Hemostasis Plug for an Electromagnetic Thermotherapy and Its Application for Liver Laceration

Accident-induced liver trauma is a significant human health concern, as this organ is readily injured during periods at which the abdominal region is compromised. In this work, electromagnetic thermotherapy was successfully developed and employed in vitro and in vivo to treat livers that had been lacerated. Briefly, a new hemostasis plug was integrated with an electromagnetic thermotherapy system (ETS) to perform surgery on lacerated livers. The high-frequency, alternating electromagnetic field (EMF) was generated by the ETS and was shown to induce a pre-set temperature increase within the hemostasis plug embedded in the target tissue. In order to prevent overheating and maintain a constant hemostasis temperature, a temperature feedback control system was utilized. The effect of the intensity of the EMF on the heating capacity of the ETS-hemostasis system was first explored. Furthermore, the relationship between the coagulation zone and operating temperature were investigated in vitro. By utilizing the temperature feedback control system, the hemostasis plug could be heated to a specific temperature for efficient hemostasis. With this approach, the optimal treatment temperature and time were investigated for liver laceration. Lacerated livers from New Zealand white rabbits were successfully treated with the hemostasis plug and ETS within a short period of time. When compared with the traditional perihepatic packing approach, the volume of blood loss from liver laceration surgeries treated by ETS has been dramatically reduced by 83%, suggesting a high therapeutic potential for this system.

Electromagnetic thermotherapy for deep organ ablation by using a needle array under a synchronized-coil system

Thermal ablation by using electromagnetic thermotherapy (EMT) has been a promising cancer modality in recent years. It has relatively few side effects and has therefore been extensively investigated for a variety of medical applications in internal medicine and surgery. The EMT system applies a high-frequency alternating electromagnetic field to heat up the needles which are inserted into the target tumor to cause tumor ablation. In this study, a new synchronized-coil EMT system was demonstrated, which was equipped with two synchronized coils and magnetic field generators to provide a long-range, penetrated electromagnetic field to effectively heat up the needles. The heating effect of the needles at the center of the two coils was first explored. The newly designed two-section needle array combined with the synchronized-coil EMT system was thus demonstrated in the in vitro and in vivo animal experiments. Experimental data showed that the developed system is promising for minimally invasive surgery since it might provide superior performance for thermotherapy in cancer treatment.

Electromagnetic thermotherapy system with needle arrays: a practical tool for the removal of cancerous tumors

Thermotherapy has been a promising method to treat tumor. In recent years, electromagnetic thermotherapy (EMT) has been extensively investigated and holds the potential for a variety of medical applications including for cancer treatment when combined with minimally invasive surgery approach. In this study, an alternating electromagnetic frequency was provided by an EMT system to heat up stainless steel needle arrays which were inserted into the target tumor to a high temperature, therefore leading to local ablation of the tumor. A new two-section needle-array apparatus was further demonstrated to encompass the tumor to prevent the tumor cells to spread after the treatment process. By using the needle-array insertion apparatus, there is no limitation of the treatment area; this method could, therefore, be applied for tumors that are larger than 6 cm. It was first successfully demonstrated in the in vitro experiments on porcine livers. Then an in vivo experiment was directly conducted on pigs. The two-section needle array incorporated with the needle-array apparatus and EMT was demonstrated to be promising for no-touch isolation treatment of cancerous tumors.

Partial nephrectomy without renal ischemia using an electromagnetic thermal surgery system in a porcine model

OBJECTIVE

To test the feasibility of partial nephrectomy using needle arrays under alternating current (AC) electromagnetic field without renal artery clamping.

METHODS

We performed an experimental study for partial nephrectomy without renal artery clamping in a porcine model, comparing a new thermal surgery system consisting of an AC electromagnetic field generator and stainless steel needle arrays (using 10 pigs) vs an ultrasonic Harmonic Scalpel (on 8 pigs). Two cm of the upper pole of the kidneys were resected, and then the feasibility, operation time, blood loss, biochemical parameters, pathology, and complications were observed for 14 days.

