Self-Expanding or Balloon-Expandable TAVR in Patients with a Small Aortic Annulus

BACKGROUND

Patients with severe aortic stenosis and a small aortic annulus are at risk for impaired valvular hemodynamic performance and associated adverse cardiovascular clinical outcomes after transcatheter aortic-valve replacement (TAVR).

METHODS

We randomly assigned patients with symptomatic severe aortic stenosis and an aortic-valve annulus area of 430 mm2 or less in a 1:1 ratio to undergo TAVR with either a self-expanding supraannular valve or a balloon-expandable valve. The coprimary end points, each assessed through 12 months, were a composite of death, disabling stroke, or rehospitalization for heart failure (tested for noninferiority) and a composite end point measuring bioprosthetic-valve dysfunction (tested for superiority).

RESULTS

A total of 716 patients were treated at 83 sites in 13 countries (mean age, 80 years; 87% women; mean Society of Thoracic Surgeons Predicted Risk of Mortality, 3.3%). The Kaplan-Meier estimate of the percentage of patients who died, had a disabling stroke, or were rehospitalized for heart failure through 12 months was 9.4% with the self-expanding valve and 10.6% with the balloon-expandable valve (difference, -1.2 percentage points; 90% confidence interval [CI], -4.9 to 2.5; P<0.001 for noninferiority). The Kaplan-Meier estimate of the percentage of patients with bioprosthetic-valve dysfunction through 12 months was 9.4% with the self-expanding valve and 41.6% with the balloon-expandable valve (difference, -32.2 percentage points; 95% CI, -38.7 to -25.6; P<0.001 for superiority). The aortic-valve mean gradient at 12 months was 7.7 mm Hg with the self-expanding valve and 15.7 mm Hg with the balloon-expandable valve, and the corresponding values for additional secondary end points through 12 months were as follows: mean effective orifice area, 1.99 cm2 and 1.50 cm2; percentage of patients with hemodynamic structural valve dysfunction, 3.5% and 32.8%; and percentage of women with bioprosthetic-valve dysfunction, 10.2% and 43.3% (all P<0.001). Moderate or severe prosthesis-patient mismatch at 30 days was found in 11.2% of the patients in the self-expanding valve group and 35.3% of those in the balloon-expandable valve group (P<0.001). Major safety end points appeared to be similar in the two groups.

CONCLUSIONS

Among patients with severe aortic stenosis and a small aortic annulus who underwent TAVR, a self-expanding supraannular valve was noninferior to a balloon-expandable valve with respect to clinical outcomes and was superior with respect to bioprosthetic-valve dysfunction through 12 months. (Funded by Medtronic; SMART ClinicalTrials.gov number, NCT04722250.).

Explant vs Redo-TAVR After Transcatheter Valve Failure: Mid-Term Outcomes From the EXPLANTORREDO-TAVR International Registry

BACKGROUND

Valve reintervention after transcatheter aortic valve replacement (TAVR) failure has not been studied in detail.

OBJECTIVES

The authors sought to determine outcomes of TAVR surgical explantation (TAVR-explant) vs redo-TAVR because they are largely unknown.

METHODS

From May 2009 to February 2022, 396 patients in the international EXPLANTORREDO-TAVR registry underwent TAVR-explant (181, 46.4%) or redo-TAVR (215, 54.3%) for transcatheter heart valve (THV) failure during a separate admission from the initial TAVR. Outcomes were reported at 30 days and 1 year.

RESULTS

The incidence of reintervention after THV failure was 0.59% with increasing volume during the study period. Median time from index-TAVR to reintervention was shorter in TAVR-explant vs redo-TAVR (17.6 months [IQR: 5.0-40.7 months] vs 45.7 months [IQR: 10.6-75.6 months]; P < 0.001], respectively. TAVR-explant had more prosthesis-patient mismatch (17.1% vs 0.5%; P < 0.001) as the indication for reintervention, whereas redo-TAVR had more structural valve degeneration (63.7% vs 51.9%; P = 0.023), with a similar incidence of ≥moderate paravalvular leak between groups (28.7% vs 32.8% in redo-TAVR; P = 0.44). There was a similar proportion of balloon-expandable THV failures (39.8% TAVR-explant vs 40.5% redo-TAVR; P = 0.92). Median follow-up was 11.3 (IQR: 1.6-27.1 months) after reintervention. Compared with redo-TAVR, TAVR-explant had higher mortality at 30 days (13.6% vs 3.4%; P < 0.001) and 1 year (32.4% vs 15.4%; P = 0.001), with similar stroke rates between groups. On landmark analysis, mortality was similar between groups after 30 days (P = 0.91).

