Transcatheter Ventricular Septal Defect Research Articles

TCTAP C-222 A Case of Transcatheter Ventricular Septal Defect Closure in a Challenging Pectus Excavatum Patient

TCTAP C-222 A Case of Transcatheter Ventricular Septal Defect Closure in a Challenging Pectus Excavatum Patient

Short Term Outcomes of Transcatheter Ventricular Septal Defect Device Closure at Tertiary Cardiac Care Center

Objective: To determine post procedural immediate and short-term outcomes of transcatheter Ventricular Septal Defect (VSD) device closure. Study Design: Longitudinal Cross-sectional study. Place and Duration of Study: Pediatric Cardiology Unit at Tertiary Cardiac Care Centre, Rawalpindi, Pakistan, from Feb to Oct 2022. Methodology: Total of 62 patients fulfilling inclusion and exclusion criteria who underwent transcatheter VSD device closure were retrospectively identified from our institutional database by non-probability consecutive sampling technique. Preprocedural evaluation [Transthoracic Echocardiography (TTE) & Electrocardiography(ECG)], procedural details and immediate post procedure outcomes were documented. Follow-up evaluations were done at 6 and 12 months. It included clinical examination, TTE and 12 lead ECG. New onset and status of old complications were documented in each visit. SPSS version 24.00 was used to analyze data. Chi-square test was used to find association between study variables. p-<0.05 wasconsidered significant. Results: Sixty-two patients were followed up for upto 1 year after VSD device closure. Mean VSD size on Echo was 4.612.52mm. Successful closure was obtained in 54(87.0%) of cases out of 62. Complications documented during and immediately after procedure were transient arrythmias in 22(35.5%), residual leaks in 9(14.6%) which reduced to 3(4.8%) on 12 months follow up, device redeployment in 3(4.8%), complete heart block (cAVB) in 1(1.6%), device embolization in 1(1.6%), hemolysis in 2(3.2%), contrast related complications in 1(1.6%), aortic regurgitation (AR) in 4(6.4%). Death occurred in 1(1.6%) patient secondary to contrast related complications. Conclusion: Transcatheter VSD closure is a promising and safe treatment modality with high success rate. Complications ..

Transcatheter Ventricular Septal Defect Closure with Lifetech™ Konar-MF Occluder in Infants Under 10kg with Only Using Venous Access.

Transcatheter closure of VSD remains a complex procedure in infants with technical challenges and carries the risk of significant complications, due to its complex anatomical morphology and closed proximity to the atrioventricular valves and the conduction system. In this article, we presented transcatheter VSD closure in infants under 10kg using the Lifetech Konar-MF device via only venous route without TEE guidance and arterial access. Between January 2021 and May 2023, a total of 34 patients weighing less than 10kg who underwent transcatheter VSD closure antegradely with Lifetech™ Konar-Multifunctional (MF) occluder were included in the study. The mean age of the patients was 8.1 (3.5-35) months. Average weight was 6.5kg (range 4.5-10kg). VSD was perimembranous in 27 patients (79.4%). Successful device placement was achieved in all 34 patients. However, device embolization occurred in three patients. One of the patients was successfully implanted with a one size larger device, the surgical closure was performed other two cases. TR occurred in seven patients (20.6%) after releasing devices. None of the patients developed complete heart block. Right bundle branch block developed in two patients. Residual shunt was observed in 9 patients (six small, two moderate, and one large). During follow-up, residual shunt disappeared in six of these patients and only mild residual shunt remained in the other four patients which have not required any further intervention. Transcatheter closure of VSD with Lifetech Konar-MF device is safe and effective in infants less than 10kg via only venous access with a high success rate and low complication rate. In these patients, transcatheter VSD closure can be performed by excluding the risk of complications that may occur due to AV loop formation, arterial intervention, endotracheal intubation and TEE use.

Closure of transcatheter ventricular septal defect using LifetechTM Konar-MF Occluder in children weighing less than 10 kilograms: mid-term results, a tertiary single center experience.

