Catheterization and Cardiovascular Interventions 85:428–429 (2015)
Editorial Comment Covered Stents—We Need Them, But It Would Be Better If We Didn’t Larry A. Latson,* MD, FSCAI, FACC Joe DiMaggio Childrens Hospital/Memorial Healthcare System, Hollywood, FL
Key Points
Right ventricular outflow tract conduit disruption occurs in about 6% of transcatheter pulmonary valve placement procedures, with highest risk in patients with larger gradients The Covered Cheatham-Platinum Stent is an effective treatment for acute events, but longer-term follow-up data is still lacking Pre-placement of a covered stent in high risk patients should be further evaluated
In this issue of Catheterization and Cardiovascular Interventions, Bishnoi et al. reviewed the results of the NuMED Covered Cheatham-Platinum Stents (CCPS) used in procedures to treat or prevent right ventricular outflow tract (RVOT) conduit disruptions in patients undergoing transcatheter pulmonary valve replacement [1]. Data for the study came from procedures performed in the United States between 2009 and 2012 in which a CCPS was implanted under the Emergency or Compassionate Use guidelines of the FDA. Although the CCPS has been widely available in many countries for over 10 years, it is still an investigational device in the US. In the current report, at least one CCPS was implanted in 50 patients—43 with demonstrated disruption of the RVOT (9 pre-existing, 34 developing during the procedure), and 7 in whom the CCPS was placed prophylactically at the discretion of the operator. The data confirm that the CCPS can be implanted with a high success rate, even under urgent circumstances. Disruptions were successfully treated in all patients except one, who apparently stabilized, but still had to go to surgery three days later. There was no indication that valve function was impaired when a transcatheter pulmonary valve was placed inside of a CCPS. The C 2015 Wiley Periodicals, Inc. V
authors rightly pointed out that there are some concerns about the long-term structural integrity of the CCPS. Although no stent fractures were identified in the specified 6-month follow-up of the study, the authors were aware of one patient with stent fracture requiring additional treatment three years after CCPS placement. Confirmation that placement of a CCPS has a high likelihood of salvaging a patient with a RVOT conduit disruption is certainly welcome. However, our goal should be to prevent, rather than urgently treat, these potentially life-threatening events that are seen in about 6% of cases using current selection criteria and techniques. A closer look at the data from this article shows that, in the really emergent, uncontained disruptions, the CCPS was successful in preventing surgical intervention in three out of four procedures. However, half required chest tube placement, and that is a lot more “drama” than we want to see in our catheterizations labs. We need to better understand which patients have a significant risk for developing a disruption. Homografts are often viewed as a significant risk for disruption, and in this study, all of the “uncontained” disruptions occurred in homografts. However, 14% of the CCPSs were placed in patients with a bioprosthetic valve or conduit, and 4% were placed in a native right ventricular outflow tract. It is not clear which of these non-homograft placements were for a disruption versus prophylactic placement at the discretion of the operator. Statistical analysis indicated that a higher initial systolic gradient was associated with increased risk, but did not identify a specific value for the gradient that would reliably predict disruption. The study was not designed to test whether gradual serial dilations may protect against disruption. None of the seven patients in the present study who had a CCPS placed prophylactically had a complication or evidence of disruption. It is attractive to hope that a Conflict of interest: Nothing to report. *Correspondence to: Larry Latson, Joe DiMaggio Children’s Hospital, Pediatric Cardiology, 1150 N 35th Ave Suite 575, Hollywood, Florida 33021. E-mail: [email protected] Key Points Received 19 December 2014; Revision accepted 21 December 2014 DOI: 10.1002/ccd.25804 Published online 9 February 2015 in Wiley Online Library (wileyonlinelibrary.com)
Covered Stents
strategy of prophylactic covered stent placement in all patients would prevent all right ventricular outflow tract conduit disruptions. However this strategy needs more evaluation. In the current study, a number of patients required multiple covered stents. Some patients required a CCPS after placement of the Melody valve—itself a covered stent. So disruptions can occur at, or extend beyond, expected locations. The initial cost and time required for placement of a large covered pre-stent in every patient would need to be evaluated. Finally, the long-term issue of stent fracture, and even late embolization of stent fragments, in patients who may not have needed a covered stent needs to be considered. I believe that the data supports the perceived need for availability of the CCPS in any labs performing transcatheter pulmonary valve replacement procedures with current devices and techniques. These covered stents clearly can be life saving in an emergency. Availability of covered stents, however, will not solve all the concerns about transcatheter pulmonary valve replacements. We need more information to risk stratify
429
sub-sets of patients before a procedure is even considered. We need to continue development of techniques to perform transcatheter pulmonary valve replacement procedures with less risk. We need to better understand the longer-term outcomes of implanted CCPSs to assess whether steps to strengthen them are needed. We need continued evaluations of data from multiple sources, including large national and international registries, to eventually enable us to discern reliably when current techniques for transcatheter pulmonary valve replacement are high risk, when prophylactic placement of some type of covered stent is most reasonable, and when it may really be best to send the patient for surgical pulmonary valve replacement. REFERENCE 1. Bishnoe RN, Jones TK, Kreutzer J, Ringel RE. NuMED covered cheatham-platinum stent for treatment of right ventriculary outflow tract conduit disruption during transcatheter pulmonary valve replacement. Catheter Cardiovasc Interv 2014;85:421–427.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