CONCLUSIONS

In this first report of the EXPLANTORREDO-TAVR global registry, TAVR-explant had a shorter median time to reintervention, with less structural valve degeneration, more prosthesis-patient mismatch, and similar paravalvular leak rates compared with redo-TAVR. TAVR-explant had higher mortality at 30 days and 1 year, but similar rates on landmark analysis after 30 days.

Clinical Impact of Standardized TAVR Technique and Care Pathway: Insights From the Optimize PRO Study

BACKGROUND

Procedural success and clinical outcomes after transcatheter aortic valve replacement (TAVR) have improved, but residual aortic regurgitation (AR) and new permanent pacemaker implantation (PPI) rates remain variable because of a lack of uniform periprocedural management and implantation.

OBJECTIVES

The Optimize PRO study evaluates valve performance and procedural outcomes using an "optimized" TAVR care pathway and the cusp overlap technique (COT) in patients receiving the Evolut PRO/PRO+ (Medtronic) self-expanding valves.

METHODS

Optimize PRO, a nonrandomized, prospective, postmarket study conducted in the United States, Canada, Europe, Middle East, and Australia, is enrolling patients with severe symptomatic aortic stenosis and no pre-existing pacemaker. Sites follow a standardized TAVR care pathway, including early discharge and a conduction disturbance management algorithm, and transfemoral deployment using the COT.

RESULTS

A total of 400 attempted implants from the United States and Canada comprised the main cohort of this second interim analysis. The mean age was 78.7 ± 6.6 years, and the mean Society of Thoracic Surgeons predictive risk of mortality was 3.0 ± 2.4. The median length of stay was 1 day. There were no instances of moderate or severe AR at discharge. At 30 days, all-cause mortality or stroke was 3.8%, all-cause mortality was 0.8%, disabling stroke was 0.7%, hospital readmission was 10.1%, and cardiovascular rehospitalization was 6.1%. The new PPI rate was 9.8%, 5.8% with 4-step COT compliance. In the multivariable model, right bundle branch block and the depth of the implant increased the risk of PPI, whereas using the 4-step COT lowered 30-day PPI.

CONCLUSIONS

The use of the TAVR care pathway and COT resulted in favorable clinical outcomes with no moderate or severe AR and low PPI rates at 30 days while facilitating early discharge and reproducible outcomes across various sites and operators. (Optimize PRO; NCT04091048).

Structural Valve Deterioration After Self-Expanding Transcatheter or Surgical Aortic Valve Implantation in Patients at Intermediate or High Risk

Importance

The frequency and clinical importance of structural valve deterioration (SVD) in patients undergoing self-expanding transcatheter aortic valve implantation (TAVI) or surgery is poorly understood.

Objective

To evaluate the 5-year incidence, clinical outcomes, and predictors of hemodynamic SVD in patients undergoing self-expanding TAVI or surgery.

Design, Setting, and Participants

This post hoc analysis pooled data from the CoreValve US High Risk Pivotal (n = 615) and SURTAVI (n = 1484) randomized clinical trials (RCTs); it was supplemented by the CoreValve Extreme Risk Pivotal trial (n = 485) and CoreValve Continued Access Study (n = 2178). Patients with severe aortic valve stenosis deemed to be at intermediate or increased risk of 30-day surgical mortality were included. Data were collected from December 2010 to June 2016, and data were analyzed from December 2021 to October 2022.

Interventions

Patients were randomized to self-expanding TAVI or surgery in the RCTs or underwent self-expanding TAVI for clinical indications in the nonrandomized studies.

Main Outcomes and Measures

The primary end point was the incidence of SVD through 5 years (from the RCTs). Factors associated with SVD and its association with clinical outcomes were evaluated for the pooled RCT and non-RCT population. SVD was defined as (1) an increase in mean gradient of 10 mm Hg or greater from discharge or at 30 days to last echocardiography with a final mean gradient of 20 mm Hg or greater or (2) new-onset moderate or severe intraprosthetic aortic regurgitation or an increase of 1 grade or more.

