Minimally invasive perventricular device closure of ventricular septal defect: a comparative study in 80 patients.

OBJECTIVE: To evaluate the efficacy of minimally invasive perventricular device closure of ventricular septal defect (VSD). METHODS: Between September 2011 and February 2013, we collected 40 patients who underwent perventricular closure via a small lower sternal incision (minimally invasive group), aged 15.5±3.5 years (12 months to 32 years) with a body weight of 24.2±7.5 kg (10.8-58.0 kg). The mean size of VSD was 5.6±0.5 mm (2-14 mm). Another 40 patients were included as the surgical group, receiving the conventional surgical repair of VSD. The device of the minimally invasive group was released under the guidance of transesophageal echocardiography. Success rate, cardiac indicators, and clinical outcomes of the 2 groups were compared. RESULTS: The patients in the surgical group and those in the minimally invasive group showed similar results in success rate (both 97.5%). The procedure time, intensive care unit stay, hospital stay, and postoperative recovery time in the minimally invasive group were significantly shorter than those in the surgical group (58±21 minutes versus 145±26 minutes, 2±1 days versus 8±3 days, 5±1 days versus 16±6 days, 3±1 days versus 90±20 days, all P<0.05). The minimally invasive group had a higher incidence of conduction anomalies (17.5% versus 2.5%, P<0.05). In the follow-up period of 3-12 months, there was no new residual shunt, noticeable aortic regurgitation, significant arrhythmias, or device failure except for new complications in the surgical group. CONCLUSIONS: The success rate of minimally invasive perventricular device closure of VSD under transesophageal echocardiography guidance is similar to that of conventional surgical repair, but the short-term outcomes of the minimally invasive approach is much better. Long-term follow-up is necessary to confirm the effectiveness of this technique.

A biocleavable pullulan-based vector via ATRP for liver cell-targeting gene delivery.

Pullulan due to its specificity for liver has been widely exploited for biomedical applications. In this work, a tailor-made biocleavable pullulan-based gene vector (PuPGEA) with good hemocompatibility was successfully proposed via atom transfer radical polymerization (ATRP) for efficient liver cell-targeting gene delivery. A two-step method involving the reaction of hydroxyl groups of pullulan with cystamine was developed to introduce reduction-sensitive disulfide-linked initiation sites of ATRP onto pullulan. The poly(glycidyl methacrylate) (PGMA) side chains prepared subsequently via ATRP were functionalized with ethanolamine (EA) to produce the resultant biocleavable comb-shaped PuPGEA vectors consisting of nonionic pullulan backbones and disulfide-linked cationic EA-functionalized PGMA (PGEA) side chains with plentiful secondary amine and nonionic hydroxyl units. The cationic PGEA side chains can be readily cleavable from the pullulan backbones of PuPGEA under reducible conditions. Due to the liver targeting performance of pullulan backbones, such PuPGEA vectors exhibited much higher gene transfection efficiency and cellular uptake rates in HepG2 cell lines than in Hella cell lines. In addition, in vitro transfection efficiency and uptake mechanism of polyplex in HepG2 cells were evaluated in the presence of different endocytosis inhibitors, indicating that the asialoglycoprotein receptor was involved in transfection process of hepatocytes. More importantly, in comparison with gold standard polyethylenimine (PEI, ∼25 kDa), PuPGEA vectors possessed excellent hemocompatibility without causing undesirable hemolysis. Properly grafting short bioreducible PGEA polycation side chains from a liver cell-targeting pullulan backbone is an effective means to produce new hemocompatible polysaccharide-based gene delivery vectors.