A radiofrequency-assisted device for bloodless rapid transection of the liver: A comparative study in a pig liver model

The impact of additional margin coagulation with radiofrequency in liver resections with subcentimetric margin: can we improve the oncological results? A propensity score matching study

BACKGROUND

Whereas the usefulness of radiofrequency (RF) energy as haemostatic method in liver surgery has become well established in the last decades, its intentional application on resection margins with the aim of reducing local recurrence is still debatable. Our goal was to compare the impact of an additional application of RF energy on the top of the resection surface, namely additional margin coagulation (AMC), on local recurrence (LR) when subjected to a subcentimeter margin.

METHODS

We retrospectively analyzed 185 patients out of a whole cohort of 283 patients who underwent radical hepatic resection with subcentimetric margin. After propensity score adjustment, patients were classified into two balanced groups according to whether RF was applied or not.

RESULTS

No significant differences were observed within groups in baseline characteristics after PSM adjustment. The LR rate was significantly higher in the Control than AMC Group: 12 patients (14.5%) vs. 4 patients (4.8%) (p = 0.039). The estimated 1, 3, and 5-year LR-free survival rates of patients in the Control and AMC Group were: 93.5%, 86.0%, 81.0% and 98.8%, 97.2%, 91.9%, respectively (p = 0.049). Univariate Cox analyses indicated that the use of the RF applicator was significantly associated with lower LR (HR = 0.29, 95% confidence interval 0.093-0.906, p = 0.033). The Control Group showed smaller coagulation widths than the AMC group (p < 0.001).

CONCLUSIONS

An additional application of RF on the top of the resection surface is associated with less local hepatic recurrence than the use of conventional techniques.

Impact of monopolar radiofrequency coagulation on intraoperative blood loss during liver resection: a prospective randomised controlled trial

PURPOSE

To evaluate the impact of using monopolar thermal coagulation based on radiofrequency (RF) currents on intraoperative blood loss during liver resection.

MATERIALS AND METHODS

A prospective randomised controlled trial was planned. Patients undergoing hepatectomy were randomised into two groups. In the control group (n = 10), hemostasis was obtained with a combination of stitches, vessel-sealing bipolar RF systems, sutures or clips. In the monopolar radiofrequency coagulation (MRFC) group (n = 18), hemostasis was mainly obtained using an internally cooled monopolar RF electrode.

RESULTS

No differences in demographic or clinical characteristics were found between groups. Mean blood loss during liver resection in the control group was more than twice that of the MRFC group (556 ± 471 ml vs. 225 ± 313 ml, p = .02). The adjusted mean bleeding/transection area was also significantly higher in the control group (7.0 ± 3.3 ml/cm² vs. 2.8 ± 4.0 ml/cm², p = .006). No significant differences were observed in the rate of complications between the groups.

CONCLUSIONS

The findings suggest that the monopolar electrocoagulation created with an internally cooled RF electrode considerably reduces intraoperative blood loss during liver resection.

Laparoscopic partial splenectomy for giant cyst using a radiofrequency-assisted device: a case report

Background

Although radiofrequency-assisted devices have sometimes been used in partial splenectomy, this is not a common technique. This report describes the first case of laparoscopic partial splenectomy using an RF-assisted device (Coolinside) which allows both coagulation and transection of the parenchyma and eventually the protective coagulation of the remnant side.

Case presentation

A 27-year-old woman was found to have a giant hydatic cyst measuring 12.0 × 14.0 × 16.6 cm that mainly occupied the lower pole of the spleen and retroperitoneal space. The patient underwent a laparoscopic partial splenectomy using an RF-based device designed to accomplish both the coagulation and dissection of the splenic tissue. The estimated blood loss was less than 200 mL.

Conclusions

Even though RF ablation has traditionally been used for hepatic parenchymal transection, it seems equally suited to partial splenectomy. This device seems to provide good results, minimizing blood loss during partial splenectomy; however, randomized trials will be necessary to see if the results are superior to those of other techniques.