Results

Of 4762 included patients, 2605 (54.7%) were male, and the mean (SD) age was 82.1 (7.4) years. A total of 2099 RCT patients, including 1128 who received TAVI and 971 who received surgery, and 2663 non-RCT patients who received TAVI were included. The cumulative incidence of SVD treating death as a competing risk was lower in patients undergoing TAVI than surgery (TAVI, 2.20%; surgery, 4.38%; hazard ratio [HR], 0.46; 95% CI, 0.27-0.78; P = .004). This lower risk was most pronounced in patients with smaller annuli (23 mm diameter or smaller; TAVI, 1.32%; surgery, 5.84%; HR, 0.21; 95% CI, 0.06-0.73; P = .02). SVD was associated with increased 5-year all-cause mortality (HR, 2.03; 95% CI, 1.46-2.82; P < .001), cardiovascular mortality (HR, 1.86; 95% CI, 1.20-2.90; P = .006), and valve disease or worsening heart failure hospitalizations (HR, 2.17; 95% CI, 1.23-3.84; P = .008). Predictors of SVD were developed from multivariate analysis.

Conclusions and Relevance

This study found a lower rate of SVD in patients undergoing self-expanding TAVI vs surgery at 5 years. Doppler echocardiography was a valuable tool to detect SVD, which was associated with worse clinical outcomes.

Trial Registration

ClinicalTrials.gov Identifiers: NCT01240902, NCT01586910, and NCT01531374.

2-Year Outcomes After Transcatheter Versus Surgical Aortic Valve Replacement in Low-Risk Patients

BACKGROUND

The Evolut Low Risk Trial (Medtronic Evolut Transcatheter Aortic Valve Replacement in Low Risk Patients) showed that transcatheter aortic valve replacement (TAVR) with a supra-annular, self-expanding valve was noninferior to surgery for the primary endpoint of all-cause mortality or disabling stroke at 2 years. This finding was based on a Bayesian analysis performed after 850 patients had reached 1 year of follow-up.

OBJECTIVES

The goal of this study was to report the full 2-year clinical and echocardiographic outcomes for patients enrolled in the Evolut Low Risk Trial.

METHODS

A total of 1,414 low-surgical risk patients with severe aortic stenosis were randomized to receive TAVR or surgical AVR. An independent clinical events committee adjudicated adverse events, and a central echocardiographic core laboratory assessed hemodynamic endpoints.

RESULTS

An attempted implant was performed in 730 TAVR and 684 surgical patients from March 2016 to May 2019. The Kaplan-Meier rates for the complete 2-year primary endpoint of death or disabling stroke were 4.3% in the TAVR group and 6.3% in the surgery group (P = 0.084). These rates were comparable to the interim Bayesian rates of 5.3% with TAVR and 6.7% with surgery (difference: -1.4%; 95% Bayesian credible interval: -4.9% to 2.1%). All-cause mortality rates were 3.5% vs 4.4% (P = 0.366), and disabling stroke rates were 1.5% vs 2.7% (P = 0.119), respectively. Between years 1 and 2, there was no convergence of the primary outcome curves.

CONCLUSIONS

The complete 2-year follow-up from the Evolut Low Risk Trial found that TAVR is noninferior to surgery for the primary endpoint of all-cause mortality or disabling stroke, with event rates that were slightly better than those predicted by using the Bayesian analysis. (Medtronic Evolut Transcatheter Aortic Valve Replacement in Low Risk Patients [Evolut Low Risk Trial]; NCT02701283).

Two-Year Outcomes After Transcatheter Aortic Valve Replacement With Mechanical vs Self-expanding Valves: The REPRISE III Randomized Clinical Trial

Importance

To our knowledge, REPRISE III is the first large randomized comparison of 2 different transcatheter aortic valve replacement platforms: the mechanically expanded Lotus valve (Boston Scientific) and self-expanding CoreValve (Medtronic).

Objective

To evaluate outcomes of Lotus vs CoreValve after 2 years.

Design, Setting, and Participants

A total of 912 patients with high/extreme risk and severe, symptomatic aortic stenosis enrolled between September 22, 2014, and December 24, 2015, were randomized 2:1 to receive Lotus (607 [66.6%]) or CoreValve (305 [33.4%] at 55 centers in North America, Europe, and Australia. The first 2-year visit occurred on October 17, 2016, and the last was conducted on April 12, 2018. Clinical and echocardiographic assessments are complete through 2 years and will continue annually through 5 years.