Transcatheter closure of medium and large ventricular septal defects (VSDs) in young children is limited due to the use of over-sized devices that can cause hemodynamic instability and arrhythmia. In this study, we aimed to retrospectively evaluate the safety and efficacy of the device in the mid-term in children weighing less than 10 kg whose transcatheter VSD was closed only with the Konar-MFO device. Among 70 children whose transcatheter VSD was closed between January 2018 and January 2023, 23 patients weighing less than 10 kg were included in the study. Retrospectively, the medical records of all patients were reviewed. The mean age of the patients was 7.3 (4.5-26) months. 17 of the patients were females, 6 of them were males, F/M: 2.83. The average weight was 6.1 (3.7-9.9) kg. The mean the pulmonary blood flow/ systemic blood flow (Qp/Qs) was 3.3 (1.7-5.5). The mean defect diameter was 7.8 mm (5.7-11) for the left ventricle (LV) side, and 5.7 mm (3-9.3) for the right ventricle (RV) side. Based on the utilized device dimensions, the measurements on the LV side were recorded as 8.6 mm (range 6-12), while those on the RV side were recorded as 6.6 mm (range 4-10). Antegrade technique was applied to 15 (65.2%) patients and retrograde technique was applied to 8 (34.8%) patients in the closure procedure. The procedure success rate was 100%. The incidence of death, device embolization, hemolysis, or infective endocarditis was zero. Perimembranous and muscular VSDs in children under 10 kg can be successfully closed under the management of an experienced operator with the Lifetech Konar-MFO device. This is the first study in the literature to evaluate the efficacy and safety of the device in children under 10 kg in whom only Konar-MFO VSD occluder device is used for transcatheter VSD closure.

Transcatheter Ventricular Septal Defect Closure with Nit-Occlud Lê VSD Device—Five Years’ Experience and Literature Review

Transcatheter Ventricular Septal Defect Closure with Nit-Occlud Lê VSD Device—Five Years’ Experience and Literature Review

A fully degradable transcatheter ventricular septal defect occluder: Towards rapid occlusion and post-regeneration absorption

Degradable heart occluders are a promising replacement for currently clinically used non-degradable ones without concerns about the complications caused by the persistent residue of a foreign implant. However, the inherent mechanical properties of degradable occluders are poor and decline with material degradation, leading to a preference for a long degradation period upon designing a degradable heart occluder. This configuration can lower the risk of occluder dislodgement but reduce the benefits of degradable implants over their non-degradable counterparts due to a longer retention of foreign materials in the human body. Here, we fabricated a fully degradable ventricular septum defect (VSD) occluder consisting of polydioxanone (PDO) fiber and poly-L-lactic acid (PLLA) membrane featuring an auto-locking function. The degradable occluder showed an excellent shape recovery effect after transcatheter delivery and anchored securely to a heart defect as evidenced by in vitro and in vivo experiments. The degradable occluder could warrant robust fixation ability during the first 3-months of implantation within which tissue reconstruction was accomplished and be completely absorbed within 12 months. Benefitting from these merits, the degradable occluder displayed desired occlusion and no complications after being implanted in the VSD sites of canines during a 24-months follow-up. Compared with traditional non-degradable occluders, our degradable occluder could provide a potentially superior approach for rapidly repairing the congenital VSD without interfering with the normal development and physiological function of the heart.

Long-Term Follow-up of Transcatheter Ventricular Septal Defect Closure in Children, and Comparison of Single-Hole Versus Multi-holes Ventricular Septal Defects

Background: Evaluation of complications after transcatheter ventricular septal defect (VSD) closure in long-term follow-up and large samples of children is limited. Objectives: We compared the residual shunt after transcatheter closure in VSDs with a single hole and multiple holes, a new task that has not been done so far. Methods: This retrospective study included all patients who underwent transcatheter device closure for VSD in a tertiary cardiovascular center from 2009 to 2020. Follow-up evaluation using transthoracic echocardiography (TTE) and electrocardiogram (ECG) was performed at 1, 6, 12 months, and annually after the procedure. Results: A total of 409 patients underwent transcatheter VSD closure. The mean age was 7 years (2 - 15 years), and the median follow-up duration was 48 months (1 - 10 years). The number of patients with a singular VSD was 259 (63.4%), and those with multiple exit holes were 150 (36.6%). The incidence of a residual shunt immediately after implantation was significantly higher in VSDs with multiple holes than those with a single hole (P = 0.008). During the follow-up, the residual shunts decreased in the group of VSDs with a single hole. Forty-five patients (11%) and 16 patients (4%) had a new-onset of mild and moderate tricuspid regurgitation (TR), respectively, and it decreased dramatically over time. Only 1 patient showed a new-onset mild aortic regurgitation (AR). The most crucial complication shown in 2 patients was a persistent complete heart block. Conclusions: Ventricular septal defects with multiple exit holes are a risk factor for a residual shunt. After transcatheter VSD closure, the residual shunt in patients with a multiple-hole VSD was significantly higher (P = 0.008). Although TR may increase during the procedure, it decreases dramatically over time. Interestingly, patients who had pre-procedure tricuspid or aortic regurgitation disappeared after 2 years of the procedure. The most important complication was a complete heart block in 2 patients.

