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Biomedical subjects

D Nykanen

Publications and source records attributed to D Nykanen.

27 records · Page 2Linked to original sources
PubMed1997

Coil embolization of a coronary artery to pulmonary artery fistula from an antegrade approach.

Transcatheter embolization of coronary artery fistulae has become the therapy of choice for this uncommon lesion. We report a case in which transcatheter embolization was performed in a nine-year-old boy with a large fistula originating from the proximal portion of the left anterior descending artery and communicating with the pulmonary artery and the right coronary artery. The fistula was occluded 'antegrade' by cannulating the connection with the pulmonary artery to deliver occluding coils.

Arterio-Arterial Fistula↗
PubMed1997

Balloon angioplasty of recurrent coarctation: a 12-year review.

OBJECTIVES: This study was undertaken to investigate the long-term outcome of balloon angioplasty for recurrent coarctation of the aorta in a large series of patients. BACKGROUND: Balloon angioplasty has become the standard treatment for residual or recurrent aortic coarctation. Despite the widespread use of this treatment modality, there are few data outlining the long-term outcome of a large patient cohort. METHODS: Clinical, echocardiographic, hemodynamic and angiographic data on 90 consecutive patients who underwent balloon angioplasty between January 1984 and January 1996 were reviewed. RESULTS: Mean systolic pressure gradients were reduced from 31 +/- 21 to 8 +/- 9 mm Hg after dilation (p = 0.0001). The mean diameter of the stenotic site, measured in the frontal and lateral views, increased by 38% and 35%, respectively (p = 0.001). Neurologic events occurred in two patients, with one death. An aortic tear occurred in one patient, requiring surgical intervention. Optimal results were defined as a postprocedure gradient < 20 mm Hg and were obtained acutely in 88% of patients. At long-term follow-up (12 years), 53 (72%) of 74 patients with an early optimal result remained free from reintervention. Transverse arch hypoplasia, defined as an arch dimension < 2 SD below the mean for age, was the primary predictor of the need for reintervention. CONCLUSIONS: Although the majority of patients undergoing percutaneous balloon angioplasty for recoarctation of the aorta will achieve long-term benefit, the need for further surgical intervention in those with transverse arch hypoplasia remains high.

Adolescent↗
PubMed1997

Balloon dilation of severe aortic stenosis in the neonate: comparison of anterograde and retrograde catheter approaches.

OBJECTIVES: We sought to compare anterograde and retrograde balloon dilation of severe aortic valve stenosis in neonates. BACKGROUND: There is a high incidence of iliofemoral artery complications after retrograde balloon dilation of the aortic valve in the neonate. Therefore, a nonarterial technique of catheter access to the aortic valve would be worth exploring. METHODS: Group 1 included 11 consecutive patients (median age 6 days, range 1 to 42; median weight 3.5 kg, range 2.16 to 4.25) undergoing attempted anterograde dilation through a femoral venous approach. Group 2 included 15 patients (median age 3 days, range 1 to 35; median weight 3.4 kg, range 2.5 to 4.4 kg) who underwent attempted retrograde dilation, including 2 in whom attempted anterograde approach had failed. RESULTS: The valve was successfully crossed in 9 of 11 anterograde and 13 of 15 retrograde dilations. In both groups, the peak gradient across the valve decreased significantly (both p = 0.001). On echocardiography, the jet width of the aortic incompetence/ annulus diameter ratio was 0.16 +/- 0.08 (mean +/- SD) after anterograde and 0.51 +/- 0.24 after retrograde dilation (p = 0.03), possibly because of unrecognized valve leaflet perforation. Two patients in group 1 developed persistent, mild mitral insufficiency. Femoral artery thrombosis developed in one patient after anterograde dilation and in eight after retrograde dilation (p = 0.03). CONCLUSIONS: This series demonstrates that an anterograde approach for balloon angioplasty of severe neonatal aortic valve stenosis is feasible, achieves good hemodynamic relief and lessens morbidity compared with retrograde arterial techniques.

Age Factors↗
PubMed1995

Endovascular stents in the pulmonary circulation. Clinical impact on management and medium-term follow-up.