Main Outcomes and Measures

All-cause mortality and all-cause mortality or disabling stroke at 2 years. Other clinical factors included overall stroke, disabling stroke, repeated procedures, rehospitalization, valve thrombosis, and pacemaker implantation. Echocardiographic analyses included effective orifice area, mean gradient, and paravalvular leaks (PVLs).

Results

Of 912 participants, the mean (SD) age was 82.8 (7.3) years, 465 (51%) were women, and the mean (SD) Society of Thoracic Surgeons predicted risk of mortality was 6.8% (4.0%). At 2 years, all-cause death was 21.3% with Lotus vs 22.5% with CoreValve (hazard ratio [HR], 0.94; 95% CI, 0.69-1.26; P = .67) and all-cause mortality or disabling stroke was 22.8% with Lotus and 27.0% with CoreValve (HR, 0.81; 95% CI, 0.61-1.07; P = .14). Overall stroke was 8.4% vs 11.4% (HR, 0.75; 95% CI, 0.48-1.17; P = .21); disabling stroke was more frequent with CoreValve vs Lotus (4.7% Lotus vs 8.6% CoreValve; HR, 0.53; 95% CI, 0.31-0.93; P = .02). More Lotus patients received a new permanent pacemaker (41.7% vs 26.1%; HR, 1.87; 95% CI, 1.41-2.49; P < .01) or had a valve thrombosis (3.0% vs 0.0%; P < .01) compared with CoreValve. More patients who received CoreValve experienced a repeated procedure (0.6% Lotus vs 2.9% CoreValve; HR, 0.19; 95% CI, 0.05-0.70; P < .01), valve migration (0.0% vs 0.7%; P = .05), or embolization (0.0% vs 2.0%; P < .01) than Lotus. Valve areas remained significantly larger and the mean gradient was lower with CoreValve than Lotus (valve area, mean [SD]: Lotus, 1.53 [0.49] cm2 vs CoreValve, 1.76 [0.51] cm2; P < .01; valve gradient, mean [SD]: Lotus, 13.0 [6.7] mm Hg vs 8.1 [3.7] mm Hg; P < .01). Moderate or greater PVL was more frequent with CoreValve (0.3% Lotus vs 3.8% CoreValve; P < .01) at 2 years. Larger improvements in New York Heart Association (NYHA) functional class were observed with Lotus compared with CoreValve (improved by ≥1 NYHA class: Lotus, 338 of 402 [84.1%] vs CoreValve, 143 of 189 [75.7%]; P = .01; improved by ≥2 NYHA classes: 122 of 402 [37.3%] vs 65 of 305 [21.3%]).

Conclusions and Relevance

After 2 years, all-cause mortality rates, mortality or disabling stroke were similar between Lotus and CoreValve. Disabling stroke, functional class, valve migration, and PVL favored the Lotus arm whereas valve hemodynamics, thrombosis, and new pacemaker implantation favored the CoreValve arm.

Trial Registration

clinicaltrials.gov Identifier: NCT02202434.

Effect of Mechanically Expanded vs Self-Expanding Transcatheter Aortic Valve Replacement on Mortality and Major Adverse Clinical Events in High-Risk Patients With Aortic Stenosis: The REPRISE III Randomized Clinical Trial

IMPORTANCE

Transcatheter aortic valve replacement (TAVR) is established for selected patients with severe aortic stenosis. However, limitations such as suboptimal deployment, conduction disturbances, and paravalvular leak occur.

OBJECTIVE

To evaluate if a mechanically expanded valve (MEV) is noninferior to an approved self-expanding valve (SEV) in high-risk patients with aortic stenosis undergoing TAVR.

DESIGN, SETTING, AND PARTICIPANTS

The REPRISE III trial was conducted in 912 patients with high or extreme risk and severe, symptomatic aortic stenosis at 55 centers in North America, Europe, and Australia between September 22, 2014, and December 24, 2015, with final follow-up on March 8, 2017.

INTERVENTIONS

Participants were randomized in a 2:1 ratio to receive either an MEV (n = 607) or an SEV (n = 305).

MAIN OUTCOMES AND MEASURES

The primary safety end point was the 30-day composite of all-cause mortality, stroke, life-threatening or major bleeding, stage 2/3 acute kidney injury, and major vascular complications tested for noninferiority (margin, 10.5%). The primary effectiveness end point was the 1-year composite of all-cause mortality, disabling stroke, and moderate or greater paravalvular leak tested for noninferiority (margin, 9.5%). If noninferiority criteria were met, the secondary end point of 1-year moderate or greater paravalvular leak was tested for superiority in the full analysis data set.

