Magnetic resonance imaging of the iliofemoral arteries after balloon dilation angioplasty of aortic arch obstructions in children

Low profile sheaths in pediatric neurointervention: a multicenter experience

BACKGROUND

Pediatric neurointervention is challenged by the appropriateness of adult catheters and devices. This multicenter report on the smallest groin access sheaths offers technical notes and clinical outcomes in the pediatric neurointerventional population.

METHODS

All pediatric neurointerventional cases from 2019 to 2021 were reviewed for use of a 3.3F Pediavascular or a 4F Merit Prelude Ideal low profile sheath. Hospital records were reviewed for complications and technical notes and compared with arterial groin access with the 4F Terumo Pinnacle in infants less than 1 year old, before the low profile sheaths at one author's institution were introduced.

RESULTS

From January 1, 2019 to March 31, 2021 there were 347 procedures performed at Boston Children's Hospital and University of Wisconsin. Forty-four procedures in 26 patients were identified in which a 3.3F (38 cases, 20 patients) or 4F (6 cases, 6 patients) sheath was used. The average age was 2.2 years (1.5 days to 18 years). Retinoblastoma intra-arterial chemotherapy infusion (18 of 44) was the most common indication. The remaining procedures comprised vein of Galen embolization (12), diagnostic cerebral angiography (13), and one preoperative tumor embolization. Morbidity included a groin hematoma and decreased pulses (4.5%). No major groin complications occurred. There was no statistically significant difference compared with the historical cohort (132 procedures), which had seven instances of decreased pulses (5.3%, p>0.05).

CONCLUSION

The 3.3F Pediavascular and 4F Merit Prelude Ideal sheaths are easily incorporated into the pediatric neurointerventionalist's armamentarium for infants and readily accommodate various microcatheters for distal embolization and catheterization.

Percutaneous catheter interventions via Glidesheath Slender in small children

BACKGROUND

Catheterization in small children should be performed with the lowest diameter introducer sheaths to prevent permanent vessel damage. The objective of this study is to evaluate the clinical safety and efficacy of the Glidesheath Slender in small children.

METHODS AND RESULTS

We present a group of 52 patients (male: n = 36) with median age 118.5 days (min. 3; max. 1302), median weight: 5.3 kg (min. 1.4; max. 14.0), median height: 60.5 cm (min. 39; max. 102), and median body surface area 0.28 m2 (min. 0.12; max. 0.63) in whom percutaneous catheter interventions (n = 55) were performed via a Glidesheath Slender. In 49 children, the intervention was performed from femoral access (artery n = 35; vein n = 14) in 2 from the axillary arterial access and in 1 from the jugular venous access. In all patients, the vessel access was obtained under ultrasound guidance. After the catheterization, the pulse on the peripheral arteries (posterior tibial artery or radial artery) was palpable in all patients, and no signs for vessel dysfunction were present.

CONCLUSION

The Glidesheath Slender effectively reduces the outer sheath diameter for various types of interventions in small children by one French, reducing the risk of vessel complications (stenosis, occlusion). Interventions via Glidesheath Slender in small patients are safe and feasible and extend the transcatheter possibilities in small children with congenital heart diseases.

Intra-Arterial Chemotherapy for Retinoblastoma in Infants ≤10 kg: 74 Treated Eyes with 222 IAC Sessions

BACKGROUND AND PURPOSE

Intra-arterial chemotherapy for retinoblastoma has dramatically altered the natural history of the disease. The remarkable outcomes associated with a high safety profile have pushed the envelope to offer treatment for patients weighing ≤10 kg. The purpose was to determine the efficacy and safety of IAC infusions performed in infants weighing ≤10 kg with intraocular retinoblastoma.

MATERIALS AND METHODS

A retrospective chart review was performed for patients diagnosed with retinoblastoma and managed with intra-arterial chemotherapy.

