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Biomedical subjects

H Dalichau

Publications and source records attributed to H Dalichau.

At least 73 records · Page 4Linked to original sources

Heart transplantation in patients with diabetic end-organ damage before transplantation.

Diabetes mellitus with preexisting end-organ damage (EOD) is considered a contraindication for heart transplantation. The outcome of such patients has not been well characterized. Among 138 patients transplanted between 12/88 and 7/94, 29 were diabetic (11 insulin-dependent); of these, 12 had preexisting EOD, defined as a creatinine clearance < or = 50 ml/min, a 24-hour urine protein concentration > or = 500 mg/L or typical symptoms of peripheral or autonomic polyneuropathy, and 17 had no EOD. We compared diabetics with and without EOD and non-diabetics (n = 109) for operative mortality, length of stay, serum creatinine, fasting glucose levels, and postoperative prednisone doses at 1,6, and 12 months. Actuarial survival and freedom from rejection and infection were analyzed. Both diabetic groups were significantly older than nondiabetics, Ischemic time, operative mortality, surgical technique, ICU- and total length of stay were similar. Actuarial survival and freedom from rejection were similar among the three groups. Infection rates including CMV did not differ. Serum creatinine levels increased in all groups compared to pretransplant levels (p = 0.001), but without significant differences among the groups. Post-transplant glucose levels at 6 and 12 months were higher for diabetic patients with EOD than for those without or for nondiabetics (183, 153, and 94 mg/dl at 6 months, p = 0.01; 202, 161, and 102 mg/dl at 12 months, p = 0.0001). Prednisone dosage was lower in diabetics with EOD at 6 months, but did not differ among the three groups at 12 months. The incidence of angiographically proven transplant vasculopathy did not differ at 1 and 2 years. Diabetics with preexisting EOD undergoing heart transplantation experience similar short- and intermediate-term results when compared to diabetics without EOD and nondiabetics. Metabolic control is more difficult to achieve, as indicated by higher fasting glucose levels. Larger and longer-term prospective studies have to confirm our findings, since the shortage of donor organs would increase if such patients were transplanted routinely.

Actuarial Analysis↗

[New treatment methods in heart valve surgery--the Toronto SPV stentless bioprosthesis].

Stentless valves may be an alternative to conventional stented bioprostheses and homografts. From all tissue valves homografts proved to have the best long term results. But homografts are not always available. Stentless bioprostheses are similar to homografts concerning in implantation technique, valve anatomy and physiologic function. The stentless design leads to remodeling of the left ventricle and the aortic root, resulting in a superior hemodynamic profile. Nevertheless long term results are required.

Adult↗

One-stage surgery of coronary arteries and abdominal aorta in patients with impaired left ventricular function.