Radiofrequency pancreatic ablation and section of the main pancreatic duct does not lead to necrotizing pancreatitis

OBJECTIVE

The aim of this study was to determine whether radiofrequency ablation (RFA) of the pancreas and subsequent transection of the main pancreatic duct may avoid the risk of both necrotizing pancreatitis and postoperative pancreatic fistula (POPF) formation.

METHODS

Thirty-two rats were subjected to RFA and section of the pancreas over their portal vein. Animals were killed at 3, 7, 15, and 21 days (groups 0-3, respectively). Two additional control groups (sham operation and user manipulation only, respectively) of 15 days of postoperative period were considered. Postoperative complications, histological changes (including morphometric and immunohistochemical analysis), and incidence of POPF were evaluated.

RESULTS

A significant increase in serum amylase levels (P < 0.05) on the third postoperative day, which return to baseline levels in the following weeks, was noted in groups 0 to 3. Those groups showed a rapid atrophy of the distal pancreas by apoptosis with no signs of necrotizing pancreatitis or POPF. The distal pancreas in groups 1 to 3 compared with group 0 and control groups showed a significant increase of small islets (<1000 µm).

CONCLUSIONS

The rapid acinar atrophy of the distal pancreas after RFA and section of the pancreatic ducts in this model does not lead to necrotizing pancreatitis.

[Sutureless hepatic transection using a new radiofrequency assisted device. Theoretical model, experimental study and clinic trial]

The ideal instrument for performing hepatic transection should combine safe and rapid haemostasis in a single tool. We present a new multidisciplinary investigation designed to develop a hepatic transection device assisted by radiofrequency (RF); the investigation included: a computerised theoretical model, and experimental study and a clinical trial of this device. The theoretic modelling was performed by computer, based on the Finite Elements Method (FEM), with the objective of studying the distribution of electrical energy and temperature in the tissue, and to assess the effect of the characteristics of the instrument. The experimental study, based on an in vivo porcine model, suggested that the new instrument would allow the transection velocity of the hepatic parenchyma to be increased with lower bleeding per transection area compared with other techniques extensively used in liver surgery. These data should enable the first phase of clinical trial to be conducted, with preliminary results that suggest that the new device is safe and effective.

Research and development of a new RF-assisted device for bloodless rapid transection of the liver: computational modeling and in vivo experiments

Background

Efficient and safe transection of biological tissue in liver surgery is strongly dependent on the ability to address both parenchymal division and hemostasis simultaneously. In addition to the conventional clamp crushing or finger fracture methods other techniques based on radiofrequency (RF) currents have been extensively employed to reduce intraoperative blood loss. In this paper we present our broad research plan for a new RF-assisted device for bloodless, rapid resection of the liver.

Methods

Our research plan includes computer modeling and in vivo studies. Computer modeling was based on the Finite Element Method (FEM) and allowed us to estimate the distribution of electrical power deposited in the tissue, along with assessing the effect of the characteristics of the device on the temperature profiles. Studies based on in vivo pig liver models provided a comparison of the performance of the new device with other techniques (saline-linked technology) currently employed in clinical practice. Finally, the plan includes a pilot clinical trial, in which both the new device and the accessory equipment are seen to comply with all safety requirements.

Results

The FEM results showed a high electrical gradient around the tip of the blade, responsible for the maximal increase of temperature at that point, where temperature reached 100°C in only 3.85 s. Other hot points with lower temperatures were located at the proximal edge of the device. Additional simulations with an electrically insulated blade produced more uniform and larger lesions (assessed as the 55°C isotherm) than the electrically conducting blade. The in vivo study, in turn, showed greater transection speed (3 ± 0 and 3 ± 1 cm²/min for the new device in the open and laparoscopic approaches respectively) and also lower blood loss (70 ± 74 and 26 ± 34 mL) during transection of the liver, as compared to saline-linked technology (2 ± 1 cm²/min with P = 0.002, and 527 ± 273 mL with P = 0.001).

Conclusion

A new RF-assisted device for bloodless, rapid liver resection was designed, built and tested. The results demonstrate the potential advantages of this device over others currently employed.