RESULTS

The total study cohort included 207 retinoblastoma tumors of 207 eyes in 196 consecutive patients who underwent 658 intra-arterial chemotherapy infusions overall. Of these, patient weights were ≤10 kg in 69 (35.2%) and >10 kg in 127 (64.8%) patients. Comparison (≤10 kg versus >10 kg) revealed that the total number of intra-arterial chemotherapy infusions was 222 versus 436. Periprocedural complications were not significantly different (2 [0.9%] versus 2 [0.5%]; P = .49). Cumulative radiation exposure per eye was significantly lower in infants weighing ≤10 kg (5.0 Gym² versus 7.7 Gym²; P = .01). Patients weighing ≤10 kg had a greater frequency of complete tumor regression (82.6% versus 60.9%; P = .02). Mean fluoroscopy time was not significantly different (7.5 versus 7.2; P = .71). There was a significant difference in the frequency of enucleation (16 [21.6%] versus 52 [39.1%]; P = .01). Patients weighing ≤10 kg had greater number of aborted procedures (12 [5.4%] versus 7 [1.6%]; P = .01). On multivariate analysis, weight ≤10 kg was not an independent predictor of complications or procedure failure.

CONCLUSIONS

Intra-arterial chemotherapy in patients weighing ≤10 kg is a safe and effective treatment.

Arterial Recanalization for Access for Arterial Intervention in Children: Techniques and Outcomes

PURPOSE

To assess technical success of arterial recanalization in children requiring repeated arterial access and intervention.

MATERIALS AND METHODS

Over 14 years, 41 attempts to cross 30 arterial occlusions were made in 22 patients (13 male, 9 female). Median patient age was 12 months (15 days-14 years), and weight was 7.6 kg (3.0-77.3 kg). Techniques and outcomes were recorded.

RESULTS

Twenty-five of 41 (61%) attempts at crossing an arterial occlusion were successful. Nineteen of 30 (63%) first attempts to cross occlusions were successful, and 6 of 11 (55%) repeat attempts were successful. The occluded segments were combinations of common femoral artery (n = 4), external iliac artery (n = 36), common iliac artery (n = 11), and aorta (n = 1). Complications occurred in 5 of 41(12%) attempts: 3 minor complications (hematoma, extravasation, and transient leg ischemia) and 2 major complications (rupture and thrombosis).

CONCLUSIONS

Arterial access by recanalization of occluded segments is technically feasible in children, with a low complication rate.

Outcomes using a clinical practice pathway for the management of pulse loss following pediatric cardiac catheterization

OBJECTIVE

Objectives To describe the results of a clinical practice pathway (CPP) for the management of postcatheterization pulse loss in a children's hospital.

BACKGROUND

Standardized approaches to the diagnosis and management of postcatheterization arterial thrombus are lacking. As a result, substantial practice variation exists.

METHODS

Data collected prospectively for quality improvement purposes were retrospectively reviewed.

RESULTS

Since initiation of the CPP, 93/1,672 (5.4%) catheterizations resulted in pulse loss at a median patient age and weight of 73 days (1 day-5.8 years) and 4.8 kg (2-14.1 kg). Arterial thrombus was documented by ultrasound (US) in 85. Of these, 66 resolved by 12 weeks of therapy, seven patients died, and four were lost to follow-up before completing treatment. Eight patients had persistent thrombus despite a full treatment course (89% success rate in those able to complete treatment). Of patients treated with unfractionated heparin as initial therapy, 46% (17/37) achieved a therapeutic partial thromboplastin time within 12 hr with 19% (67/343) of all levels therapeutic. As a result, the CPP was modified to use enoxaparin as first line agent, of which 57% (41/72) had a therapeutic anti-Xa level after the 2nd dose and 88% by the 4th dose. No bleeding complications were observed. A priori established process metrics were achieved.

CONCLUSIONS

A CPP utilizing early initiation of anticoagulation and US to aid diagnosis of postcatheterization arterial thrombus and response to therapy is feasible and effective. In those able to complete up to 12 weeks of treatment, resolution occurs in nearly 90%. © 2014 Wiley Periodicals, Inc.

Post-catheterisation arterial thrombosis in children--pathophysiology, prevention, and treatment

Lower limb ischaemia is the most frequent complication of cardiac catheterisation in children. It is often overlooked, but it can cause significant disability and may limit arterial access sites to repeat diagnostic or interventional catheterisations. A narrative review of the literature on arterial access site thrombosis in children was carried out with a special focus on current evidence that supports preventive and treatment strategies. Anticoagulation, thrombolysis, and thrombectomy have been used successfully to treat arterial access site thrombosis. However, it is not completely established which is the role of each treatment modality and what is the most appropriate timing to deliver it. Therefore, diagnostic and therapeutic strategies have to be prospectively investigated, particularly for clarifying the role of new pharmacologic interventions and of percutaneous and surgical thrombectomy in the current era.