BACKGROUND: Coronary artery disease (CAD) is common in patients with abdominal aortic aneurysms (AAA). Some patients will present with the combination of unstable angina, impaired left ventricular function, and a large symptomatic (ie, leaking, expanding) AAA. In this subgroup of high-risk patients, aortic cross-clamping may have a deleterious effect on cardiac function, whereas coronary artery bypass graft surgery before aneurysmectomy (staged operation) carries the risk of perioperative aneurysm rupture. One-stage surgery, ie, myocardial revascularization and simultaneous aortic aneurysm repair, has been proposed in this situation. This article summarizes our results with the combined one-stage approach in patients with symptomatic CAD, impaired left ventricular function, and large symptomatic aortic aneurysms or severe aortic occlusive disease. As yet, this cohort is the largest reported in the English literature. METHODS AND RESULTS: In 25 patients (24 men) with a mean age of 69.4 years (range, 55 to 80 years), we performed combined open heart and intra-abdominal aortic surgery. Eighteen patients had severe three-vessel disease and impaired left ventricular function (ejection fraction, < 35%). In addition, 3 of these patients had severe aortic valvular stenosis and/or insufficiency. Seven patients had one- or two-vessel disease with a low left ventricular ejection fraction in the range of 15% to 30%. All patients were in New York Heart Association functional class III or IV. Twenty-one of 25 patients had symptomatic infrarenal AAA (perianeurysm hematoma was present in 9 patients, and 12 patients had signs of beginning perforation). Four patients with aortoiliac occlusive disease and limb ischemia were simultaneously operated on. The surgical procedure started with the performance of coronary artery bypass graft surgery. After completion of myocardial revascularization, aortic aneurysm repair was performed while extracorporeal circulation was continued for mechanical cardiac assist until aortic surgery was fully accomplished. An average of 3.3 (3 to 5) coronary bypass grafts were placed, including 17 internal thoracic artery grafts. In addition, three aortic valves were replaced. In the abdominal aortic position, 12 straight tube grafts and 13 bifurcation grafts were implanted, and three renal and two carotid arteries were simultaneously repaired. The total time of surgery varied from 2.3 to 8.5 hours, with a mean time of 3.9 +/- 1.4 hours. One intraoperative myocardial infarction occurred despite open grafts. Intensive care unit treatment lasted 1 to 13 days, with a mean of 3.6 +/- 2.5 days. Three patients (12%) died after surgery--1 because of acute renal failure induced by an adverse reaction to heparin, 1 because of myocardial infarction, and 1 because of multiorgan failure. One-year actuarial survival rate was 88%, which compares favorably with survival after isolated AAA surgery in this high-risk patient subgroup and equals survival in patients with severe CAD and severely depressed myocardial function. CONCLUSIONS: One-stage surgery is a possible approach to highly symptomatic patients with severe multivascular disease and has acceptable early morbidity and mortality. Patients with severely impaired left ventricular function and unstable CAD carry a high risk of left heart failure and/or myocardial infarction during abdominal aortic surgery. Extracorporeal circulation protects the heart from the hemodynamic changes after aortic clamping or declamping during abdominal aortic surgery. The present study demonstrates that one-stage procedure is a reasonable option for this patient subgroup.

Aged↗

True aneurysm of the superior gluteal artery: case report and review of the literature.

Aneurysms of the gluteal arteries are rare and mostly are caused by pelvic fractures or penetrating injuries. As such these aneurysms are pseudoaneurysms. As an absolute rarity we report the case of a 43-year-old man with a histologically verified 5 cm-diameter, true saccular aneurysm of the left superior gluteal artery. The patient was admitted with 6-weeks ongoing sciatic pain without previous trauma. He was scheduled for surgery because an initial attempt of transcatheter embolization failed. By dividing the origin of the gluteus maximus muscle from the iliac crest, the aneurysm was exposed at the pelvic outlet by an extrapelvic approach and was excluded by endoaneurysmorrhaphy. Uncontrolled bleeding was prevented by temporary occlusion of the left iliac artery by a percutaneously inserted balloon catheter, thus avoiding an additional retroperitoneal approach. The postoperative course was uneventful, and sciatic pain had resolved completely. The chosen strategy provides safe and successful surgical management of gluteal artery aneurysms.

Adult↗

Simultaneous coronary bypass and abdominal aortic surgery in patients with severe coronary disease--indication and results.

In patients with severe coronary artery disease (CAD) abdominal aortic surgery is still associated with high morbidity and mortality rates. Some patients will present with both symptomatic CAD and large, symptomatic abdominal aortic aneurysms (AAA) or end-stage aortic occlusive disease (AOD) that does not allow for a two-stage procedure. We report a series of 29 patients who underwent simultaneous coronary artery bypass graft surgery (CABG) and abdominal aortic surgery (25 AAA, 4 AOD). In the AAA group there were 23 males and 2 females with a mean age of 68 years (50-80). Sixteen patients presented with severe three-vessel disease. Ten patients had unstable angina. Aortic stenosis or insufficiency was present in two and one patient, respectively. Four patients with three-vessel disease and an ejection fraction below 30% presented with end-stage AOD and critical limb ischemia. Coronary bypass graft surgery was performed first. With the patient still on partial cardiopulmonary bypass, abdominal aortic surgery was carried out. Patients received an average of 3.1 coronary bypass grafts. Additionally, three aortic valves were implanted. Fourteen tube grafts and 15 bi-iliacal or bifemoral bifurcation grafts were placed in the abdominal aortic position. Additional vascular surgery was performed in five patients. Intraoperative management was without complication in all but one patient, who had intraoperative myocardial infarction (AOD group). Hospital mortality was 8% (2/25) in the AAA group. There was however substantial hospital morbidity (52.2%). The mean follow-up is 20.5 +/- 2.5 months. The actuarial survival rate at 3 years is 84.9%. It is concluded that combined CABG and abdominal aortic surgery is a reasonable option for patients who present with both severe CAD and symptomatic abdominal aortic disease. The continuation of CPB during aortic surgery may effectively prevent the adverse effects of infrarenal aortic clamping on a failing ventricle.