RESULTS

Among 912 randomized patients (mean age, 82.8 [SD, 7.3] years; 463 [51%] women; predicted risk of mortality, 6.8%), 874 (96%) were evaluable at 1 year. The primary safety composite end point at 30 days occurred in 20.3% of MEV patients and 17.2% of SEV patients (difference, 3.1%; Farrington-Manning 97.5% CI, -∞ to 8.3%; P = .003 for noninferiority). At 1 year, the primary effectiveness composite end point occurred in 15.4% with the MEV and 25.5% with the SEV (difference, -10.1%; Farrington-Manning 97.5% CI, -∞ to -4.4%; P<.001 for noninferiority). The 1-year rates of moderate or severe paravalvular leak were 0.9% for the MEV and 6.8% for the SEV (difference, -6.1%; 95% CI, -9.6% to -2.6%; P < .001). The superiority analysis for primary effectiveness was statistically significant (difference, -10.2%; 95% CI, -16.3% to -4.0%; P < .001). The MEV had higher rates of new pacemaker implants (35.5% vs 19.6%; P < .001) and valve thrombosis (1.5% vs 0%) but lower rates of repeat procedures (0.2% vs 2.0%), valve-in-valve deployments (0% vs 3.7%), and valve malpositioning (0% vs 2.7%).

CONCLUSIONS AND RELEVANCE

Among high-risk patients with aortic stenosis, use of the MEV compared with the SEV did not result in inferior outcomes for the primary safety end point or the primary effectiveness end point. These findings suggest that the MEV may be a useful addition for TAVR in high-risk patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02202434.

Aortic Arch Morphology and Aortic Length in Patients with Dissection, Traumatic, and Aneurysmal Disease

OBJECTIVES

To assess aortic arch morphology and aortic length in patients with dissection, traumatic injury, and aneurysm undergoing TEVAR, and to identify characteristics specific to different pathologies.

METHOD

This was a retrospective analysis of the aortic arch morphology and aortic length of dissection, traumatic injury, and aneurysmal patients. Computed tomography imaging was evaluated of 210 patients (49 dissection, 99 traumatic injury, 62 aneurysm) enrolled in three trials that received the conformable GORE TAG thoracic endoprosthesis. The mean age of trauma patients was 43 ± 19.6 years, 57 ± 11.7 years for dissection and 72 ± 9.6 years for aneurysm patients. A standardized protocol was used to measure aortic arch diameter, length, and take-off angle and clockface orientation of branch vessels. Differences in arch anatomy and length were assessed using ANOVA and independent t tests.

RESULTS

Of the 210 arches evaluated, 22% had arch vessel common trunk configurations. The aortic diameter and the distance from the left main coronary (LMC) to the left common carotid (LCC) were greater in dissection patients than in trauma or aneurysm patients (p < .001). Aortic diameter in aneurysm patients was greater compared with trauma patients (p < .05). The distances from the branch vessels to the celiac artery (CA) were greater in dissection and aneurysm patients than in trauma patients (p < .001). The take-off angle of the innominate (I), LCCA, and left subclavian (LS) were greater, between 19% and 36%, in trauma patients than in dissection and aneurysm patients (p < .001). Clockface orientation of the arch vessels varies between pathologies.

CONCLUSIONS

Arch anatomy has significant morphologic differences when comparing aortic pathologies. Describing these differences in a large sample of patients is beneficial for device designs and patient selection.

Left Atrial Reduction Enhances Outcomes of Modified Maze Procedure for Permanent Atrial Fibrillation During Concomitant Mitral Surgery

BACKGROUND

Success of the maze procedure after mitral operations with large left atria and permanent atrial fibrillation remains suboptimal. Current technique variations tend to obscure the decision-making algorithm in these patients. A single energy-source approach for the surgical management of patients with large left atria and permanent atrial fibrillation is presented.

METHODS

From January 2003 to July 2005, 71 consecutive drug-resistant patients with permanent atrial fibrillation and left atrial enlargement who required mitral valve surgery underwent aggressive left atrial reduction combined with left-sided only irrigated radiofrequency unipolar maze. Left atrial dimensions were measured by transesophageal echo anterior-to-posterior leading edge-to-edge standardized protocol. There were 39 men (54.9%) and 32 women (45.1%), and their mean age was 71.9 +/- 9.5 years. Mean duration of atrial fibrillation was 49.3 +/- 58.0 months.

