Clinical Focus


  • Cardiothoracic Surgery

Academic Appointments


Professional Education


  • Fellowship: UCSF Dept of General Surgery (2011) CA
  • Board Certification: Japan Surgical Society, General Surgery (2004)
  • Board Certification: Japanese Board of Cardiovascular Surgery, Cardiothoracic Surgery (2009)
  • Fellowship: Emory University School of Medicine (2012) GA
  • Fellowship: Tokyo Women's Medical School (2009)
  • Fellowship: Gifu Prefectural General Medical Center (2008) Japan
  • Residency: Tokyo Women's Medical School (2005)
  • Internship: Gifu University Medical School (2000) Japan
  • Medical Education: Gifu University Medical School (1999) Japan

All Publications


  • Complete repair for Scimitar syndrome with transitional atrioventricular canal ASIAN CARDIOVASCULAR & THORACIC ANNALS Watanabe, N., Manohar, N., Hapak, A., Nasirov, T. 2022: 2184923221080154

    Abstract

    We describe an extremely rare case of a 15-year-old female, who underwent a complete repair for transitional atrioventricular canal with Scimitar syndrome by a two-patch technique including translocation of the Scimitar vein. This surgical technique offered superior patch shapes in order to better repair both anomalies.

    View details for DOI 10.1177/02184923221080154

    View details for Web of Science ID 000772392700001

    View details for PubMedID 35285283

  • Neonatal right mini thoracotomy for repair of critical pulmonary stenosis. Asian cardiovascular & thoracic annals Watanabe, N., Kovalenko, O., Hapak, A., Nasirov, T. 2021: 2184923211029391

    Abstract

    Over the last few decades, due to evolving surgical techniques and medical management, there has been a significant decrease in the rate of mortality and complications for neonates born with critical pulmonary valve stenosis. Median sternotomy is the standard approach; however, this longitudinal midline incision is invasive and leaves a significant scar. A right mini thoracotomy approach to this surgical repair decreases recovery time and the chance of possible future psychological distress from a visible median sternotomy scar. This is the first article to describe a right mini thoracotomy approach for critical pulmonary stenosis during the neonatal period.

    View details for DOI 10.1177/02184923211029391

    View details for PubMedID 34225461

  • Biatrial connection of partial anomalous pulmonary venous return. Asian cardiovascular & thoracic annals Watanabe, N., Fallah, H., Pugh, C., Nasirov, T. 2017: 218492317704526-?

    Abstract

    We describe an extremely rare case of partial anomalous pulmonary venous return in a 3-year-old boy with an abnormal connection between the right upper pulmonary vein and the right middle pulmonary vein, which created biatrial communication hemodynamically. Patch closure on the orifice of the right upper pulmonary vein was performed to avoid distortion or kinking of the right pulmonary veins and the connection.

    View details for DOI 10.1177/0218492317704526

    View details for PubMedID 28361581

  • An Analysis of Left Ventricular Retraining in Patients With Dextro- and Levo-Transposition of the Great Arteries. The Annals of thoracic surgery Mainwaring, R. D., Patrick, W. L., Ibrahimiye, A. N., Watanabe, N. n., Lui, G. K., Hanley, F. L. 2017

    Abstract

    Patients with dextro (D)-transposition of the great arteries (TGA) who have undergone a previous atrial switch and for some patients with levo (L)-TGA (ie, no ventricular septal defect or outflow tract obstruction), the left ventricle (LV) may require retraining before late arterial switch. The purpose of this study was to analyze the results of LV retraining for these two entities.This was a retrospective review of 51 patients enrolled in an LV retraining program. There were 25 patients with D-TGA and 26 with L-TGA. The median age of the D-TGA patients was 15 years, and 22 of 25 were in New York Heart Association class III or IV. The median age of the L-TGA patients was 12 months, and 3 of 26 patients were in New York Heart Association class III or IV.LV retraining was successful in 13 of the 25 patients (52%) with D-TGA, and 10 these 13 patients (77%) underwent successful late arterial switch. Of the 26 patients with L-TGA, LV retraining was successful in 24 (92%), and a double-switch operation was successful in 19 of 19 (100%) who subsequently underwent that procedure. A mathematical formula based on the incremental gain in left-to-right ventricular pressure ratio correctly predicted the success or failure in 94% of the patients.The data demonstrate differences in the success of LV retraining and late arterial switch for D-TGA and L-TGA. We would propose that the LV retraining ratio may be useful in objectively selecting patients eligible for late arterial switch.