Does transcatheter ventricular septal defect closure affect heart rate variability in children?

BackgroundHeart rate variability (HRV) is a sign of the cardiac autonomic nervous system. Its evaluation in pediatric ventricular septal defect (VSD) cases before and after transcatheter closure contributes to an understanding of cardiac autonomic control. MethodsNineteen children with VSDs treated with transcatheter closure and 18 healthy children were enrolled in this study. A 24-h Holter rhythm monitor was applied to all patients before VSD closure and to those in the control group. Holter rhythm monitoring was repeated at three months in the patient group. HRV parameters were measured using the Cardio Scan Premier 12® program. Frequency-domain (total power; very-low-frequency, low-frequency (LF), and high-frequency (HF) indices; and the LF/HF ratio) and time-domain (standard deviation of all RR intervals (SDNN), standard deviation of 5-min averages of RR intervals (SDANN), the SDNN index, percentage of the difference between adjacent RR intervals, and the square root of the mean of the sum of square differences between adjacent filtered RR intervals) parameters were assessed. ResultsBefore the procedure, SDNN, SDANN, and total power values were lower in the patient group than in the control group; other parameters were similar in the two groups. No significant difference in the SDNN, SDANN, or total power was detected between the patient and control groups in the third month, indicating that autonomic control of patients’ hearts became normal during the third postoperative month. No correlation was detected between any hemodynamic parameters and any time-domain or frequency-domain parameters before closure. ConclusionThis study showed that transcatheter closure of VSDs changed HRV parameters in pediatric patients.

Experiences of Two Centers in Percutaneous Ventricular Septal Defect Closure Using Konar Multifunctional Occluder.

BackgroundTranscatheter closure of perimembraneous ventricular septal defect still poses a challenge due to the adjacent structures of the tricuspid and aortic valves and the risk of atrioventricular block. We report our experience at 2 centers using the KONAR-MF (multifunctional occluder) ventricular septal defect device, which gained its CE mark in May 2018.Methods A retrospective study was carried out on all patients who underwent transcatheter ventricular septal defect closure with the KONAR-MF (multifunctional occluder) ventricular septal defect device at 2 centers.Results A total of 47 patients were identified. The median age and weight of the patients were 25.8 months and 11 kg. The ventricular septal defects that were closed in 5 cases were post-operative hemodynamically significant residual ventricular septal defects. Forty-eight devices were used in the 47 cases. As for the location of the ventricular septal defect, 40/48 (83.33%) ventricular septal defects were perimembranous and 8/48 (16.66%) were muscular. The percutaneous device closure was successful in 46 procedures (95.8%). Device embolization was observed in 2 patients, and a significant residual shunt was observed in 2 cases. In the follow-up, there was no enhancement in the residual shunt in the remaining cases. Temporary atrioventricular block occurred in 2 cases during the procedure and improved after long sheath withdrawal.Conclusion Soft, flexible, and low-profile KONAR-MF (multifunctional occluder) occluders ensure easy and safe implantation, and small sheath sizes allow for their use in small infants. Although near and mid-term follow-ups did not indicate any permanent atrioventricular block, a larger sample of patients and a longer follow-up period is necessary to understand long-term outcomes.

The Effect of Transcatheter Ventricular Septal Defect Closure on Children's Appetite, Hormones and Growth

The Effect of Transcatheter Ventricular Septal Defect Closure on Children's Appetite, Hormones and Growth

Clinical Experience of Transcatheter Closure for Ventricular Septal Defects in Children Weighing under 15 kg.