BACKGROUND: The use of endovascular stents to relieve obstructions in the setting of non-balloon dilatable pulmonary artery stenosis has been encouraging. The benefits in management and the potential for restenosis, however, have not been defined. This study attempts to assess the impact of such implants on clinical outcomes and the pattern of stent incorporation within the vessel wall. METHODS AND RESULTS: Fifty-five balloon-expandable stents were implanted in 42 patients 6.1 +/- 4.7 years of age. Patients were followed prospectively (median, 15 months) and recatheterized 1 year after implantation. Thirty-eight patients had the implants positioned percutaneously (49 implants), while 4 patients (6 implants) had intraoperative implantations. There was a diameter increase in the stenotic area of 109 +/- 79% (P < .0001) and a gradient reduction of 74 +/- 26% (P < .0001). Twelve stents straddled the orifice of side-branch pulmonary arteries and reduced flow to the branch vessel acutely in 7 patients. Twenty-nine patients underwent recatheterization, and various degrees and locations of acquired intraluminal narrowing were observed in all cases, particularly in areas of diameter mismatch between the stented and nonstented vessels. Eleven patients had further dilation with diameter improvement. Of the 38 patients who underwent percutaneous implantation, planned surgery for pulmonary artery stenosis was avoided in 33 and deferred in 4 patients. One patient who was considered inoperable had stent implantation as a palliative procedure. Symptomatic improvement was reported in 27 patients, and 15 patients remained asymptomatic. CONCLUSIONS: Endovascular stents have a role in the treatment of pulmonary artery stenoses and positively affect clinical care. The stenosis relief, however, may be tempered by the development of intraluminal stent obstruction, which may require redilation (15 of 55 stents) and mandates long-term follow-up.

Adolescent↗
PubMed1995

Endovascular stents in pediatric cardiovascular medicine.

Acquired or de novo vascular obstructions can adversely affect the outcomes of management algorithms for children with congenital heart lesions. Although surgical repair is frequently feasible, some acquired or congenital obstructions are difficult to address in the operating theater. Discussed is the recent experience with endovascular stents to relieve such stenoses, and their impact on patient care.

Animals↗
PubMed1991

Evaluation of performance characteristics of disposable bag-valve resuscitators.

OBJECTIVE: To evaluate the performance characteristics of disposable bag-valve resuscitators. DESIGN: Single and multitrial tests under simulated clinical conditions. Results of multitrial tests were analyzed by multivariate analysis of variance. SETTING: A pulmonary laboratory in a university hospital. METHODS: We evaluated eight DRs to determine: a) physical characteristics, including the potential for misassembly; b) FIO2 of 1.0 and flow rates of 10 L; c) tidal volume (VT) (male and female operators) using one and two hands; and d) cycling rates at 5 degrees, 20 degrees, and 48 degrees C. RESULTS: All resuscitators met the minimum requirements of the Canadian Standards Association and the American Society for Testing and Materials. However, the CPR and LSP could be assembled incorrectly for use. Three units (B Sav, Pulm, and MPR) delivered significantly less than 80% oxygen (overall p less than .05). Significant increases were seen in VT using two hands vs. one hand (1176 vs. 960 mL, p less than .001) and males vs. females using two hands (1284 vs. 1102 mL, p less than .02). One unit (B Sav) could only be used with two hands. The maximum cycling rates for all units increased significantly (p less than .05) with an increase in temperature from -5 degrees to 20 degrees to 40 degrees C. However, two units (Bag E and MPR) failed to deliver 20 breaths/min at -5 degrees C, while the B Sav and Pulm valves became dysfunctional at 48 degrees C. CONCLUSIONS: While these DRs meet the minimum standards, they should be chosen carefully and evaluated before application in the clinical environment.

Disposable Equipment↗
PubMed1991

Comparison of a topical mixture of lidocaine and prilocaine (EMLA) versus 1% lidocaine infiltration on wound healing.

We compared a eutectic mixture of lidocaine and prilocaine (EMLA, Astra Pharmaceuticals, Inc) with 1% lidocaine infiltration to determine the effect on wound healing in a prospective single blind study using the rat model. Thirty-six wounds were assessed. No clinical or histologic evidence of infection or necrosis was present in any wound. Five wounds (two in the lidocaine and three in the EMLA group, P = 1.0) demonstrated a widened scar owing to healing by secondary intention following suture disruption. There was no significant difference between groups in the degree of inflammation (P = 0.08). We conclude that EMLA does not affect wound healing adversely and is comparable to 1% lidocaine infiltration in the animal model. Further study to determine its anesthetic effect in laceration repair is presently being undertaken.

Administration, Topical↗
PubMedDate not supplied

Endovascular stents in congenital heart disease.

Acquired or de novo vascular obstructions can adversely affect the outcomes of management algorithms for children with congenital heart lesions. Although surgical repair is frequently feasible, some acquired or congenital obstructions are difficult to address in the operating theater. Presented is the recent experience with endovascular stents to relieve such stenoses, and their impact on patient care.

Algorithms↗