Addressing challenges in 4 F and 5 F arterial access for neurointerventional procedures in infants and young children

BACKGROUND

Among the technical challenges involved in safely performing neuroendovascular procedures in infants are limitations on the size of femoral arterial access catheters. Restricting groin access to 4 F and 5 F systems constrains the range of procedures that can potentially be performed.

METHODS AND RESULTS

We present here a consecutive series of transfemoral angiographic procedures in children with no permanent and one transient case of groin morbidity related to femoral access. We illustrate two strategies for using 4 F and 5 F systems for interventions in a manner that enables such techniques as balloon assisted coil embolization and the deployment of triaxial catheter systems to be used.

CONCLUSIONS

Extremely low groin morbidity is achievable using rigorous parameters around femoral catheterization in children. With creative approaches to working within the limitations of the access vessel size, complex endovascular neurointerventions are possible, even in the youngest infants.

Covered stents in the management of coarctation of the aorta in the adult: initial results and 1-year angiographic and hemodynamic follow-up

BACKGROUND

The purpose of this study was to determine the safety and efficacy of the Cheatham Platinum covered stent in adults with coarctation of the aorta.

METHODS

Adults with native coarctations (n=14); previous coarctation surgery (n=4), stenting (n=1) or both surgery and endovascular therapy (n=3) underwent percutaneous intervention with a covered stent. Indications for stenting in those with previous intervention were recurrent coarctation (n=4), aneurysm formation at the site of previous intervention (n=2) or both recurrent coarctation and aneurysm formation (n=2).

RESULTS

Twenty-three covered stents were placed in 22 patients (mean age 39+/-14 years, n=11 males). Successful device deployment was achieved in all patients, although one patient required a second covered stent for aortic wall rupture. Peak systolic gradient across the coarctation site decreased from 29+/-17 to 3+/-5 mm Hg (p<0.001) immediately following implant and this was maintained (6+/-9 mm Hg, p=0.001) at invasive assessment, 12 months after the initial procedure. Right arm systolic blood pressure significantly declined (p=0.02), as did the number of antihypertensive medications per patient (p=0.03). At angiographic follow-up, post-stenotic dilatation of the aorta decreased from 32+/-8 mm to 30+/-8 mm (p=0.001), however, no stent recoil was observed.

CONCLUSIONS

Covered stents are safe, durable and efficacious in the management of coarctation of the aorta. Angiography and hemodynamic assessment is an effective method of screening for recurrent coarctation, and arch and vascular complications after stenting in adults.

Complications of pediatric cardiac catheterization: a review in the current era

OBJECTIVE

To determine types of complications and risks associated with pediatric cardiac catheterization in the current era.

BACKGROUND

Pediatric cardiac catheterization is an important diagnostic and therapeutic tool. Although in the last decade, there have been significant improvements in technology and equipment, the risk for complications remains, adversely effecting outcomes.

DESIGN

The clinical records of 11,073 children undergoing cardiac catheterizations between January 1994 and March 2006 were reviewed to identify procedures associated with complications within the first 24 h after catheterization. All children's electronic and paper chart records were reviewed to obtain demographic, procedural, and treatment data.

RESULTS

A total of 858 (7.3%) complications (classified as major or minor) occurred in 816 studies (510 males, 63%), in children ranging in age from 8 h to 20 years (median 4.13 years). There were 195 major (22%) and 663 (78%) minor complications. Vascular complications represented the majority (n = 278; 32.4%) and were major in 53 instances (P < 0.0001). Twenty-five children died within 24 h (0.23% of total case numbers). Independent risk factors for a complication included young patient age (<6 months), male gender, inpatient status, and year of catheterization.

CONCLUSIONS

Complications continue to be associated with pediatric cardiac catheterization, although overall incidence appears to be decreasing. Patient age, gender, and inpatient status continue to be risk factors for morbidity and mortality. Efforts at improving equipment for flexibility and size, and developing strategies for the use of alternative methods for catheter access should be encouraged.

