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Biomedical subjects

K Vatne

Publications and source records attributed to K Vatne.

At least 19 recordsLinked to original sources

Occurrence and management of fractured peripheral catheters in CSF shunts.

A series of 716 children underwent 2065 cerebrospinal fluid shunt procedures. Shunt failure due to fracture of the peripheral drain occurred 60 times, 38 times in ventriculo-atrial and 22 times in ventriculo-peritoneal shunts. The break occurred most commonly 2-4 cm above the neck incision in cardiac and just cephalad to the clavicle in abdominal drains. Fifty-nine ruptures occurred in Pudenz catheters (which were used in 82% of the shunts) and 1 occurred in a Holter drain (used in 17%). The fractured atrial catheters remained in situ (5/38) or were dislodged into the right cardiac ventricle (14/38), pulmonary arteries (9/38), right atrium (5/38) or hepatic veins (3/38). Two of the ruptured drains could not be located. Removal by a percutaneous transvascular snare technique was attempted in 27 cases and was successful in 24.

Adolescent

Hemodynamic evaluation of the CarboMedics prosthetic heart valve in the aortic position: comparison of noninvasive and invasive techniques.

Seventy-three patients with a CarboMedics aortic bileaflet valve prosthesis were examined by Doppler ultrasonography, and 27 of them were also assessed by transseptal catheterization. The ultrasonic mean systolic gradient was 17.1 +/- 5.6 mm Hg for valve size 19 mm, falling gradually with increasing valve size to 6.8 +/- 2.5 mm Hg for size 27 mm. The catheter mean systolic gradient was consistently smaller than the ultrasonic gradient (4.3 +/- 4.8 mm Hg), but Tobit regression analysis showed a significant association between the two methods. In all patients both methods revealed negligible to small amounts of retrograde leakage, which is assumed to be a normal finding for this valve. The effective flow areas of the valves calculated from the ultrasonic data were similar to the in vitro calculated flow areas. The hemodynamic potential of this valve is therefore completely utilized in vivo. The effective orifice area corrected for body surface area increased with increasing valve size, which demonstrates a moderate valve-patient mismatch.

Adult

Long-term clinical results of percutaneous transluminal angioplasty in transplant renal artery stenosis.

Twenty-five patients with transplant artery stenosis were identified among 1141 renal graft recipients. Impaired graft function (9 patients), hypertension (4 patients) or both (12 patients) were the indications for arteriography. All were treated by percutaneous angioplasty (PTA). The immediate technical success rate was 88% and actuarial graft survival was 88% and 80% at 2 and 5 years respectively. The long-term success rate on graft function was 67% (median observation time 24 months) and on hypertension 63% (median observation time 23 months). Six patients needed rePTA (8 procedures) and in only one patient was surgical repair performed. No case of graft loss due to PTA was recorded and in only one case did occlusion of a segmental artery lead to impairment of graft function. Minor complications were recorded in four other cases and in no case was surgical intervention necessary. Based on these results we favour PTA as a first-line interventional procedure in transplant renal artery stenosis, and the need for surgical repair has been low.

Adult

Patency of the internal mammary artery used as sequential graft.

In 28 patients with the left internal mammary artery (IMA) used as a sequential coronary artery graft, clinical and angiographic evaluation was made 19-47 months postoperatively. Patency was 96% in the proximal anastomoses and 93% in all the anastomoses. Angiography, however, showed optimal function in only 75% of the distal graft ends. These observations indicate that routine use of left IMA as a sequential graft should be restricted to experienced surgeons. Clinical and angiographic findings did not always correlate, emphasizing that evaluation of IMA-graft patency should include angiography.

Adult

Single lung transplantation. Surgical experiences with the first seven patients.

Seven single lung transplants are reported. The patients were severely disabled and oxygen dependent below sixty years of age with a poor prognosis. Diagnosis were alfa 1-antitrypsin deficiency (3), sarcoidosis (3) and idiopathic emphysema (1). Multiorgan-harvesting including six hearts, was performed in local or distant hospitals (3). Partial cardiopulmonary bypass simplified transplantation. The surgical procedure was modified with a direct transpericardial approach. Soft tissue wrapping by a vascularized pedicle secured the bronchial anastomosis. The four drug immunosuppressive regimen included cyclosporin A, azathioprine, steroids and antithymocyte globulin. Primary graft function was excellent. Six patients survived the postoperative period and are alive 5-19 months post transplant. Transbronchial biopsies and lung function studies have been helpful in detecting pulmonary rejections. Patient rehabilitation is satisfactory in most patients with improvement in physiologic parameters.

Adult

Restenosis after percutaneous transluminal coronary angioplasty.

Restenosis after percutaneous transluminal coronary angioplasty was demonstrated in 61 (29%) of 210 successfully treated patients. Mostly it occurred within 4 months after treatment and in arteries less than 3 mm in diameter. Careful clinical follow-up is therefore particularly important early after angioplasty of smaller arteries. Redilation can be performed without increased risk of restenosis.

Angioplasty, Balloon, Coronary

[Restenosis after coronary angioplasty].

Angiography of 169 patients who had been treated successfully with PTCA showed restenosis in 61. Of these, 38 were successfully treated with a new PTCA, and six developed a new restenosis. Restenosis usually appears during the first four months after PTCA in vessels with a diameter less than three millimeters. The authors emphasize the importance of careful clinical follow-up.

Angioplasty, Balloon, Coronary

[Treatment of unstable angina pectoris].