Failure to thrive and poor weight gain are the main problems associated with ventricular septal defects complicated by heart failure in pediatric patients. Recent advances in transcatheter closure have enabled safe and effective interventions in these patients. The purpose of this study was to describe our experience with transcatheter closure of ventricular septal defects in young children with low weight. Pediatric patients weighing < 15 kg who underwent transcatheter closure of ventricular septal defects between January 2018 and December 2019 at our hospital were retrospectively enrolled. Twelve patients were enrolled: one with a muscular defect, two with outlet defects, and nine with perimembranous defects. Their median age was 24 (7-60) months, and their median weight before the procedure was 11.8 kg (4.7-14.9 kg; mean Z-score: -1.3). The median precordial echocardiographic defect diameter was 5.6 (2.0-9.3) mm. Successful transcatheter closure was achieved in 11 cases. The mean weight at 1-month follow-up after defect closure was 13.5 kg (6.2-19.8 kg; mean Z-score: -0.2). The mean length of hospitalization was 2.7 days. This study highlights the potential safety and therapeutic efficacy of transcatheter ventricular septal defect closure in infants with low weight. Considerable weight gain and heart failure symptom attenuation at 1 month after transcatheter closure were observed.

Percutaneous closure of ventricular septal defect using LifeTechTM Konar-MF VSD Occluder: initial and short-term multi-institutional results.

Transcatheter ventricular septal defect closure remains a complex procedure with potential complications like complete heart block and aortic regurgitation. The ideal device design for such intervention is still evolving. To assess the safety, efficacy, and short-term outcome of ventricular septal defect closure using LifeTechTM multifunctional (KONAR-MFTM) VSD Occluder. In a multicenre study, 44 patients with haemodynamically significant, restrictive ventricular septal defects underwent closure with the KONAR-MFTM device from April, 2019 to March, 2020. Clinical, echocardiographic, and angiographic data were collected and reviewed. Patients were followed up at 1, 3, 6, and 12 months. The median age and weight were 8 (1.7-36) years and 20 (11-79) kg. Of 44 patients, 8 (18%) had a high muscular and 36 (82%) had a perimembranous defect, of which 6 had mild prolapse of the right coronary cusp. The median ventricular septal defect size was 8.8 (3.9-13.4) mm. A retrograde approach was adopted in 39 (88.6%) patients. Nine patients (20.5%) had a small residual leak and there was a slight increase in aortic regurgitation in one patient. One device, which embolised to pulmonary artery was retrieved, and the defect was closed with a larger device. At a median follow-up of 13 (5-18) months, the residual leak persisted in 1 (2.3%) patient. Mild aortic regurgitation in one patient remained unchanged. There were no major complications. Percutaneous closure of ventricular septal defect using KONAR-MFTM device is safe and effective in short and midterm follow-up including selected patients with perimembranous defect and mild prolapse of the right coronary cusp.

Radiation dose typical values per procedure complexity for transcatheter ventricular septal defect closure in pediatrics

This study aims to establish radiation dose typical values (TV) for ventricular septal defect (VSD) percutaneous closures based on patient-, device- and procedure-related characteristics. Clinical and exposure data were retrospectively reviewed for 92 consecutive pediatric patients with VSD in whom transcatheter closure attempt was undertaken between March 2016 and December 2019 at a single reference center. TV were derived as the median value of total air kerma-area product (PKA,T), air kerma at the patient entrance reference point, fluoroscopy time and number of frames. Statistical analyses were conducted to investigate the exposure variability according to patient, device- and procedure-related characteristics. For (5–&lt; 15 kg) patients, TV were 27 Gy · cm2 in term of PKA,T for venous vs. 9 Gy · cm2 for arterial approach. For (15–&lt; 30 kg) patients, TV were 53 Gy · cm2 for muscular vs. 18 Gy · cm2 for perimembranous defects and 36 Gy · cm2 for AmplatzerTM vs. 14 Gy · cm2 for the LifetechTM device. Procedures conducted with the assistance of a fellow, venous approach, muscular VSD, AmplatzerTM devices, and procedural incidents increased the exposure levels significantly. The established TV provide benchmarks on patient exposure per procedure complexity and should help promote better patient radiation protection.

