Discussion:
Pulmonary embolism is a major cause of cardiovascular mortality.3 Most clinical guidelines only recommend surgical embolectomy for massive PE and only when thrombolysis has failed, is contraindicated, or for patients presenting in extremis with cardiopulmonary collapse.1,4 Emerging data from our institution and others support the extended utility of surgical embolectomy for treatment of massive PE. As we previously wrote, recent reports highlighting improved surgical techniques have shown that surgical pulmonary embolectomy yields similar 30-day and 5-year mortality rates compared to thrombolytic therapy. 5,6However, compared to thrombolysis, surgical pulmonary embolectomy was associated with lower rates of bleeding complications, stroke, and requirement for re-intervention within 30 days.6
Our introduction of the MIPE via a left mini thoracotomy highlights an advancement in surgical embolectomy in that it avoids sternotomy and related complications allowing for enhanced recovery. With continued experience with the MIPE we offer the following as important lessons learned after our initial description1.
  1. Location of the anterior thoracotomy should be based on pre-operative axial and sagittal imaging rather than adhering to a standardized third interspace. In the case presented the 3rdintercostal space was too inferior and created difficulty with exposure and visualization of the PA. The subsequent MIPE procedures done at our institution have been performed via the 2nd intercostal space with improved exposure and ease of surgery.
  2. Appropriate venous drainage of the heart is important to successfully complete the operation. In the case presented, the single venous drainage catheter placed from the femoral vein going up into the right atrium may have slipped back into the IVC during surgery, or was not capable of sufficient drainage in the large patient, or combination of both factors, thus causing the right ventricle to not adequately decompress and forced us to rely on robust suctioning within the pulmonary arteriotomy to successfully complete the case. We now employ dual venous drainage (placed via the common femoral vein into the RA and the internal jugular vein into the SVC-RA junction) to ensure proper venous drainage which allowed for improved visualization and clot extraction.
  3. Closure of the pulmonary arteriotomy can be much more easily facilitated by placement of a purse-string suture about the planned arteriotomy prior to incision. We intend to employ this technique, here forward, for PA closure.
  4. Early utilization of Aerosolized Epoprostenol is an important adjunct to aid the recovering right ventricle.
  5. Care of patients with massive pulmonary embolism requires a team based, multi-disciplinary approach. The care of this patient involved consulting services including vascular surgery, hematology, nephrology, physical therapy and social work services.
  6. While we have demonstrated a low rate of complications, and zero mortality from this procedure in our previous report1, the case presented highlights that while we were able to perform the MIPE, complications did still occur (prolonged ventilatory and inotropic support to aid the recovering right heart, AKI, HIT) and are to be expected with any patient who requires surgery for pulmonary embolus due to the inherent risk of cardiopulmonary bypass. Even so, we believe that recovery from the small mini anterior thoracotomy as described compared to a standard sternotomy may be easier and simpler for patients.
In summary, we have detailed several augmentations to our original description of the MIPE.1 We believe the operation and results are reproducible and can be a valuable tool in the armamentarium of the cardiothoracic surgeon.
References:
1. Fallon J, Luvika G, Zapata D, Lattouf O. Initial Experience with Non-Sternotomy Minimally Invasive Pulmonary Embolectomy with Thoracoscopic Assistance. Innovations 2020, Vol. 15(2) 180–184
2. Fallon J. Minimally Invasive Pulmonary Embolectomy With Thoracoscopic Assistance. doi:10.25373/CTSNET.11964948
3. Bĕlohlávek J, Dytrych V, Linhart A. Pulmonary embolism, part I: Epidemiology, risk factors and risk stratification, pathophysiology, clinical presentation, diagnosis and nonthrombotic pulmonary embolism.Exp Clin Cardiol . 2013;18(2):129-138. http://www.ncbi.nlm.nih.gov/pubmed/23940438. Accessed March 8, 2020.
4. Konstantinides S V., Torbicki A, Agnelli G, et al. 2014 ESC Guidelines on the diagnosis and management of acute pulmonary embolism.Eur Heart J . 2014;35(43):3033-3080. doi:10.1093/eurheartj/ehu283
5. Aymard T, Kadner A, Widmer A, et al. Massive pulmonary embolism: surgical embolectomy versus thrombolytic therapy–should surgical indications be revisited? Eur J Cardiothorac Surg . 2013;43(1):90-94; discussion 94. doi:10.1093/ejcts/ezs123
6. Lee T, Itagaki S, Chiang YP, Egorova NN, Adams DH, Chikwe J. Survival and recurrence after acute pulmonary embolism treated with pulmonary embolectomy or thrombolysis in New York State, 1999 to 2013. J Thorac Cardiovasc Surg . 2018;155(3):1084-1090.e12. doi:10.1016/j.jtcvs.2017.07.074
Image 1: Computed tomography showing: (A) saddle pulmonary embolus (B) right ventricle strain with right ventricular size larger than left ventricle in diastolic phase.