Vascular ultrasound imaging to study immediate postcatheterization vascular complications in children

Vascular occlusion is the major complication of percutaneous cardiac catheterization in children. This is a prospective study to evaluate post catheterization vascular complications in 120 consecutive children with the help of vascular ultrasound and Doppler imaging. Ultrasound imaging of both iliac and femoral veins and arteries was done one hour prior and 24 hours after cardiac catheterization. Patients with prior thrombus or occlusion of femoral/iliac vein or artery due to previous cardiac catheterization were excluded from the study. Age of the patients ranged from 22 days to 12 years with a mean of 56 months and weight ranged from 3 to 57 kg with a mean of 14.3 kg. Procedure time was less than 60 minutes in 74 patients (61.66%) and more than 60 minutes in 46 patients (38.33%). 4F sized arterial sheath was used in 108 patients. 5F or bigger sized arterial sheath was used in remaining 12 patients. Incidence of arterial occlusion was higher in patients weighing less than 10 kg (16%) as compared with patients weighing more than 10 kg (5.5%) {P = 0.031}. Arterial thrombosis was more in infants (16%) as compared with older children (7%) {P = 0.203} Prolonged procedure time or use of larger sized sheath did not have higher incidence of arterial occlusion. Venous thrombosis was found in 2 patients (1.66%) who had 5F venous sheath. One patient had arterio venous fistula. Our study shows vascular ultrasound imaging can provide anatomical details of femoral and iliac vessels and is a easier and accurate method of assessing post-catheterization vascular complications in children.

Management of valvar aortic stenosis in children

What is the best treatment for the child with valvar aortic stenosis-balloon or surgical valvotomy?

Magnetic resonance angiography of the pediatric abdomen and pelvis

Although abdominal and pelvic vascular disease is much less common in children than in adults, MR angiographic techniques widely used in adults can also be readily applied in the pediatric population with suspected vascular disease. MR techniques, equipment, and image analysis software are in a continual state of development and refinement. Given the advantages of MR angiography (i.e., its absence of ionizing radiation, capability to obtain images without iodinated contrast material, and limited invasiveness), the applications of MR angiography in the pediatric abdomen and pelvis are likely to continue to increase.

Paraplegia following percutaneous balloon angioplasty of aortic coarctation: a case report

Balloon angioplasty of recurrent coarctation of the aorta is considered a low-risk procedure with high success rate. In the literature, the major complications are death, rupture of the aorta, recoarctation, aneurysm formation, cerebrovascular accident, and femoral artery thrombosis. Spinal cord ischemia as an unusual complication of balloon angioplasty is reported.

Safety and outcomes of thrombolysis with tissue plasminogen activator for treatment of intravascular thrombosis in children

OBJECTIVES

In this study, we tried to determine the safety and outcomes of thrombolysis with tissue plasminogen activator of intravascular thrombus.

STUDY DESIGN

Eighty consecutive children were treated between 1985 and 1999 in a tertiary care setting in a retrospective case series. There were 65 arterial thrombi (56 after cardiac catheterization) and 15 venous thrombi treated with tPA at an average dose of tPA of 0.5 mg/kg/hour for a median duration of 6 hours.

RESULTS

Clot resolution was complete in 65% of children, partial in 20%, and there was no effect in 15%. There were major complications in 40%, minor complications in 30%, and no complications in 30%. Two patients had cerebral ischemia secondary to hypotension because of profound bleeding, with intracranial hemorrhage in 2 additional patients. Clot resolution was not related to patient age or weight, dose, and duration of tPA therapy and fibrinogen levels. However, complications were more likely in patients who weighed less, had a longer duration of therapy, a greater decrease in fibrinogen levels, and who failed to have resolution of their clot.

CONCLUSIONS

tPA therapy can be effective in the thrombolysis of intravascular thrombus in children, but is associated with a low margin of safety and an unknown risk-benefit ratio.

Balloon angioplasty of native coarctation: clinical outcomes and predictors of success

OBJECTIVES

We sought to investigate the clinical impact of balloon angioplasty for native coarctation of the aorta (CoA) and determine predictors of outcome.

BACKGROUND

Balloon dilation of native CoA remains controversial and more information on its long-term impact is required.

METHODS

Hemodynamic, angiographic and follow-up data on 69 children who underwent balloon angioplasty of native CoA between 1988 and 1996 were reviewed. Stretch, recoil and gain of CoA circumference and area were calculated and related to outcomes.