    View details for PubMedID 29274314

  • Left Ventricular Retraining and Late Arterial Switch for D-Transposition of the Great Arteries. Annals of thoracic surgery Watanabe, N., Mainwaring, R. D., Carrillo, S. A., Lui, G. K., Reddy, V. M., Hanley, F. L. 2015; 99 (5): 1655-1661

    Abstract

    For many decades, patients with d-transposition of the great arteries underwent an atrial switch procedure. Although many of these patients have continued to do well, a subset experience profound right ventricular failure. Some may be candidates for left ventricular (LV) retraining and late arterial switch. The purpose of this study was to review our experience with LV retraining and late arterial switch.This was a retrospective review of 32 patients with d-transposition. Thirty patients underwent a previous atrial switch and subsequently experienced right ventricular failure, whereas 2 presented late (8 months and 6 years) without previous intervention. The median age at the time of enrollment in this program was 15 years. Seven patients proceeded directly to late arterial switch owing to systemic LV pressures. The remaining 25 underwent a pulmonary artery band for LV retraining.Twenty of the 32 (63%) patients enrolled in this program were able to undergo a late arterial switch. There were 2 operative mortalities (10%). Two additional patients survived surgery but died in the early outpatient time period. There has been no late mortality after the arterial switch with a median follow-up of 5 years. Twelve patients underwent one or more pulmonary artery band procedures without evidence of effective LV retraining. There have been 2 early and 3 late (42%) deaths in this subgroup.The outcomes after arterial switch are encouraging and suggest that LV retraining and late arterial switch provide a viable option for this complex group of patients.

    View details for DOI 10.1016/j.athoracsur.2014.12.084

    View details for PubMedID 25817887

  • Left Ventricular Retraining and Late Arterial Switch for D-Transposition of the Great Arteries ANNALS OF THORACIC SURGERY Watanabe, N., Mainwaring, R. D., Carrillo, S. A., Lui, G. K., Reddy, V. M., Hanley, F. L. 2015; 99 (5): 1655-1663

    Abstract

    For many decades, patients with d-transposition of the great arteries underwent an atrial switch procedure. Although many of these patients have continued to do well, a subset experience profound right ventricular failure. Some may be candidates for left ventricular (LV) retraining and late arterial switch. The purpose of this study was to review our experience with LV retraining and late arterial switch.This was a retrospective review of 32 patients with d-transposition. Thirty patients underwent a previous atrial switch and subsequently experienced right ventricular failure, whereas 2 presented late (8 months and 6 years) without previous intervention. The median age at the time of enrollment in this program was 15 years. Seven patients proceeded directly to late arterial switch owing to systemic LV pressures. The remaining 25 underwent a pulmonary artery band for LV retraining.Twenty of the 32 (63%) patients enrolled in this program were able to undergo a late arterial switch. There were 2 operative mortalities (10%). Two additional patients survived surgery but died in the early outpatient time period. There has been no late mortality after the arterial switch with a median follow-up of 5 years. Twelve patients underwent one or more pulmonary artery band procedures without evidence of effective LV retraining. There have been 2 early and 3 late (42%) deaths in this subgroup.The outcomes after arterial switch are encouraging and suggest that LV retraining and late arterial switch provide a viable option for this complex group of patients.

    View details for DOI 10.1016/j.athoracsur.2014.12.084

    View details for Web of Science ID 000353877900040

    View details for PubMedID 25817887

  • Early complete repair of pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals. Annals of thoracic surgery Watanabe, N., Mainwaring, R. D., Reddy, V. M., Palmon, M., Hanley, F. L. 2014; 97 (3): 909-915

    Abstract

    Pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals (PA/VSD/MAPCAs) is a complex and diverse form of congenital heart defect. Although most patients with PA/VSD/MAPCAs can wait until they are 3 to 6 months of age to undergo surgical reconstruction, there are three specific criteria that merit an earlier repair. These 3 criteria are (1) unremitting heart failure; (2) a ductus to one lung and MAPCAs to the other; and (3) hemitruncus to one lung and MAPCAs to the other. The purpose of this study was to evaluate our surgical experience with early complete repair of PA/VSD/MAPCAs.This was a retrospective review of patients undergoing complete repair of PA/VSD/MAPCAs within the first 60 days of life. Twenty-seven patients were identified in our database (2002 to 2013) who met these criteria. Fifteen had congestive heart failure, 9 had a ductus plus MAPCAs, and 3 had hemitruncus plus MAPCAs. The median age at surgery was 5 weeks.There was no operative mortality in this cohort of 27 patients. Hemodynamics at the conclusion of the complete repair demonstrated an average right ventricular peak systolic pressure of 32 ± 5 mm Hg and an average right ventricle to aortic pressure ratio of 0.36 ± 0.06. The median length of hospital stay was 26 days. There have been 2 subsequent mortalities (7%), with a median follow-up duration of 4 years. Eight of the 27 patients have subsequently undergone conduit replacements at our institution. The hemodynamics at the conclusion of the conduit change were statistically unchanged compared with the hemodynamics after complete repair.The data demonstrate that early complete repair of PA/VSD/MAPCAs can be accomplished with low mortality and excellent postoperative hemodynamics. These early hemodynamic results are maintained at medium-term follow-up. We conclude that early complete repair is an appropriate choice for this highly select subgroup of patients.

    View details for DOI 10.1016/j.athoracsur.2013.10.115

    View details for PubMedID 24480261