CCAS Meeting Reviews
Morning Session III: Focus on a Lesion - Pulmonary Vein Stenosis
By Renee Olinda Gaver, MD
Vanderbilt University Medical Center
The last morning session, moderated by Nina Deutsch, MD (Children’s National Medical Center), focused on current catheter-based interventional management, surgical considerations and perioperative anesthetic considerations for the child with pulmonary vein stenosis (PVS).
Cardiac Interventional Management of PVS, presented by Ryan Callahan, MD from Boston Children’s Hospital, began with a review of the various etiologies of PVS, focusing on intraluminal proliferation and stenosis as a significant cause of disease in the CHD population.
Echocardiographic characteristics such as high right ventricular (RV) pressure, RV dysfunction, and turbulence in the pulmonary vein were illustrated. The utility of lung perfusion scans in providing diagnostic clarity was highlighted. Cardiac catheterization plays an important role in diagnosis and management by assessing hemodynamic status, delineating mechanism of obstruction and extent of PVS, and providing interventions to lower RV pressure by treating stenosis or restenosis.
Management of PVS is varied based on the presence of single vessel disease versus multi-vessel disease. While single vessel disease can be managed somewhat conservatively, the importance of aggressive management of multi-vessel disease with a multi-modal approach was emphasized. In addition to catheterization for diagnosis and initial treatment or palliation of PVS, a multi-modal approach includes possible surgery to relieve compression or anastomotic narrowing in order to promote laminar flow (theoretically minimizing the stimulus for restenosis) and initiation of a variety of available pharmacologic agents that prevent or mitigate intimal proliferation. Other aspects of management include evaluation for suitability for lung transplantation, frequent surveillance, nutritional management, pulmonology evaluation to optimize a patient’s respiratory status, and anti-coagulation management.
Dr. Callahan transitioned to a nice discussion and pictorial representation of various catheterization tools available to the interventionalist, including types of balloons (i.e. cutting vs. non-cutting), stents (drug-eluting, absorbable, etc.), with a discussion of the problem of in-stent stenosis. Re-canalization tools and an interesting example of the application of intravascular ultrasound were presented.
Complications related to catheter-based interventions were presented from a review of 915 procedures for PVS between 2005-2018. A 31% occurrence of ANY adverse event was seen with a 13% occurrence of severe adverse events, including one death, in this observational cohort. Serious adverse events included arrhythmia, vessel injury, respiratory complications including pulmonary hemorrhage, stroke, hemodynamic instability, and cardiac arrest.
PVS continues as a disease that is associated with poor long-term prognosis. Predictors of survivability include age at presentation, number of veins affected, presence of distal disease, pulmonary artery pressure and degree of RV dysfunction.
Christopher Caldarone, MD from Texas Children’s Hospital, spoke on the Surgical Management of the child with PVS. Recognizing the dismal prognosis of PVS, Dr. Caldarone elucidated the problem of finding solutions to a disease that is infrequently studied and rare, therefore resulting in limited individual experience with no central registry or guidelines. The result of which is divided efforts by clinicians. He described the exhaustive efforts by Dr. Rachel Vanderlaan at Sick Kids and her work creating a dedicated PVS Team comprised of a Clinical PVS team, a dedicated lab, clinical trials, and a PVS network. The PVS team concentrates on management with links to transplant teams, palliative care teams, surgeons, cardiologists, interventionalists, radiologists, and echocardiography. The focus is on frequent surveillance and intervention utilizing ECHO, CT/MRI, diagnostic catheterization and intervention with patients receiving follow-up at one, six, and 12 months following an intervention. If there is recurrence or progression of the PVS, the patient proceeds either to surgery or catheter-based intervention and may be started on pharmacologic therapy such as Losartan. Once the patient has been declared a “fast progressor”, they enter a pro-active management cycle with monthly assessment and consideration for transplantation or palliative care.
Next, Dr. Caldarone discussed surgical management of the disease utilizing “suture-less” repairs, which result in lower restenosis rates. He described combined surgical and catheter-based interventions with stent placement. He also commented on the high in-stent stenosis rates associated with such procedures. Losartan has shown promise in decreasing the occurrence of intraluminal endothelial stenosis.
Lung transplantation was discussed as a surgical option for some patients. ECMO requirement post-transplant is the main predictor of 1-year mortality. Several novel options were discussed as beneficial in bridging patients to transplant including RA-LA pumps, PA-LA pumps and the PLAD (para-corporeal lung assist device). To give us all hope, he showed a great picture of a teenage girl surfing after bridging to transplant with a PLAD and having a successful outcome.
He concluded by mentioning the following new initiatives to treat PVS: Suture-less repairs, Pro-active aggressive management cycle, Bio-absorbable stents, Drug eluting stents, Losartan, Gleevec/Avastin, Transplant, Mechanical Pulmonary support, PVS team, and PVS Network.
The last presentation of Session III was given by Morgan L. Brown, MD, PhD, from Boston Children’s Hospital, discussing Perioperative Management of the pediatric patient with PVS.
Preoperative assessment initially relies on ECHO data to give information on pulmonary vein gradients, RV function, RV systolic pressure, presence of tricuspid regurgitation, septal positioning, presence of concomitant LV dysfunction, and presence of intracardiac shunts (atrial, ventricular). Medical therapy may include diuretics (which may be reflected in acid-base abnormalities and have significance with regard to ventilation strategies), oxygen, chemotherapeutic agents (Gleevec, Avastin), pulmonary hypertension (PHTN) therapies and anticoagulation medications (aspirin, Lovenox). Many patients with PVS may have gastrostomy tubes or G-J tubes for nutritional supplementation and are at increased risk for hypoglycemia with prolonged fasting prior to procedures.
Basic principles of anesthetic management of PVS were reviewed. Supporting the RV and avoiding hypotension is paramount. To that end, starting a procedure with an inotropic agent pre-induction or immediately available was recommended. Avoidance of fluid boluses and administration of diuretics at the conclusion of the case were suggested. The decision to extubate the child is predicated on the occurrence or significance of any pulmonary hemorrhage, hemodynamic instability, need for post-procedure sedation and the risk with a native airway of hypoventilation and subsequent RV decompensation. Extubation should be weighed against the alternative of leaving the child intubated and transferring care to the Pediatric Cardiac Intensive Care Unit.
Significant adverse events that may occur following catheter-based interventions include pulmonary hemorrhage and stroke. Pulmonary hemorrhage can usually be managed with rapid suctioning of the endotracheal tube followed by 15 of PEEP for 15 minutes before breaking the circuit to reevaluate. If the pulmonary hemorrhage resolves, extubation can still be considered. If it persists, the patient should remain intubated and be transferred to the ICU for further management. Stroke is a major adverse event and a neurologic exam should seek the presence or absence of new neurologic deficits as quickly as feasible. If a child is to remain intubated, it was suggested that the depth of sedation should be lifted to ascertain neurologic status. Patients undergoing operative procedures are at risk of increased pulmonary vein compression from the placement of a TEE probe. Problems associated with surgical repair of PVS are those typical to children undergoing CPB such as bleeding, RV dysfunction and ventilation issues (especially in the presence of pulmonary hemorrhage).
Risk factors for heightened perioperative concerns for the child with PVS presenting for procedures: <6mos of age, Multivessel disease, Single ventricle physiology, RV dysfunction, Difficult airway, Known PHTN, Long procedure, and Pulmonary hemorrhage.
Session III was very well received by the audience and concluded with a brief audience Q/A session.