Actuarial Analysis↗

Successful surgery after complete disruption of the right bronchial system.

A case of successful surgical repair of a complex rupture of the right bronchial system in a twenty-nine-year-old man is presented. Complete primary bronchial reconstruction and intensive postoperative care was required to provide bronchial continuity and to avoid major pulmonary resection. Problems concerning diagnosis, surgical technique, and postoperative management are discussed. The good postoperative outcome may encourage bronchial repair instead of resection in complex bronchial disruptions.

Accidents, Traffic↗

Open heart surgery in the octogenarians--a study on long-term survival and quality of life.

This retrospective study analyzes the perioperative and long-term survival rate as well as the long-term quality of life of 54 patients (23 f/31 m), aged 80 years or older (80 to 87, mean 82.2, SD +/- 1.79 years), who underwent open heart surgery between January 1986 and December 1993. There were 23 patients with coronary bypass, 21 with aortic valve replacement, 1 with mitral valve replacement, 8 with combined aortic valve replacement and coronary bypass, and 1 with double valve replacement. Preoperatively, 26 of the patients were in New York Heart Association (NYHA) class IV, 28 patients in class III. The in-hospital mortality was 9.3% (5/54) over all and 6.1% (3/49) for elective procedures. Follow-up time ranged from 6 to 91 months (mean 26.2 +/- 16.5). Of 49 discharged patients, 6 (12.2%) died during the follow-up period. At the time of re-evaluation 21 patients were in NYHA class I, 24 patients in class II, and 4 in class III. There was a significant long-term benefit from the surgical intervention in 39 or the 54 patients. Of 43 survivors 41 were able to live on their own and 38 were able to handle their daily routine without help. Two patients were cared for in a nursing home. This long-term analysis demonstrates the benefits of cardiovascular surgery in octogenarians in terms of social integration and quality of life.

Aged↗

Tonsillar carcinoma in the early postoperative course following heart transplantation.

A 45-year-old male with end-stage dilative cardiomyopathy was referred for heart transplantation (HTx). Apart from severe heart disease the patient had an unremarkable medical history. Risk factors were heavy smoking and moderate consumption of alcohol. Preoperative screening including a thorough ENT status did not reveal any other risk factor or contraindication for heart transplantation. HTx was performed three months later. Immunosuppressive therapy consisted of triple-drug therapy and induction therapy with antithymocyte globulin. The patient had an uneventful perioperative course. One month after transplantation the patient developed a rapidly growing squamous cell carcinoma of the left tonsil with local metastasis. Because of the rapid growth and size of the tumor surgical treatment was already impossible at that early time. Despite a course of chemotherapy the tumor continued to grow; treatment was changed to radiation therapy resulting in partial remission. Cyclosporine and azathioprine dosages were reduced at the same time. 9 months following HTx the patient developed a rapidly growing recurrence. As there were no further therapeutic options, immunosuppressive therapy was completely discontinued with the patient's agreement. He died 2 months later. The rapid tumor growth and its early manifestation following HTx suggest a preexistent occult carcinoma. A more extensive and repetitive preoperative screening in HTx candidates who are heavy smokers should be considered.

Carcinoma, Squamous Cell↗

Monitoring of TPMT in heart transplant recipients under immunosuppressive therapy with azathioprine.

