, and 92 acute dissections), in terms of cerebral protection, procedural choices, and operative technique. Arch anastomoses sparing the supraaortic vessels had shorter periods of circulatory arrest (17.2 min) when compared to tubular arch replacement, with insertion of some or all of these vessels (33.7 min). Early death rates due to cerebral complications were lowest in acute dissections (3/14 fatalities, with two patients showing preoperative cerebral compromise). Based on our experience, we recommend doing subtotal or total arch replacement in aneurysms regardless of cause. Radical arch surgery should be avoided in acute dissections whenever feasible. Instead, the arch should be explored and a blood-tight distal anastomosis made, going beyond any entry tears encountered in that aortic portion.

Acute Disease↗
PubMed1994

Malperfusion of the thoracoabdominal vasculature in aortic dissection.

Ischemic damage to vital organs supplied by the thoracoabdominal aorta greatly increases the overall risk of aortic dissection. Of 320 patients operated upon for aortic dissection since 1985, 33 (10.3%) underwent operations directed at the relief of malperfusion (15/158 acute type A; 9/18 acute type B; 4/78 chronic type A; 5/66 chronic type B). Organs affected were the kidneys in 32; the bowel in 20; and the spinal cord in 1, while critical lower extremity ischemia was present in 11 patients. In total, 64 vascular areas were affected. Fenestration of the dissecting membrane with or without infrarenal grafting was the procedure performed most frequently in 25, followed by replacement of the descending or thoracoabdominal aorta in 6, and bypass grafting or direct revascularization of individual side branches in 6. Six other operations targeted at the affected organs were done. Twenty-four patients underwent one-stage operation for malperfusion; in 11, early reoperation after primary aortic repair was necessary, while 2 patients were operated electively. Ten of 33 patients died in hospital, 7 of malperfusion-induced complications. Of three late deaths, one was related to sequelae of malperfusion. We conclude that immediate diagnosis and prompt relief of malperfusion offer the best prospects for patient survival. Membrane fenestration appears to be the method of choice for treating malperfusion in most patients, and must be directed to the level of aortic and/or side branch obstruction.

Aortic Dissection↗
PubMed1994

Hydrodynamic performance of Carbomedics valves in double valve replacement.

Most patients undergoing double valve replacements have reduced myocardial capacity. However, little is known about the influence of valve sizes on myocardial energy consumption in double valve replacement. This study was designed to supply hydrodynamic data for the proper selection of sizes in double valve replacement. A mock loop system was used to measure the energy consumption of CarboMedics valves at conditions resembling rest (5 L/min) and moderate exercise (9 L/min). All combinations of aortic valves size #21 to #27 with mitral prosthesis sizes #25 to #29 were tested separately. Larger size aortic prostheses revealed remarkably less energy consumption up to size #27. Under high flow (9 L/min) this effect was more pronounced. In contrast, mitral valve prosthesis sizes #25 to #29 had similar hydrodynamic data. At low flow conditions (5 L/min) no significant benefit was found with the use of a larger mitral valve. Only a reduction of less than 10 percent of total energy consumption could be achieved with the use of a mitral valve larger than #25 at 9 L/min flow. In conclusion there is no hydrodynamic reason for using a valve larger than #25 in the mitral position for patients who exercise moderately. Continuous reduction of cardiac work can be expected with the use of the largest possible aortic prosthesis up to size #27 at rest and at moderate exercise.

Aortic Valve↗