RESULTS

All patients underwent left atrial reduction with identical Cox-maze III pulmonary vein and appendage isolation including mitral annular connection, followed by appendage suture closure. Left atrial size was reduced from 6.7 +/- 1.2 cm to 4.3 +/- 0.6 cm (p = 0.001). Mitral valve repair was performed in 55 patients (76.1%) and replacement in 17 (23.9%). The 30-day mortality was 4.2% (3/71). Postoperative length of stay was 8.8 +/- 5.7 days, with 56 (82.4%) of 68 patients discharged in normal sinus rhythm. P-wave sinus rhythm was 93.8% between 7 and 12 months and 92.0% for patients with 1 year or more of follow-up.

CONCLUSIONS

Left atrial reduction combined with a left atrial only single energy-source radiofrequency maze procedure is an effective treatment for patients with permanent atrial fibrillation undergoing concomitant mitral operations.

Expression of focal adhesion kinase in normal and pathologic human prostate tissues

BACKGROUND

Focal adhesion kinase (FAK) regulates multiple cellular processes including growth, differentiation, adhesion, motility, and apoptosis. In tumor cells, including prostate adenocarcinoma, FAK overexpression has been linked to cancer progression.

METHODS

By using immunohistochemistry, FAK expression was investigated in human prostate specimens.

RESULTS

FAK was expressed predominantly in the basal layer of normal prostate epithelium but not in secretory epithelium. FAK was expressed at similar levels in all stages of prostate tumorigenesis, including preinvasive carcinoma and metastatic disease. Elevated FAK expression was observed at the earliest stages of transformation and expression continued during cancer progression.

CONCLUSION

Given the established role for FAK in the regulation of integrin signaling, we suggest that the sustained elevated levels of FAK expression during prostate tumor cell progression is consistent with a role for FAK in the development and maintenance of prostate carcinoma.

Alterations in the focal adhesion kinase/Src signal transduction pathway correlate with increased migratory capacity of prostate carcinoma cells

Focal adhesion kinase (FAK) has been implicated in the regulation of cell migration. In addition, FAK expression is increased in a number of highly metastatic tumor cell lines. Therefore, we investigated the role of FAK in regulating migration of prostate carcinoma cell lines with increasing metastatic potential. We show that highly tumorigenic PC3 and DU145 cells exhibit intrinsic migratory capacity, while poorly tumorigenic LNCaP cells require a stimulus to migrate. Increased metastatic potential of PC3 and DU145 cells correlates with increased FAK expression, overall tyrosine phosphorylation and activity, as measured by autophosphorylation of tyrosine 397. However, in PC3 and DU145 cells, FAK autophosphorylation is adhesion dependent whereas a second site of tyrosine phosphorylation, tyrosine 861, a Src specific site, is uncoupled from adhesion-dependent signaling events. Finally, inhibiting the FAK/Src signal transduction pathway by over expressing FRNK (Focal adhesion kinase-Related Non-Kinase), an inhibitor of FAK activation, or treatment with PP2, a Src family kinase inhibitor, significantly inhibited migration of prostate carcinoma cell lines, demonstrating that tumor cell migration continues to be dependent on signals emanating from this pathway.

Follow-Up Abdominal Computed Tomography after Splenic Trauma in Children May Not be Necessary