Azathioprine (AZA) is routinely used in double and triple immunosuppressive therapy after cardiac transplantation. In some cases it causes severe myelosuppression. The interindividual differences in AZA toxicity is probably due to differences in the drug metabolism. Thiopurine methyltransferase (TPMT) is thought to be the most important enzyme in the catabolism of AZA. A deficiency in this enzyme will presumably increase the availability of 6-mercaptopurine for the anabolic pathway thereby leading to increased cytotoxicity. A 65-year-old male underwent heart transplantation at our institution with an uncomplicated course. Immunosuppression consisted of cyclosporine, prednisolone, and AZA. Several weeks after the administration of AZA, the patient developed severe leukopenia. TPMT activity was then measured in this patient and found to be below the detection limit. Subsequently the patient died from multiorgan failure due to septicaemia. As a result of this experience, we started to screen all patients for TPMT deficiency. In 58 healthy controls, the mean activity was found to be 11.8 nmol/h/ml of red blood cells (RBC) while in 13 patients on our waiting list, the mean activity was found to be 11.97 nmol/h/ml of RBC. In 15 patients after heart transplantation and azathioprine treatment, the mean activity was found to be 17.2 nmol/h/ml of RBC. We suggest screening for TPMT activity in transplant patients with leukopenia under AZA therapy. If TPMT deficiency is present, the AZA dosage should be adjusted or alternative immunosuppressive regimens should be considered.

Aged↗

Thermal coronary angiography for intraoperative patency control of arterial and saphenous vein coronary artery bypass grafts: results in 370 patients.

BACKGROUND AND AIM OF THE STUDY: Early graft failure is often associated with technical failures and is therefore potentially avoidable. We used thermal coronary angiography (TCA) for intraoperative graft patency control in 370 patients undergoing routine coronary artery bypass graft surgery to determine whether consequent intraoperative bypass graft control may result in improved patency rates. METHODS: The temperature differences generated in between the myocardium and the grafts by injecting cold cardioplegic solution into the proximal end of a vein graft or by warmer blood running through an internal thoracic artery (ITA) graft were detected using three different infrared camera systems. The resulting "heat pictures" were evaluated for anastomotic patency and to outline graft anatomy. RESULTS: A total of 693 vein grafts were visualized. In 9.4% TCA failed to produce usable images. In the remaining 628 grafts, TCA revealed intraoperative patency in 98.8%. Out of 370 ITA grafts, only 14 could not be sufficiently visualized by TCA. Nineteen ITA occlusions (5.3%) were found: 5 intimal flaps; 11 suture imposed strictures; and 3 proximal ITA occlusions. All occluded grafts were subsequently revised or replaced. All sequential ITA as well as 15 right ITA grafts proved to have patent anastomoses. CONCLUSION: Using TCA an early graft dysfunction rate of 1% for vein grafts and 5.3% for ITA grafts could be demonstrated. Most occlusions were due to technical mistakes at the distal anastomosis. TCA outlines grafts and the attached coronaries by temperature differences without the need for a contrast agent. There is no interference with the surgical procedure. It is an ideal, noninvasive method to immediately document the success or failure of myocardial revascularization.

Adult↗

The Toronto SPV bioprosthesis: one-year results in 100 patients.

BACKGROUND: We studied the long-term results of heart valve replacement with the Toronto SPV bioprosthesis. METHODS: From March 1993 until July 1994 the Toronto stentless bioprosthesis was implanted in 100 selected patients with a mean age of 70.7 years. The predominant aortic valve lesion was stenosis in 94 and insufficiency in 6 cases. Eighty-eight patients received a valve 25 mm in diameter or larger. Additional coronary artery bypass grafting was performed in 37 cases. Hospital mortality was 4%. Seventy-four patients were seen at 6 months and 38 patients at 1 year follow-up. RESULTS: Structural deterioration, thromboembolism or hemorrhage were not encountered. Nonstructural dysfunction lead to reoperation in 1 patient. Another patient presented with endocarditis at 1 year postoperatively. There were no other valve-related complications. Echocardiographic mean pressure gradients ranged from 7.7 to 11.1 mm Hg postoperatively. There was a significant decrease in pressure gradients at 6 months of follow-up. Minimal aortic valve incompetence was seen in 3 patients. CONCLUSIONS: The Toronto stentless bioprosthesis has superior hemodynamics and is an excellent alternative to conventional stented bioprostheses. Long-term evaluation has to prove whether this promising new valve can live up to its expectations.

Adult↗

The effect of coronary bypass graft surgery for the prevention of sudden cardiac death: recurrent episodes after ICD implantation and review of literature.

