Simon C.Y. Chow

Hybrid Treatment for Ruptured Diverticulum of Kommerell: A Minimally Invasive Option

Although aberrant right subclavian artery is the commonest aortic arch anomaly, it is a rare entity in clinical practice. While mostly asymptomatic, the rupture of an aneurysm of an aberrant right subclavian artery or Kommerells diverticulum can be life threatening. A conventional open surgical approach involving sternotomy and resection of the abnormal vessels under circulatory support carries significant morbidity and mortality. We report a case of a ruptured diverticulum of Kommerell that was successfully treated with a hybrid debranching surgery, Amplatzer device embolization of the subclavian vessels, and thoracic aortic endovascular stenting.

Mediastinal follicular dendritic cell sarcoma with paraneoplastic pemphigus

Follicular dendritic cell sarcoma is a rare neoplasm of immune accessory cells. It occurs primarily in lymph nodes. Occurrences in the mediastinum are rarely reported. Diagnosis and management of follicular dendritic cell sarcoma remain unclear, and it is an under-recognized clinical entity. Only a few cases of paraneoplastic pemphigus as the first presentation of follicular dendritic cell sarcoma have been reported. We report an unusual case of follicular dendritic cell sarcoma of the anterior mediastinum, presenting as paraneoplastic pemphigus in a 62-year-old man. Typical histological features confirmed the diagnosis of follicular dendritic cell sarcoma, and surgical resection was successfully performed.

Endovascular Fenestration for Distal Aortic Sealing After Frozen Elephant Trunk With Thoraflex

We describe a case of total arch replacement with frozen elephant trunk for chronic type B aortic dissecting aneurysm, which resulted in inadvertent landing of the frozen elephant trunk into the false lumen. A radiofrequency puncture system-assisted controlled endovascular fenestration of the dissection flap was performed at the upper abdominal aorta and subsequent thoracic endovascular stenting, successfully redirecting the blood flow from the false to the true lumen. Our case illustrated a possible way to seal distal reentry in chronic type B aortic dissection.

Coil Embolization of Diverticulum of Kommerell: A Targeted Hybrid Endovascular Technique

A 57-year-old man was incidentally found to have a dissected diverticulum of Kommerell originating from aberrant origin of right subclavian artery during follow-up for treated colon cancer. A right carotid-axillary bypass was followed by embolization of aberrant artery and the diverticulum by deployment of multiple detachable coils using the Penumbra Ruby System (Penumbra, Alameda, CA). Angiography after embolization showed exclusion of flow to the aberrant artery and a patent right carotid-axillary bypass. The patient recovered uneventfully and remained well for 12 weeks after the operation, without any complications. We believe this targeted endovascular approach can avoid complications related to the coverage of thoracic aorta and reduce the risk of access vessel trauma.

Recent developments in video-assisted thoracoscopic surgery for pulmonary nodule management

In the modern era when screening and early surveillance of pulmonary nodules is increasing in importance, the management of the pulmonary nodule represents a different challenge to thoracic surgeons. The difficulty lies in the merging of sound surgical and oncological principles with more minimally invasive and appropriate lung sparing surgery. Furthermore, the intra-operative identification and surgical management of small and sometimes multi-focal pulmonary lesions remain challenging. There have been many developments and innovations in the field of video-assisted thoracoscopic surgery (VATS) to cater for the demands from increasing incidence of pulmonary nodules with associated paradigm shift in their surgical management. Recently, uniportal VATS and non-intubated VATS represent an even less invasive alternative to the conventional multiport VATS. The emergence of image guided VATS, hybrid operating theatre and fluorescence thoracoscopy have all contributed to improved precision of VATS lung resection, and are becoming important adjuncts to lung sparing surgery. In this chapter, some of these recent developments in VATS with emphasize on their importance in surgical management of the pulmonary nodule will be discussed.

Multi-dimensional printing in thoracic surgery: current and future applications

Three-dimensional (3D) printing has been gaining much attention in the medical field in recent years. At present, 3D printing most commonly contributes in pre-operative surgical planning of complicated surgery. It is also utilized for producing personalized prosthesis, well demonstrated by the customized rib cage, vertebral body models and customized airway splints. With on-going research and development, it will likely play an increasingly important role across the surgical fields. This article reviews current application of 3D printing in thoracic surgery and also provides a brief overview on the extended and updated use of 3D printing in bioprinting and 4D printing.