Efficacy and Safety of Transcatheter Ventricular Septal Defect Closure Using Nit-Occlud Le VSD coil in Short-term Observation

Nit-Occlud Le VSD coil, an alternative device for closing VSD transcatheter, started to be used in dr. Soetomo Hosptal in 2017, but no research has been done on the results of closure with this device. This study aims to evaluate the efficacy and safety of the Nit-Occlud Le VSD coil. Descriptive observational method was used. The results are as follow: Of the 17 patients who underwent transcatheter closure during January to December 2018, 10 (58, 8%) cases were closed with Nit- Occlud Le VSD coil. The success of implantation is 100%, 8 cases were closed with Nit-Occlud Le VSD coil, 2 plus an amplatzer (ADO 1 and AVSO). Type of VSD: perimembranaous 7 (70%), subaortic 2 (20%) and mid muscularis 1 (10%). Immediate complete closure in 7/10 (70%), while 3 (30%) obtained residual DSV. The closure rate at the first month of follow up becomes 80%. Median length of post-catheterization was 2 days (2 - 3 days). Complications: 1 (10%) mild aortic regurgitation, 1 (10%) hemolysis and 2 (20%) with additional second device (ADO 1 and AVSO): first case: moderate residual VSD and severe aortic regurgitation; second case: severe tricuspid regurgitation and residual VSD that disappeared in first month. The residual VSD altered from 30% to 10%, and closure rate was 80% at the first month of observation. VSD closure with Nit-Occlud Le VSD coil provides good efficacy and safety for patients.&#x0D; Keywords: VSD, Nit-Occlud Le VSD coil.

Comparison of Long-Term Complications of Using Amplatzer Ductal Occluder and Ventricular Septal Defect Occluder for Transcatheter Ventricular Septal Defect Closure.

Background:Ventricular Septal Defect (VSD) is the most common type of congenital heart disease and perimembranous type is the commonest form of these defects. Trans-catheter management of these defects is a challenging procedure.Objectives:The purpose of this study was to compare of Trans-catheter closure of perimembranous ventricular septal defect (PMVSD) using Amplatzer Ductal Occluder (ADO) and VSD occluder and their complications and follow-up.Patients and Methods:Between 2013 and April 2019, 69 patients underwent percutaneous closure of PMVSD using ADO (29 patients) and VSD occluder (40 patients). After obtaining the size of VSD from the ventriculogram at least 2 mm larger than the orifice diameter of VSD at the right ventricular side was chosen. The devices were positioned after verification of the proper device position by echocardiography, aortogram and left ventriculography.Results:The mean age of patients were 9.07 ± 7.73 years, mean weight 26.12 ±16.25 kg. The mean defect size of the right ventricular orifice and device sizes were 5.54 ± 1.83 mm 7.72 ± 1.94 mm respectively.Small residual shunts were seen at the completion of the procedure, but they disappeared during follow-up in all but one patient. Two patients had mild AI before the procedure in ADO group that disappeared during the follow-up. The mean follow-up period was 3.3 ± 1.7 years (range 1 to 6 years). Complete atrioventricular block (CAVB) was seen in one patient (VSD occluder) during the procedure that disappeared after the retrieval of the device. Major complication or death was not observed in our study.Conclusions:Trans-catheter closures of PMVSD with ADO or VSD occluder had similar effects in these patients and are safe and effective treatment associated with excellent success and closure rates. Long-term follow-up in a large number of patients is warranted.

Exercise Capacity and Ventricular Remodeling After Transcatheter Ventricular Septal Defect Closure in Asymptomatic or Minimally Symptomatic Adolescents and Adults.

Transcatheter ventricular septal defect (VSD) closure is a safe and efficacious alternative to surgery. However, its benefits in asymptomatic or minimally symptomatic patients remain unknown. Sixty patients with VSD aged 12 to 60 years underwent cardiopulmonary exercise test and echocardiography 1 day before transcatheter VSD closure and 6 months after intervention (closure group). Thirty patients who did not receive the intervention underwent the same evaluations over 6 months (observation group). No significant change in exercise function was observed after VSD closure, except for increased peak oxygen (O2) pulse (absolute increase: 0.4±1.4 mL/beat). Left ventricular end-diastolic dimension and mitral peak early filling velocity-to-early diastolic annular velocity ratio decreased (absolute decrease: 0.3±0.6 cm and 0.7±1.9, respectively). Despite unchanged overall peak O2 consumption, 33% of closure group patients exhibited clinically significant improvements in peak O2 consumption (>10% increase relative to baseline). This was not related to the pulmonary flow-to-systemic flow ratio or baseline exercise capacity. By contrast, all exercise function parameters deteriorated significantly in the observation group. Subgroup analysis revealed that patients with a baseline left ventricular end-diastolic dimension Z score of >2 exhibited a significantly greater improvement in peak O2 consumption, peak O2 pulse, and oxygen uptake efficiency slope than did the observation group. Compared with conservative management, transcatheter VSD closure prevents deterioration in exercise capacity and promotes left ventricular reverse remodeling in asymptomatic or minimally symptomatic patients. These benefits are most prominent in patients whose left ventricular end-diastolic dimension Z score before intervention is >2, irrespective of baseline peak O2 consumption and pulmonary flow/systemic flow ratio. Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT03127748.