Sudden cardiac death (SCD) accounts for at least 50% of the mortality of patients with ischemic heart failure. Ventricular arrhythmias are responsible for most cases of sudden cardiac death. There is some evidence that coronary artery bypass graft (CABG) surgery may reduce the incidence of recurrent episodes of SCD by prevention of myocardial ischemia. To test the hypothesis that CABG surgery is effective in the prevention of SCD, we compared the recordings of implantable cardioverter defibrillators (ICD) in patients who underwent ICD implantation alone (n = 64) or ICD implantation and concomitant CABG surgery respectively (n = 11). All patients had experienced out of hospital cardiac arrest. ICD recordings were obtained every 3 months and the number of recurrent episodes of ventricular tachycardia (VT) for each time period was noted. Three months following ICD implantation patients in the surgically treated group had an average of one episode of VT per patient as compared to 2.7 episodes in the nonsurgical group. This difference was observed during the following months as well. However, at no time (up to 18 months of follow-up) this difference reached statistical significance. There were no deaths in the surgically treated group. Although we could not demonstrate a statistical significant difference between the two groups, there was a tendency in the surgically treated group to have less episodes of recurrent VT than in the medically treated group. We, therefore, conclude that survivors of SCD presenting with multivessel coronary artery disease (CAD) should undergo coronary artery bypass grafting to prevent myocardial ischemia as the triggering event for lethal ventricular arrhythmias.

Coronary Artery Bypass↗

Intraoperative assessment of internal mammary artery bypass graft patency by thermal coronary angiography.

Following early graft failure in some patients during routine use of the internal mammary artery in coronary bypass surgery, a thermal coronary angiography technique was used for direct intraoperative control of internal mammary artery graft patency. This non-invasive method allows the evaluation of graft patency, anastomotic integrity and initial flow patterns without compromising the conduct of the surgical procedure. Internal mammary artery graft patency was controlled by thermal coronary angiography in 348 patients undergoing coronary bypass surgery. Graft anatomy, perfusion and distal run-off in the recipient native coronary artery was delineated by thermal coronary angiography using the temperature gradient of the warm perfusing blood and the cold myocardium. Thermal coronary angiograms were evaluated for graft and anastomotic patency as well as for direction and magnitude of internal mammary artery flow in the native coronaries. Some 348 internal mammary artery grafts, including 13 sequential grafts, were evaluated. Thermal coronary angiography failed for technical or logistical reasons in seven of 348 cases (2.0%). Thermal coronary angiography documented optimal anterograde flow in 282 of 341 cases (82.7%), reduced anterograde flow in 38 of 341 (11.1%) and no anterograde flow in 21 of 341 (6.2%). Using this approach 21 internal mammary artery graft occlusions were discovered, 18 at the anastomotic site and three at the site of the previously placed bulldog clamp. In addition, six unexpected distal native coronary stenoses and three internal mammary artery graft spasms were detected by thermal coronary angiography and found to be responsible for impaired anterograde flow. Based on these findings, 16 anastomotic revisions, nine additional vein grafts and two additional vein patches were performed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Hemodynamic assessment of the stentless Toronto SPV bioprosthesis by echocardiography.

Since March 1993 the Toronto SPVTM bioprosthesis has been implanted in 100 patients. Our prospective study evaluated the echocardiographic valve characteristics and the influence of the echocardiographic assessment on surgical technique. Transesophageal echocardiography (TEE) was applied before and during surgery, and transthoracic echocardiography (TTE) postoperatively. The average valve size implanted was 26.5 mm. Follow up was complete in 74 patients at six months and in 38 patients at one year. Pre-cardiopulmonary bypass (CPB) TEE valve sizing was accurate by +/- 1 mm in 81 patients as compared to mechanical sizing. Post-CPB valve closure was concentric in 99 patients. Minimal aortic incompetence was present in seven patients at one week, in two patients at six months and in one patient at one year. Mean pressure gradients ranged from 7.7 to 11.1 mmHg postoperatively. Overall mortality was 4%. One patient with non-structural dysfunction and another with endocarditis at one year postoperatively were reoperated successfully. At follow up there was a significant decrease in transvalvular pressure gradients and an increase in valve orifice areas. In 32 patients a decrease in left ventricular posterior wall (LVPW) hypertrophy was found (p < 0.001). There was a decrease in tissue depth and recurrence of the dynamic movement of the aortic root. It is concluded that TEE valve sizing is reliable for early valve selection. Valve incompetence is not a clinically relevant issue using the oversizing technique. Improved hemodynamics at follow up can be explained by remodeling of the aortic root and by a decrease in left ventricular hypertrophy. The excellent hemodynamic profile, resembling native aortic valve function, is impressive and has to be confirmed by long term evaluation.