Transcatheter aortic valve implantation: the transaortic approach

Background Transcatheter aortic valve implantation has been established as a safe and effective treatment option for patients at high or prohibitive surgical risk. However, some patients may not be suitable for the transfemoral approach due to severe iliofemoral disease or aneurysmal disease of the thoracoabdominal aorta. The aim of this case series was to evaluate the feasibility and clinical outcomes of the transaortic approach. Methods From May 2015 to June 2016, 5 patients (mean age 78.4 ± 3.9 years) with severe symptomatic aortic stenosis underwent transaortic transcatheter aortic valve implantation after a heart team discussion. They were considered to be at high surgical risk and ineligible for the transfemoral approach due to iliofemoral or thoracoabdominal aortic disease. Results A CoreValve Evolut R was successfully deployed in all 5 patients. We performed 4 right mini-parasternal incisions and one J-incision partial sternotomy. None of the patients required permanent pacemaker implantation, one required reopening of the mini-parasternal incision for postoperative bleeding. Follow-up echocardiography one month after the procedure showed improvement in the mean aortic gradient (from 63.2 to 8.3 mm Hg) and aortic valve area (from 0.62 to 2.2 cm2). None of the patients had more than mild paravalvular leakage. There was no intraoperative or 30-day mortality. Conclusion Transaortic transcatheter aortic valve implantation is a safe and feasible option for patients with severe aortic stenosis who are considered unsuitable for transfemoral aortic valve implantation.

Alveolar rhabdomyosarcoma of the anterior mediastinum with vessel invasion in a 4-month-old boy: a case report

IntroductionAlveolar rhabdomyosarcomas of the mediastinum in children are rarely reported. Multimodality therapy including chemotherapy, surgery and radiotherapy make up the backbone of the treatment of childhood rhabdomyosarcomas. Complete resection whenever achievable is an important prognostic factor. However, complete resection of tumors in the mediastinum often poses a unique challenge to thoracic surgeons due to their close proximity to important neurovascular structures. Complete resection may not always be possible and judicious peri-operative planning and preparation are required to avoid creating unnecessary surgical morbidities resulting in delay of adjuvant therapy.Case presentationA 4-month-old Chinese baby boy was presented to our hospital with stridor, shortness of breath and episodes of cyanosis. Imaging studies found an anterior mediastinal mass compressing the trachea and other neurovascular structures and he was diagnosed to have alveolar rhabdomyosarcoma. Our patient received upfront chemotherapy and subsequently open resection of the mass was attempted via median sternotomy. Intraoperatively, the mass had invaded into the great vessels, precluding a complete resection. Debulking surgery was performed instead and our patient received timely postoperative chemoradiotherapy.ConclusionsWe report a rare case of childhood alveolar rhabdomyosarcoma of the mediastinum with vascular invasion treated with chemoradiotherapy and debulking surgery. Complete resection was not possible due to the close proximity to the great vessels. Different surgical approaches to the mediastinum have been reported in adults and children alike. Regardless of the surgical access, the treatment of childhood rhabdomyosarcomas should be individualized, with careful balance between surgical clearance and surgical morbidity.

Transcatheter aortic valve implantation: The evolving role of surgeons and challenges ahead

Transcatheter aortic valve implantation (TAVI) has revolutionized the management of aortic stenosis. Multiple seminal trials have firmly established TAVI as an effective and the preferred treatment in patients at high risk for surgical aortic valve replacement (SAVR). Following the success of the Placement of AoRTic TraNscathetER(PARTNER) 1 trial, TAVI was further proven to be a viable alternative to SAVR, with patients found to be at lower risk in the PARTNER 2 and Surgical or Transcatheter Aortic‐Valve Replacement (SURTAVI) trials. Contrary to the development of coronary intervention, surgeons from many parts of the world have adopted an active role in TAVI, rather than merely providing access. Moreover, as the use of TAVI has increased worldwide, and with developments in techniques and devices, experts are trying to expand the indications of TAVI to patients who are younger, fitter and at low risk for SAVR. Nonetheless, important questions concerning the risks and durability of TAVI remain unanswered. As the evolution of TAVI continues to gather pace, it is important for clinicians to critically evaluate the merits and shortcomings of TAVI to determine its suitability for low‐risk patients. The present review serves to highlight and discuss some of the challenges TAVI needs to overcome before its role in low risk patients can be established.

Updates on bronchoscopic management of airway disease: Bronchoscopic management of airway disease

Tracheobronchial surgery is one of the most challenging fields in thoracic surgery. Tremendous effort has been made to ensure that surgical resection and reconstruction of the tracheobronchial tree can be performed safely, and minimally‐invasive video assisted thoracoscopic surgery pioneers have recently pushed the limit for certain airway procedures. However, surgical resection of the diseased airway is often not feasible or contraindicated due to the nature of the disease or advanced malignancies. In the present, we focus on the endobronchial treatment of adult airway diseases and the latest updates.