Editorial Comment Covered Stents—We Need Them, But It Would Be Better If We Didn’t Larry A. Latson,* MD, FSCAI, FACC Joe DiMaggio Childrens Hospital/Memorial Healthcare System, Hollywood, FL
Key Points
Right ventricular outflow tract conduit disruption occurs in about 6% of transcatheter pulmonary valve placement procedures, with highest risk in patients with larger gradients The Covered Cheatham-Platinum Stent is an effective treatment for acute events, but longer-term follow-up data is still lacking Pre-placement of a covered stent in high risk patients should be further evaluated
In this issue of Catheterization and Cardiovascular Interventions, Bishnoi et al. reviewed the results of the NuMED Covered Cheatham-Platinum Stents (CCPS) used in procedures to treat or prevent right ventricular outflow tract (RVOT) conduit disruptions in patients undergoing transcatheter pulmonary valve replacement [1]. Data for the study came from procedures performed in the United States between 2009 and 2012 in which a CCPS was implanted under the Emergency or Compassionate Use guidelines of the FDA. Although the CCPS has been widely available in many countries for over 10 years, it is still an investigational device in the US. In the current report, at least one CCPS was implanted in 50 patients—43 with demonstrated disruption of the RVOT (9 pre-existing, 34 developing during the procedure), and 7 in whom the CCPS was placed prophylactically at the discretion of the operator. The data confirm that the CCPS can be implanted with a high success rate, even under urgent circumstances. Disruptions were successfully treated in all patients except one, who apparently stabilized, but still had to go to surgery three days later. There was no indication that valve function was impaired when a transcatheter pulmonary valve was placed inside of a CCPS. The C 2015 Wiley Periodicals, Inc. V
authors rightly pointed out that there are some concerns about the long-term structural integrity of the CCPS. Although no stent fractures were identified in the specified 6-month follow-up of the study, the authors were aware of one patient with stent fracture requiring additional treatment three years after CCPS placement. Confirmation that placement of a CCPS has a high likelihood of salvaging a patient with a RVOT conduit disruption is certainly welcome. However, our goal should be to prevent, rather than urgently treat, these potentially life-threatening events that are seen in about 6% of cases using current selection criteria and techniques. A closer look at the data from this article shows that, in the really emergent, uncontained disruptions, the CCPS was successful in preventing surgical intervention in three out of four procedures. However, half required chest tube placement, and that is a lot more “drama” than we want to see in our catheterizations labs. We need to better understand which patients have a significant risk for developing a disruption. Homografts are often viewed as a significant risk for disruption, and in this study, all of the “uncontained” disruptions occurred in homografts. However, 14% of the CCPSs were placed in patients with a bioprosthetic valve or conduit, and 4% were placed in a native right ventricular outflow tract. It is not clear which of these non-homograft placements were for a disruption versus prophylactic placement at the discretion of the operator. Statistical analysis indicated that a higher initial systolic gradient was associated with increased risk, but did not identify a specific value for the gradient that would reliably predict disruption. The study was not designed to test whether gradual serial dilations may protect against disruption. None of the seven patients in the present study who had a CCPS placed prophylactically had a complication or evidence of disruption. It is attractive to hope that a Conflict of interest: Nothing to report. *Correspondence to: Larry Latson, Joe DiMaggio Children’s Hospital, Pediatric Cardiology, 1150 N 35th Ave Suite 575, Hollywood, Florida 33021. E-mail: [email protected] Key Points Received 19 December 2014; Revision accepted 21 December 2014 DOI: 10.1002/ccd.25804 Published online 9 February 2015 in Wiley Online Library (wileyonlinelibrary.com)
Covered Stents
strategy of prophylactic covered stent placement in all patients would prevent all right ventricular outflow tract conduit disruptions. However this strategy needs more evaluation. In the current study, a number of patients required multiple covered stents. Some patients required a CCPS after placement of the Melody valve—itself a covered stent. So disruptions can occur at, or extend beyond, expected locations. The initial cost and time required for placement of a large covered pre-stent in every patient would need to be evaluated. Finally, the long-term issue of stent fracture, and even late embolization of stent fragments, in patients who may not have needed a covered stent needs to be considered. I believe that the data supports the perceived need for availability of the CCPS in any labs performing transcatheter pulmonary valve replacement procedures with current devices and techniques. These covered stents clearly can be life saving in an emergency. Availability of covered stents, however, will not solve all the concerns about transcatheter pulmonary valve replacements. We need more information to risk stratify
429
sub-sets of patients before a procedure is even considered. We need to continue development of techniques to perform transcatheter pulmonary valve replacement procedures with less risk. We need to better understand the longer-term outcomes of implanted CCPSs to assess whether steps to strengthen them are needed. We need continued evaluations of data from multiple sources, including large national and international registries, to eventually enable us to discern reliably when current techniques for transcatheter pulmonary valve replacement are high risk, when prophylactic placement of some type of covered stent is most reasonable, and when it may really be best to send the patient for surgical pulmonary valve replacement. REFERENCE 1. Bishnoe RN, Jones TK, Kreutzer J, Ringel RE. NuMED covered cheatham-platinum stent for treatment of right ventriculary outflow tract conduit disruption during transcatheter pulmonary valve replacement. Catheter Cardiovasc Interv 2014;85:421–427.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