Directly ventricular septal defect closure without using arteriovenous wire loop: Our adult case series using transarterial retrograde approach.

Objective:The standard transcatheter ventricular septal defects (VSD) closure procedure is established with arteriovenous (AV) loop and is called as antegrade approach. The directly retrograde transarterial VSD closure without using AV loop might be better option as shortens the procedure time and decreases radiation exposure.Methods:Our series consist of twelve sequential adult cases with congenital VSDs (seven with perimembranous, four with muscular, one with postoperative residuel VSD). The mean age was 26.9 (Range 18–58), the mean height was 168.75 cm (Range 155–185cm), and the mean body mass index was 23.4 (Range 17.3–28.4). Maximum and minimum defect sizes were 10 and 5 mm and the mean defect size was 6.24 mm. The procedure was performed with left heart catheterization and advancing the delivery sheath over the stiff exchange wire then VSD occlusion from left side.Results:The defects were successfully closed with this technique in eleven patients. In sixth patient, the defect could not be cannulated by the delivery sheath, as the tip of the sheath did not reach the defect and VSD was closed with same sheath by standard transvenous approach using AV loop. We didn’t encounter any complication releated to semilunar or atrioventricular valves. Atrioventricular conduction system was not affected by the procedure in any patients. The median procedure and fluoroscopy times were 66 and 16.5 minutes respectively.Conclusion:Transarterial retrograde VSD closure without using AV loop simplifies the procedure, decreases the radiation exposure, and shortens the procedure time. The only limitation in adult patients is delivery sheath length.

Management of intractable hemolysis after transcatheter ventricular septal defect closure with Nit Occlud® Lê ventricular septal defect coil

Management of intractable hemolysis after transcatheter ventricular septal defect closure with Nit Occlud® Lê ventricular septal defect coil

Transcatheter ventricular septal defect closure – A tertiary care center experience from South India

Transcatheter ventricular septal defect closure – A tertiary care center experience from South India

Transcatheter Closure of Perimembranous Ventricular Septal Defects using Nit-Occlud® Lê VSD Coil: Early and Mid-Term Results

Our objective was to investigate the short- and mid-term results of transcatheter ventricular septal defect (VSD) closure with the Nit-Occlud(®) Lê VSD coil. Retrospective data collection study. Data were collected from 20 patients who underwent transcatheter VSD closure with the Nit-Occlud(®) Lê VSD coil device between October 2011 and June 2013. The mean age of the study subjects was 7.3 ± 4.0 years, and the mean weight was 25.7 ± 11.8 kg. The distance between the defect and the aortic valve, measured using angiography, was an average of 5.1 ± 2.0 mm, and the left ventricular opening averaged 8.2 ± 2.1 mm. The mean value of the Q p/Q s ratio was 1.7 ± 0.4. Intravascular hemolysis developed in the first few hours after the procedure in three patients. In one of these cases, despite medical treatment and the implantation of a detachable coil placed into the Nit-Occlud(®) device transcatheterly, hemolysis persisted. This device was removed and the VSD was closed surgically. In the other two cases, although the residual shunt persisted on echocardiography, the hemolysis regressed spontaneously. There were no rhythm problems or other complications during the follow-up period of 12.3 ± 6.6 months. In the selected cases, for the transcatheter treatment of VSD, the Nit-Occlud(®) Lê VSD coil device can be used. When compared with other VSD closure devices, there was no development of a permanent atrioventricular block, which is an important advantage. However, patients with a residual shunt should be monitored closely for the development of hemolysis during the first few hours.