Nonoperative management of splenic injuries in children is well accepted. However, the need for follow-up abdominal CT to document splenic healing has not been well studied. We retrospectively reviewed initial and follow-up abdominal CT examinations of pediatric patients admitted to our institution with documented splenic trauma who were managed nonoperatively. Eighty-four patients were admitted to our pediatric surgical service with splenic injury documented by CT from 1994 through 1998. The standard approach for splenic injury was bedrest for 5 to 21 days and limited activity for up to 90 days at the discretion of the attending surgeon. Thirty-five of the 84 had follow-up CTs during outpatient follow-up to evaluate and document splenic healing by CT criteria. The initial and follow-up studies were randomized and read blindly by pediatric radiologists using a modified American Association for the Surgery of Trauma grading system (I–V). The age range of the patients was 6 months to 17 years (mean ± SE; 11 ± 1 years). Nineteen (54%) were male and 16 (46%) were female. Causes of splenic trauma included motor vehicle accident (22), fall (seven), assault (four), pedestrian versus vehicle (one), and sports injury (one). Eight children (23%) had grade II injuries, 14 (40%) had grade III injuries, and 13 children (37%) had grade IV injuries on initial CT scan. Seven (88%) of the grade II splenic injuries were healed by 64 ± 11 days. The remaining grade II injury had healed by 210 days. Thirteen (93%) of the grade III splenic injuries were healed by 76 ± 7 days. The remaining grade III injury was healed by 140 days. Spleens in 10 (77%) of the 13 patients with grade IV injuries were healed by 81 ± 8 days. Of the three remaining grade IV injuries two were healed by 173 ± 14 days. The remaining patient's spleen was radiologically considered to have a grade III defect 91 days from the time of injury, and no further CTs were obtained. Of the 34 patients who underwent follow-up CT imaging until splenic healing was demonstrated the mean time to complete healing was 87 ± 8 days postinjury (range 11–217 days). These data suggest that routine follow-up abdominal CTs may not be necessary to allow children to resume their normal activities after an appropriate time of restricted activity.

Follow-up abdominal computed tomography after splenic trauma in children may not be necessary

Nonoperative management of splenic injuries in children is well accepted. However, the need for follow-up abdominal CT to document splenic healing has not been well studied. We retrospectively reviewed initial and follow-up abdominal CT examinations of pediatric patients admitted to our institution with documented splenic trauma who were managed nonoperatively. Eighty-four patients were admitted to our pediatric surgical service with splenic injury documented by CT from 1994 through 1998. The standard approach for splenic injury was bedrest for 5 to 21 days and limited activity for up to 90 days at the discretion of the attending surgeon. Thirty-five of the 84 had follow-up CTs during outpatient follow-up to evaluate and document splenic healing by CT criteria. The initial and follow-up studies were randomized and read blindly by pediatric radiologists using a modified American Association for the Surgery of Trauma grading system (I-V). The age range of the patients was 6 months to 17 years (mean +/- SE; 11 +/- 1 years). Nineteen (54%) were male and 16 (46%) were female. Causes of splenic trauma included motor vehicle accident (22), fall (seven), assault (four), pedestrian versus vehicle (one), and sports injury (one). Eight children (23%) had grade II injuries, 14 (40%) had grade III injuries, and 13 children (37%) had grade IV injuries on initial CT scan. Seven (88%) of the grade II splenic injuries were healed by 64 +/- 11 days. The remaining grade II injury had healed by 210 days. Thirteen (93%) of the grade III splenic injuries were healed by 76 +/- 7 days. The remaining grade III injury was healed by 140 days. Spleens in 10 (77%) of the 13 patients with grade IV injuries were healed by 81 +/- 8 days. Of the three remaining grade IV injuries two were healed by 173 +/- 14 days. The remaining patient's spleen was radiologically considered to have a grade III defect 91 days from the time of injury, and no further CTs were obtained. Of the 34 patients who underwent follow-up CT imaging until splenic healing was demonstrated the mean time to complete healing was 87 +/- 8 days postinjury (range 11-217 days). These data suggest that routine follow-up abdominal CTs may not be necessary to allow children to resume their normal activities after an appropriate time of restricted activity.

A role for focal adhesion kinase in phenylephrine-induced hypertrophy of rat ventricular cardiomyocytes

A variety of agonists including phenylephrine (PE) induce hypertrophy in neonatal ventricular cardiomyocytes. Here we report that signals provided by extracellular matrix proteins (ECM) augment the PE-induced hypertrophic response of cardiomyocytes and provide evidence that ECM-dependent signaling is mediated in part by the protein tyrosine kinase, focal adhesion kinase (FAK). Addition of PE to cultured neonatal cardiomyocytes stimulated sarcomeric organization, increased cell size, and induced atrial natriuretic factor in cardiomyocytes plated on the ECM protein laminin or fibronectin. In contrast, cardiomyocytes plated on the non-adhesive substrate gelatin exhibited a reduced capacity to undergo these PE-stimulated hypertrophic changes. In cardiomyocytes cultured on ECM, PE stimulated a rapid increase in tyrosine phosphorylation of focal adhesion proteins including FAK, paxillin, and p130 Crk-associated substrate and subsequent formation of peripheral focal complexes. Inhibition of the PE-induced hypertrophic response by genistein and herbimycin-A indicated a requirement for protein tyrosine kinases in PE signaling. To determine whether activation of FAK is required for PE-induced hypertrophy, a dominant-interfering mutant form of FAK, termed FRNK (FAK-related non-kinase), was ectopically expressed in cardiomyocytes using a replication-defective adenovirus expression system. FRNK expression attenuated PE-stimulated hypertrophy as assessed by cell size, sarcomeric organization, and induction of atrial natriuretic factor. These data indicate that the signal transduction pathways leading to cardiomyocyte hypertrophy are strongly influenced by and/or dependent upon an integrin-mediated signaling process requiring FAK.