We present the results of an acute revascularisation program for unstable angina. Of the 63 consecutive patients included in the program 61 had significant coronary artery disease. Coronary bypass grafting was performed in 39 and percutaneous transluminal angioplasty in 9. There were two perioperative myocardial infarctions and one death in hospital. 13 patients were found unsuitable for revascularisation. At follow-up (14-26 months) 60 patients were still alive (95%). In the revascularised group 30 patients (65%) were free of angina pectoris. Accordingly, in patients who do not respond to medical therapy, acute revascularisation may be performed with low operative mortality, low incidence of perioperative myocardial infarctions, and good long term results.

Angina Pectoris

Colloid versus crystalloid cardioplegia. A prospective, randomized clinical study.

The effects of adding colloid (dextran 40, Rheomacrodex) to cardioplegic solution were studied in 55 men undergoing bypass grafting for uncomplicated coronary artery disease. The patients were randomly allocated to group I (n = 27), in which 35 g dextran 40 was added to the St Thomas II cardioplegic solution, or group II (n = 28), which received a standard crystalloid cardioplegic solution. The groups were comparable in regard to preoperative and intraoperative data. In group I the pulmonary vascular resistance index was transiently elevated after extracorporeal circulation and both oxygen consumption and arteriovenous oxygen content difference 2 hours postoperatively were greater than in group II, suggesting better microcirculation. Postoperative normalization of the chest X-rays was more rapid in group I. The clinical course was similar in the two groups.

Cardioplegic Solutions

Is cold, cardioplegic solution harmful to the lungs?

The effects of pulmonary flush with cold cardioplegic solution were investigated in 55 patients undergoing coronary artery bypass grafting. Extracorporeal circulation with bicaval cannulation was used in all cases, and single-dose cardioplegic solution was injected into the aortic root. In one of two randomly selected groups (n = 27) the cardioplegic solution was allowed to pass through the lungs and then evacuated via a left ventricular vent. In a second group (n = 28) the vent was first temporarily placed in the right atrium for evacuation of the cardioplegic solution, and the aortic root was vented later. Hemodynamic, metabolic, hematologic and radiographic changes were studied during the early postoperative period. No harmful effects of the pulmonary passage could be demonstrated. On the contrary, a protective effect was indicated, as the pulmonary vascular resistance index was reduced immediately and for 2 hours postoperatively. The ratio of left ventricular to right ventricular stroke work in the early postoperative period gave the same indication.

Cardioplegic Solutions

Failure of combined acetylsalicylic acid and dipyridamole to prevent occlusion of aortocoronary venous bypass graft.

Patients scheduled to receive at least three aortocoronary venous bypass grafts were randomized to active medication or to placebo. The former were given dipyridamole (DP) preoperatively and acetylsalicylic acid (ASA) was added after the operation. For the next 3 months they received DP 75 mg and ASA 325 mg thrice daily. The placebo regimen was identical and the study was conducted with double-blind technique. One patient in each group died. DP-ASA was discontinued in six patients because of gastrointestinal side effects (bleeding peptic ulcer in 2 cases). Angiography after 3 months revealed the patency rate of individual grafts to be 68% in the DP-ASA group and 77% in the placebo group. DP-ASA therefore did not prevent occlusion of aortocoronary venous bypass grafts.

Aspirin

Digital subtraction angiography (DSA) in the evaluation of brain death. A comparison of conventional cerebral angiography with intravenous and intraarterial DSA.

Demonstration that intracranial circulation has ceased is the ultimate proof of brain death. This study was performed to evaluate digital subtraction angiography (DSA) compared with conventional cerebral angiography in the diagnosis of brain death. Intravenous as well as intraarterial DSA was found suitable in the diagnosis of arrested intracranial circulation.

Adolescent

Angiographic and echocardiographic observations in surgical patients with atrial myxoma.

In a series of 18 patients with atrial myxoma (16 left, 2 right) the tumors were consistently identified by right ventriculography and generally visualized by left ventriculography in patients with left atrial myxoma examined owing to concomitant mitral insufficiency caused by tumor invasion at the site of mitral valve closure. Echocardiography was suited to early diagnosis of suggested tumor. Pseudoaneurysms in the cerebral and coronary arteries, apparently caused by myxomatous emboli with weakening of vessel lumen, were noted in several patients; therefore, selective coronary and cerebral arteriography should be performed preoperatively in patients with symptoms of thromboembolism. We stress that echocardiography should be performed routinely after surgery to disclose recurrences, while arteriographic control studies should be added in cases with vascular anomalies seen preoperatively.

Adult

Aortic regurgitation associated with ventricular septal defects in adults. Clinical course, haemodynamic, angiographic and echocardiographic findings.

In 125 consecutive patients, aged greater than or equal to 10 years (mean 27, range 10-64), evaluated for isolated ventricular septal defects (VSD) the initial prevalence of aortic regurgitation (AR) was 12/125. Forty-one patients were operated on, and post-operative mortality was 3/6 in patients operated on for VSD and AR and 1/35 in those operated on for VSD alone. All but one of the patients have been followed until death or beyond the age of 30 years (mean 42, range 31-73) and a prospective restudy has been performed after a mean observation time of 15 years (range 4-21). The incidence of new cases of AR arising during this period was 10/111. AR was severe in 5 cases (one died from heart failure), moderate in 1 and mild in 4. Surgical repair of AR and VSD was performed in 3 cases. Common characteristics of patients who developed AR were advanced age, male sex, history of bacterial endocarditis, small subaortic VSDs and tricuspid aortic valves without prolapse. Echocardiography revealed larger aortic root diameter (p less than 0.001), increased eccentricity factor (p less than 0.001) and increased left ventricular dimensions (p less than 0.02) in those with complicating AR. AR in adults with VSD may have an unpredictable clinical course; it may be difficult to assess clinically and the need for close clinical control is emphasized. Echocardiography remains of considerable value in selected cases.

Adolescent