RESULTS

Initial systolic gradients (mean +/- SD, 31+/-12 mm Hg) fell by -74+/-27% (p < 0.001), with an increase in mean CoA diameters of 128+/-128% in the left anterior oblique and 124+/-87% in the lateral views (p < 0.001). Two deaths occurred, one at the time of the procedure and one 23 months later, both as a result of an associated cardiomyopathy. Seven patients had residual gradients of >20 mm Hg. One patient developed an aneurysm, stable in follow-up, and four patients had mild dilation at the site of the angioplasty. Freedom from reintervention was 90% at one year and 87% at five years with follow-up ranging to 8.5 years. Factors significantly associated with decreased time to reintervention included: a higher gradient before dilation, a smaller percentage change in gradient after dilation, a small transverse arch and a greater stretch and gain, but not recoil.

CONCLUSION

Balloon dilation is a safe and efficient treatment of native CoA in children. Greater stretch and gain are factors significantly associated with reintervention, possibly related to altered elastic properties and vessel scarring.

Complications associated with pediatric cardiac catheterization

OBJECTIVES

The aim of this study was to determine the relative risks of pediatric diagnostic, interventional and electrophysiologic catheterizations.

BACKGROUND

The role of the pediatric catheterization laboratory has evolved in the last decade as a therapeutic modality, although remaining an important tool for anatomic and hemodynamic diagnosis.

METHODS

A study of 4,952 consecutive pediatric catheterization procedures was undertaken.

RESULTS

Patient ages ranged from 1 day to 20 years (median 2.9 years). One or more complications occurred in 436 studies (8.8%) and were classified as major in 102 and minor in 458, with vascular complications (n=189; 3.8% of procedures) the most common adverse event. Arrhythmic complications (n=24) were the most common major complication. Death occurred in seven cases (0.14%) as a direct complication of the procedure and was more common in infants (n=5). Independent risk factors for complications included a young patient age and undergoing an interventional procedure.

CONCLUSIONS

Complications continue to be associated with pediatric cardiac catheterization. Efforts should be directed to improving equipment for flexibility and size, and finding alternative methods for vascular access. Patient age and interventional studies are risk factors for morbidity and mortality.

Biomechanical and structural assessment of transluminal angioplasty

The increasing incidence of stroke is frequently maintained by the processes narrowing precerebral and cerebral arteries. That is why the surgical treatment of cerebrovascular disorders has increasingly included percutaneous transluminal angioplasty. However, the influence of transluminal angioplasty on the biomechanical properties of arterial wall have not been assessed so far. The cylindrical segments of left and right internal carotid artery, middle cerebral artery, anterior cerebral artery, vertebral artery, basilar artery and posterior cerebral artery were taken from 40 autopsy subjects aged from 20 to 75 who had no systemic lesions with the exception of atherosclerosis. The biomechanical examination and experimental transluminal angioplasty of the segments were carried out with special equipment developed for this purpose. The data were obtained using a TV camera assisted measurement and morphometric and histological methods. The examination of the biomechanical properties repeated after the experimental transluminal angioplasty shows the additional relative strain of the external diameter of vessel and the decrease of the arterial wall tangential elastic modulus in the circumferential direction. This suggests that if transluminal angioplasty results in sufficient structural damage of the arterial wall than there will be an improvement in the ability of the vessel diameter to increase under normal blood pressure conditions.

Transumbilical catheterization of cerebral arteries

OBJECTIVE AND IMPORTANCE

For neonates requiring cerebral endovascular procedures, an alternative route of arterial access, the umbilical artery, is described. Transfemoral catheterization, with its attendant risks, can thus be avoided.

CLINICAL PRESENTATION

Six neonates with severe cardiac failure secondary to aneurysmal malformations of the vein of Galen underwent transarterial embolization in an effort to reduce flow through the intracranial arteriovenous malformations and therefore improve control of the high output cardiac failure.

TECHNIQUE

The transumbilical route was used in each case, with successful devascularization of some of the malformations in all patients. The femoral arteries were preserved for future staged embolizations. No complications related to the umbilical artery catheterization were encountered.

CONCLUSION

Femoral artery cannulation in neonates is technically challenging and may result in stenosis or thrombosis of the vessel. The umbilical artery provides an alternative route of vascular access for cerebral artery catheterization and embolization in these patients, preserving the femoral arteries for future interventions.