The role of peritoneal drainage for intestinal perforation in infants with and without necrotizing enterocolitis

BACKGROUND/PURPOSE

This report reviews our experience using peritoneal drainage (PD) as initial therapy for intestinal perforation in premature infants with and without necrotizing enterocolitis (NEC).

METHODS

A chart review was conducted of 18 consecutive premature infants who underwent PD for intestinal perforation from 1995 to 1998. Infants were divided into two groups. Group 1 consisted of eight infants who had intestinal perforation without evidence of NEC. Group 2 consisted of 10 infants who had perforation associated with evidence of NEC. A cohort of 10 infants with intestinal perforation treated with primary laparotomy between 1990 and 1995 was identified by chart review for historical control.

RESULTS

All infants improved immediately after PD. In group 1, all survived. Seven (88%) recovered systemically after PD. Of these, five (63%) never required laparotomy. Two (25%) required delayed laparotomy. One infant (12%) failed to continue to improve 48 hours after PD and underwent urgent laparotomy and recovered. In group 2, eight (80%) infants survived. Six (60%) recovered from NEC after PD, but five required delayed laparotomy for obstruction or persistent drainage. Four infants (40%) failed to progress from their initial improvement after PD. Three underwent laparotomy; two recovered and one had total intestinal necrosis and died. The fourth infant died without exploration and total intestinal necrosis was discovered during autopsy. Thus, seven of eight survivors (88%) in group 2 required laparotomy at some point in their course.

CONCLUSIONS

In premature infants with intestinal perforation, PD allows acute improvement and usually systemic recovery. In infants without evidence of NEC, PD may afford definitive treatment. In contrast, infants with evidence of NEC will likely require laparotomy, but initial PD may allow systemic stabilization and recovery of much of the involved intestine before laparotomy.

Sodium nitroprusside, an endothelium-derived relaxing factor congener, increases platelet cyclic GMP levels and inhibits epinephrine-exacerbated in vivo platelet thrombus formation in stenosed canine coronary arteries

Sodium nitroprusside (SNP), a nitrosovasodilator, increases platelet cyclic GMP levels and inhibits platelet activity in vitro. The antiplatelet properties of SNP are not well established in vivo, however, and consequently are not appreciated by clinicians. In our established model of mechanically stenosed canine coronary arteries (MSCA) with intimal damage, periodic acute platelet thrombus formation (APTF) occurs, followed by embolization distally, which then causes cyclic flow reductions (CFRs) in coronary blood flow. Aspirin (ASA) abolished platelet-mediated CFRs in our model, but they recur when epinephrine (EPI) is infused (0.2 microgram/kg/min). SNP was given continuously intravenously (i.v.) to 17 dogs with MSCA; CFRs were abolished in all dogs by SNP at 4.4 +/- 2.7 micrograms/kg/min (mean +/- SD). Mean arterial blood pressure (MAP) decreased by 19 +/- 9 mm Hg (p < 0.001) from control, while heart rate (HR) increased 35 +/- 20 beats/min (p < 0.001). Platelet cyclic GMP levels were 2.9 +/- 1.1 pmol/10(8) platelets before SNP infusion, and increased to 4.3 +/- 1.6 pmol/10(8) platelets (p < 0.05) when CFRs were abolished. CFRs were not renewed during the continued SNP infusion when EPI was infused at 0.2 microgram/kg/min for 20 min in 11 dogs, but CFRs returned within 5-25 min after the SNP infusion was terminated. The return of CFRs occurred together with a decrease in platelet cyclic GMP levels to 3.3 +/- 1.4 pmol/10(8) platelets.(ABSTRACT TRUNCATED AT 250 WORDS)