Experience with a New Energy Source for Tissue Fusion in Pediatric Patients

Open versus Thoracoscopic RFA-Assisted Lung Resection

The purpose of this study was to evaluate Radio Frequency Ablation (RFA)-assisted lung parenchymal transection through thoracotomy and thoracoscopy. Twelve domestic pigs underwent RFA-assisted lingulectomy: six through thoracotomy (group A), and six with thoracoscopy (group B). There was no mortality, no bleeding, or air leak intra- or postoperatively in either of the groups, and no conversion to open thoracotomy in group B. Group A had longer operating period and more pleural adhesions. A barotrauma, a skin burn, and a localized infection were observed in this group. Histopathology confirmed a sharply demarcated area of coagulation necrosis without damage to adjacent structures. RFA-assisted lung resection through thoracotomy bears the inherent problems of an open approach, and the use of RFA device does not add to morbidity. The thoracoscopic use of RFA probe by experienced surgeons is considered safe, maintaining the advantages of key-hole surgery.

Randomized clinical trial comparing two vessel-sealing devices with crush clamping during liver transection

Background

Previous RCTs have failed to demonstrate the usefulness of combining energy devices with the conventional clamp crushing method to reduce blood loss during liver transection. Here, the combination of an ultrasonically activated device (UAD) and a bipolar vessel-sealing device (BVSD) with crush clamping was investigated.

Methods

Patients scheduled to undergo hepatectomy at the University of Tokyo Hospital or Nihon University Itabashi Hospital were eligible for this parallel-group, single-blinded randomized study. Patients were assigned to a control group (no energy device used), an UAD group or a BVSD group. The primary endpoint was the volume of blood loss during liver transection. Outcomes of the control group and the combined energy device groups (UAD plus BVSD) were first compared. Pairwise comparisons among the three groups were made for outcomes for which the combined energy device group was superior to the control group.

Results

A total of 380 patients were enrolled between July 2012 and May 2014; 116 patients in the control group, 122 in the UAD group and 123 in the BVSD group were included in the final analysis. Median blood loss during liver transection was lower in the combined energy device group (245 patients) than in the control group (116 patients): median 190 (range 0–3575) versus 230 (range 3–1570) ml (P = 0·048). Pairwise comparison revealed that blood loss was lower in the BVSD group than in the control group (P = 0·043).

Conclusion

The use of energy devices combined with crush clamping reduced blood loss during liver transection. Registration number: C000008372 (www.umin.ac.jp/ctr/index.htm).

Rationale, bench testing and in vivo evaluation of a novel 5 mm laparoscopic vessel sealing device with homogeneous pressure distribution in long instrument jaws

Background

In 1998, an electrothermal bipolar vessel sealing (EBVS) system was introduced and quickly became an integral component of the surgical armamentarium in various surgical specialties. Currently available EBVS instruments use a scissor-like jaw configuration and closing mechanism, which causes decreasing compression pressure from the proximal to the distal end of the jaws. A new EBVS system is described here which utilizes a different instrument jaw configuration and closing mechanism to enable a more homogeneous pressure distribution despite longer instrument jaws.

Methods

Results of jaw pressure distribution measurements as well as sealing experiments with subsequent burst pressure measurements ex vivo on bovine uterine arteries are demonstrated. Furthermore, an in vivo evaluation of the new EBVS system in a canine and porcine model including histological examination is presented.

Results

The device revealed an even pressure distribution throughout the whole jaw length. The ex vivo burst pressure measurements revealed high average burst pressures, above 300 mmHg, independent of the outer diameter (1 to 7 mm) of the tested vessels. Histological evaluation of sealed vessels 21 days postoperatively demonstrated sealed and fused vessels without adjacent tissue damage.

Conclusions

The even pressure distribution leading to a sufficient tissue sealing in combination with the novel closing mechanism and extended jaw length differentiates the novel device from other available EBVS systems. This might offer a reduction of the overall procedure time, which should be further evaluated in a clinical study.

Electrosurgical vessel sealing tissue temperature: experimental measurement and finite element modeling

The temporal and spatial tissue temperature profile in electrosurgical vessel sealing was experimentally measured and modeled using finite element modeling (FEM). Vessel sealing procedures are often performed near the neurovascular bundle and may cause collateral neural thermal damage. Therefore, the heat generated during electrosurgical vessel sealing is of concern among surgeons. Tissue temperature in an in vivo porcine femoral artery sealed using a bipolar electrosurgical device was studied. Three FEM techniques were incorporated to model the tissue evaporation, water loss, and fusion by manipulating the specific heat, electrical conductivity, and electrical contact resistance, respectively. These three techniques enable the FEM to accurately predict the vessel sealing tissue temperature profile. The averaged discrepancy between the experimentally measured temperature and the FEM predicted temperature at three thermistor locations is less than 7%. The maximum error is 23.9%. Effects of the three FEM techniques are also quantified.

Thoracoscopic segmentectomy for treatment of congenital lung malformations

PURPOSE

Congenital lung malformations (CLM) predispose patients to recurrent respiratory tract infections and pose a rare risk of malignant transformation. Although pulmonary lobectomy is the most common treatment of a CLM, some advocate segmental resection as a lung preservation strategy. Our study evaluated lung-preserving thoracoscopic segmentectomy as an alternative to lobectomy for CLM resection.

METHODS

We conducted a retrospective review of patients who underwent thoracoscopic segmentectomy for CLM from 2007 to 2010.

RESULTS

Fifteen patients underwent thoracoscopic segmentectomy for CLM. There were five postoperative complications: three asymptomatic pneumothoraces and a small air leak that resolved without intervention. One patient developed a bronchopulmonary fistula requiring thoracoscopic repair. At follow-up, all patients are asymptomatic. One patient has a small amount of residual disease on postoperative computed tomography (CT), and re-resection has been recommended.

CONCLUSIONS

Thoracoscopic segmentectomy for CLM is a safe and effective means of lung parenchymal preservation. The approach spares larger airway anatomy and has a complication rate that is comparable with that of thoracoscopic lobectomy. Residual disease can often only be appreciated on postoperative CT scan and may require long-term follow-up or reoperation in rare cases. This lung preservation technique is best suited to smaller lesions.