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.

Acute results of balloon angioplasty of native coarctation versus recurrent aortic obstruction are equivalent. Valvuloplasty and Angioplasty of Congenital Anomalies (VACA) Registry Investigators

OBJECTIVES

This study sought to compare the immediate results and risk factors for suboptimal outcomes of percutaneous balloon angioplasty for native versus recurrent aortic obstruction.

BACKGROUND

Some cardiology centers have been reluctant to adopt balloon angioplasty for treatment of native aortic coarctation, while advocating balloon angioplasty over an operation for treatment of postsurgical or recurrent aortic obstruction.

METHODS

Acute results were analyzed from 970 procedures (422 native and 548 recurrent lesions) performed between 1982 and 1995 in 907 patients from 25 centers. An acute suboptimal outcome was defined as one or more of the following: residual systolic pressure gradient > or = 20 mm Hg, residual proximal to distal systolic pressure ration > or = 1.33 or a major complication (death, aortic transmural tear, stroke).

RESULTS

Bal loon angioplasty significantly (p = 0.0001) increased lesion diameter fo r both native (mean [+/= SD] 128 +/= 94%) and recurrent aortic obstruction (97 +/= 87%), with a significantly greater increase in the native group (p = 0.0001). A reduction in systolic pressure gradients was significant in both groups (p = 0.0001), but slightly higher (p = 0.01) for native (-74 +/- 24%) versus recurrent obstruction (-70 +/- 31%). Death associated with angioplasty was reported in 0.7% of patients with native and in 0.7% of patients with recurrent lesions (p = 1.00). An acute suboptimal outcome was noted with angioplasty in 19% of native and in 25% of recurrent lesions (p = 0.04). Significant independent risk factors included higher preangioplasty systolic gradient (odds ratio [OR] 1.39/10-mm Hg increment; 95% confidence interval [CI] 1.28 to 1.50, p = 0.0001), earlier study date (OR 0.92/1-year increment, 95% CI 1.02 to 1.26, p = 0.02) and recurrent obstruction (OR 1.39 vs. native lesions, 95% CI 1.00 to 1.94, p = 0.05).

CONCLUSIONS

Acute results and complications of balloon angioplasty of native coarctation appear to be equivalent or slightly superior to those of recurrent aortic obstructions.

Biomechanical effects of experimental transluminal angioplasty

Surgical treatment of vertebrobasilar circulation disorders includes percutaneous transluminal angioplasty more often recently. However, the biomechanical aspects of transluminal angioplasty have not been studied sufficiently so far. 148 left and right vertebral artery segments were taken from 24 autopsy subjects (14 male and 10 female) aged from 20 to 75, who had neither systemic nor cerebrovascular lesions. Biomechanical examination and experimental transluminal angioplasty (ETA) of the tubular segments of vertebral artery (VA) were carried out by the special equipment developed for this purpose. The data were obtained using telemetrical, morphometrical and hystological methods. The biomechanical properties taken in the conditioned physiological rate are different for each segment of the VA. The stiffness of VA wall increases with age (mainly after 40 years), particularly in segments V1 and V3. Nevertheless, after high intravascular pressure application the diameter response of VA to intravascular fluid pressure increases if sufficient structural damage of the arterial wall was made.

Paediatric cardiac catheterization: innovations

In recent years interventional procedures have been introduced to the field of paediatric cardiac catheterization. These procedures continue to develop in complexity and increasingly are being applied to patients with reduced cardiovascular reserve, as an alternative to cardiac surgery or when cardiac surgery with cardiopulmonary bypass is contraindicated. More frequently anaesthetists are being called upon to provide support in sedating, anaesthetizing or/and resuscitating these patients. The purpose of this review is to give a comprehensive update of the interventional procedures and to review the anaesthetic management techniques as they apply to the catheterization laboratory. We will discuss possible complications and management strategies from our own experience and the experience of others. We have observed that as more complicated procedures are performed the anaesthetist plays a pivotal role in the management of the patient from arrival to departure from the cardiac catheterization laboratory, and in preventing mortality and major morbidity. Although the economic consequences of interventional cardiological techniques remain unclear, the field continues to expand and more complex procedures are continually being introduced.