Adult↗

Performance of indirect embolectomy aided by a new developed flush-suction catheter system. Forty-seven experimental embolectomy procedures in test animals.

Embolectomy by means of the Fogarty catheter is the therapy of choice in the event of acute occlusions of limb arteries. However, less invasive catheter procedures have become established means to perform embolectomies lately. In order to improve the results after using the above mentioned methods, we have developed a new embolectomy procedure. The system applied consists of a flush-suction catheter as well as a high pressure pump. There is a jet-suction unit on the head of the tubular two-lumen catheter to gather thromboembolic material from the circumference of the head, to erode the collected material and evacuate it. The flushing pressure is generated by the pump. For the experimental testing of the system, the flush-suction embolectomy has been performed in 19 pigs after 47 artificial produced extremities embolism. Angiographically and angioscopically it could be proved that even older thrombotic material could be removed completely and without significant trauma of the vessel. At the pathologic investigation of the vessel in which embolectomy had been performed in no case an essential vessel-wall damage could be found. In almost each case the embolic material was removed completely. Only in 5 cases (10.6%) we have distal microembolism. Due to the experimental tests, the system turns out to be reliable as far as the technique is concerned. In addition, in the event of clinical application, the system allows the expectation of a reduction of the time interval between diagnosis and therapy, as well as a percutaneous application.

Angiography↗

[Bronchial rupture and lung contusion in multiple trauma].

Tracheobronchial ruptures resulting from blunt chest trauma are rare events. Depending on their anatomical location and extension they may be nearly asymptomatic and escape early diagnosis, on the other hand they may induce an acute life-threatening situation with dramatic symptoms. The awareness of the different clinical and radiological findings may point to this lesion, the definite diagnosis, however, is made by bronchoscopy. A rapid surgical reconstruction intends to avoid severe late complications and to protect all uninjured lung areas for an adequate gas exchange in case of associated lung contusion. In patients with thoracoabdominal injuries, whether to perform thoracotomy or celiotomy first must be decided for each individual case depending on the urgency. The clinical course of a patient, who after a traffic accident suffered from main bronchus rupture, bilateral lung contusion, liver rupture and multiple fractures of the upper extremities illustrates these problems.

Adult↗

[Spontaneous pneumothorax as the initial symptom of bronchial cancer].

Spontaneous pneumothorax is caused by benign lung diseases in more than 95 percent. Mainly presenting in younger male patients between 20 and 40 years of age its prognosis is generally good.--On the other hand, pneumothorax as initial manifestation of bronchial carcinoma is a rare complication with poor prognosis. We report such a case of a 70 year-old man, review the literature and describe characteristical problems in diagnosis and therapy of very small bronchogenic tumors. Estimating that only 2 percent of all spontaneous pneumothoraces are coexisted with malignant lung diseases--either primary or secondary--this tumor-complication especially must be considered in older patients. Their prognosis may be improved entirely by rapid diagnosis and therapy.

Aged↗

Different ways of application of the implantable cardioverter defibrillator (ICD)--which is the current approach?

The implantable cardioverter defibrillator (ICD) has proved to be effective in patients at risk of sudden cardiac death (SCD). Because of the development of more effective lead- and defibrillator systems the surgical implantation modes have changed from extensive operative interventions (sternotomy, lateral thoracotomy) to less traumatical (subxiphoidal/subcostal approach) and less invasive (transvenous) techniques. Procedures with less operative damage may be offered to patients with reduced cardiac function. However, the kind of operative procedure to be performed must be decided individually. The different system configurations, their advantages and disadvantages as well as their complications are surveyed and discussed in the light of our patient population, 102 cases between 1984 and 1991, and the literature. Even when the "non thoracotomy" implantations will become the favoured method, the standard incisions by thoracotomy will still be of importance. Considering that major complications occur also in transvenous implant procedures and that cardiac operations have to be performed in 20-30% of the patients simultaneously, we suggest--following the recommendations of the North American Society of Pacing and Electrophysiology (NASPE)--that the devices be implanted exclusively in units for cardiac surgery in cooperation with rhythmologically well-trained cardiologists.

Aged↗