Micky W.T. Kwok

Single-port sympathectomy for palmar hyperhidrosis with Vasoview Hemopro 2 endoscopic vein harvesting device.

Video-assisted thoracic surgery (VATS) sympathectomy is a well-accepted and definitive treatment for primary palmar hyperhidrosis, with a high success rate and low recurrence. The 3-port VATS approach typically uses 5to 10-mm instruments or needlescopic 3-mm instruments. The Vasoview Hemopro 2 (MAQUET Medical Systems, Wayne, NJ) endoscopic vein harvesting device has a 7-mm highdefinition thoracoscope, a parallel working channel for the Hemopro 2 dissector and automatic shut-off heat-sensing technology, a built-in CO2 gas insufflation channel, and a retractable lens-cleansing system all encompassed into one instrument, allowing simple single-port VATS procedures (Figure 1). The potential advantages are increased patient acceptance, minimal access trauma, reduced postoperative discomfort, and increased aesthetics. We present an innovative technique of VATS sympathectomy for palmar hyperhidrosis using the single-port Vasoview Hemopro 2 device.

Hybrid DynaCT Scan-Guided Localization Single-Port Lobectomy

Small pulmonary lesions can be difficult to locate intraoperatively. Preoperative CT scan-guided localization, for example with hookwire, is a popular method to help localize such lesions. However, the delay between CT scan localization with hookwire and surgery can lead to risks of pneumothorax and wire dislodgement. We describe a 56-year-old woman who underwent DynaCT-guided hookwire localization of a ground-glass opacity in the hybrid operating room followed immediately by single-port video-assisted thoracic surgery lobectomy. The advantages, disadvantages, and special considerations in adopting this approach are discussed.

Bone Morphogenic Protein-4 Contributes to Venous Endothelial Dysfunction in Patients With Diabetes Undergoing Coronary Revascularization

BACKGROUND Hyperglycemia-induced venous endothelial dysfunction accelerates the progression of vein graft failure in patients with diabetes undergoing surgical coronary revascularization. Recent studies suggest the importance of bone morphogenic protein-4 (BMP4)-induced arterial endothelial dysfunction in the development of hypertension and atherosclerosis. The present study investigated the potential role of BMP4 in the pathogenesis of venous endothelial dysfunction in the setting of diabetes. METHODS Segments of saphenous vein from pigs and from patients with diabetes or patients without diabetes, as well as human umbilical venous endothelial cells (HUVECs), were used. The changes of BMP4 expression in veins from patients and in HUVECs cultured under hyperglycemic conditions were evaluated by Western blot assay. The effects of BMP4 on the production of reactive oxygen species (ROS) and endothelium-dependent venous relaxation were assessed by using dihydroethidium fluorescence and isometric tension measurements, respectively. RESULTS The impaired venous endothelium-dependent relaxations (2.9%±4.8% versus control group 74.1%±10%; p<0.01) accompanied by markedly increased BMP4 expression were observed in the diabetic group. The level of BMP4 expression in HUVECs treated with high levels of glucose were elevated in a glucose concentration-dependent manner. Ex vivo treatment with the BMP4 antagonist noggin significantly improved endothelium-dependent relaxations and inhibited accumulation of ROS in saphenous veins from patients with diabetes. Noggin treatment had no effect on the venous endothelium-dependent relaxations in individuals without diabetes. Meanwhile, BMP4 inhibited acetylcholine-induced relaxation (control group, 90%±7.1% versus BMP4-treated group, 52%±12.6%; p<0.05) and enhanced ROS production in porcine saphenous veins. Such harmful effects were again reversed by noggin. CONCLUSIONS The increased BMP4 expression and related ROS overproduction may play an important role in the development of hyperglycemia-induced venous endothelial dysfunction.

Delayed fracture of MatrixRIB precontoured plate system

OBJECTIVES Use of titanium prostheses for reconstructing chest wall defects following major chest wall resections is rapidly increasing in popularity. Previously, complications including prosthesis fracture have been reported for the system secured to the rib ends using clips following chest wall reconstruction and pectus excavatum repair. By contrast, fracture failure in titanium systems fastening the plate to the rib with locking screws through predrilled holes has not been previously reported, possibly owing to differences in the design and material of the system. METHODS We report an index case of plate fracture in the latter design following rib reconstruction and discuss the pathophysiology and relative risks behind such fractures. RESULTS Fracture of titanium plate occurred after chest impact during sport at 25 months following initial plate implantation. Surgical excision was performed because of persistent pain and cough. CONCLUSIONS Fracture failure can occur in those systems fastening the plate to the rib with locking-screws, and patients, particularly those engaged in contact sports or occupations with chest impact risks, should be informed of this possibility during consent, as surgical removal is most likely required following implant fracture failur.

Mitral valve repair using a semirigid ring: patient selection and early outcomes

Background Commonly used complete mitral annuloplastic rings include saddle-shaped and semirigid rings, with no clear indication for either type. A semirigid ring may be preferred in patients whose native mitral saddle shape is well maintained. We present our experience of using semirigid rings for mitral valve repair. Methods We routinely measured the annular height-to-commissural width ratio by 3-dimensional transesophageal echocardiography prior to mitral repair. We generally chose a semirigid (Memo 3D) ring in patients whose annular height-to-commissural width ratio was normal (≥ 15%). The same semirigid ring with an additional chordal guiding system (Memo 3D ReChord) was selected for patients with anterior leaflet or bileaflet pathology. Over an 18-month period, 66 patients with severe degenerative (n = 60) or functional (n = 6) mitral regurgitation had Memo 3D (n = 32) or Memo 3D ReChord (n = 34) rings implanted. Results Postoperative 3-dimensional transesophageal echocardiography was completed in all patients (mean follow-up 7 ± 5 months). The majority of patients had no or mild residual mitral regurgitation; only two had moderate (2+) mitral regurgitation. There was no mortality at 30-days or on midterm follow-up. Conclusions Our series represents the first Asian clinical experience using the Memo 3D ReChord ring. Although the long-term durability of mitral repair with this type of semirigid annuloplastic ring warrants further validation, our current clinical data are encouraging.

Single-port video-assisted thoracoscopic lobectomy for early-stage nonsmall cell lung carcinoma

Single-port or uniport video-assisted thoracic surgery (VATS) has been gaining popularity in simple thoracic surgical procedures, such as sympathectomy, and pleural or lung biopsies. Recently, a Spanish group reported its successful attempt in performing singleport major lung resections, including lobectomy and pneumonectomy, in the literature. We describe our approach and surgical technique in single-port VATS right lower lobe lobectomy for early-stage nonsmall cell lung carcinoma.

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.

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.

Hybrid Rotational Angiography-Guided Localization Single-Port Lobectomy

Small pulmonary lesions can be difficult to locate intraoperatively. Preoperative CT scan-guided localization, for example with hookwire, is a popular method to help localize such lesions. However, the delay between CT scan localization with hookwire and surgery can lead to risks of pneumothorax and wire dislodgement. We describe a 56-year-old woman who underwent DynaCT-guided hookwire localization of a ground-glass opacity in the hybrid operating room followed immediately by single-port video-assisted thoracic surgery lobectomy. The advantages, disadvantages, and special considerations in adopting this approach are discussed.