RESULTS

There was no difference by weight in the mean percentage of kidney removed between the 2 groups (8.1 ± 3.4% vs 12.7 ± 5.5%). The estimated blood loss for the partial nephrectomy with electromagnetic thermal surgery system was significantly less compared to the ultrasonic Harmonic Scalpel (53.0 ± 73.0 vs 188.8 ± 49.3 mL). Transection time was shorter with the electromagnetic thermal surgery system (10 vs 12 minutes). Bleeding from the cut surface after partial nephrectomy was noted in 2 pigs (electromagnetic surgery group) and 8 pigs (control group); all the bleeding was controlled with additional monopolar electrocoagulation and sutures. No urinoma was identified in either group when a second laparotomy was performed 2 weeks later.

CONCLUSION

Our study of a partial nephrectomy in a porcine model demonstrates that the heat generated by the electromagnetic thermal surgery system is sufficient to coagulate renal parenchyma and to seal off the blood vessels without pedicle clamping.

Successfully Seal Pancreatic End After Thermal Distal Pancreatectomy Using Needle Arrays in Alternating Electromagnetic Fields

Background. Pancreatic fistula is still the major postoperative morbidity after distal pancreatectomy (DP). An inductive heat technology via needle arrays in a system of alternating magnetic fields (AMFs) was designed to seal off the pancreatic end. Methods. Twenty Lanyu pigs were divided into 2 groups for DP: the conventional group had hand-sewn closure of the pancreatic end (n = 10), and the AMF group received thermal DP by AMF (n = 10). Pathological examinations of the resected and remnant pancreas were studied immediately after resection and on the 14th postoperative day (POD), respectively. The severity and the incidence of pancreatic abscess were compared. Results. The incidence and severity of pancreatic abscess were significantly decreased in the AMF group than those in the conventional group ( P = .009). In the immediate postoperative period, microscopic examination of the pancreatic resected end showed prominent coagulative necrosis, loss of NADPH-diaphorase activity, and significant apoptosis at the resected pancreas in the AMF group compared with the control group. Fourteen days after AMF ablation, the pancreatic stump end was covered with thick fibrosis, and histological study of the remnant pancreas showed that the parenchyma had well recovered with positive NADPH-diaphorase activity, and the pancreatic duct was sealed off successfully by prominent periductal fibrosis and intraductal plug. The body weight gain on the 14th POD was significantly increased in the AMF group (from 23.8 ± 1.8 kg to 25.4 ± 5.5 kg) compared with the conventional group (from 25.3 ± 2.1 to 25.4 ± 6.0 kg; P = .003). Conclusions. Inductive heats by the AMF system via needle array can be performed easily and can seal the pancreatic cut surface well during DP.

Dual-row needle arrays under an electromagnetic thermotherapy system for bloodless liver resection surgery

Electromagnetic thermotherapy has been extensively investigated recently and may become a new surgical modality for a variety of medical applications. It applies a high-frequency alternating magnetic field to heat up magnetic materials inserted within the human body to generate tissue coagulation or cell apoptosis. Using a new procedure with dual-row needle arrays under an electromagnetic thermotherapy system with a feedback temperature control system, this study demonstrates bloodless porcine liver resection, which is challenging using existing methods. In vitro experiments showed that hollowed, stainless-steel needles could be heated up to more than 300 °C within 30 s when centered under the induction coils of the electromagnetic thermotherapy system. In order to generate a wide ablation zone and to prevent the dual-row needle arrays from sticking to the tissue after heating, a constant temperature of 120 °C was applied using a specific treatment protocol. The temperature distribution in the porcine livers was also measured to explore the effective coagulation area. Liver resection was then performed in Lan-Yu pigs. Experimental results showed that seven pigs underwent liver resection without bleeding during surgery and no complications afterward. The dual-row needle arrays combined with the electromagnetic thermotherapy system are thus shown to be promising for bloodless tissue resection.

Partial splenectomy using an electromagnetic thermal surgery system in a porcine model

PURPOSE

Partial splenectomy is technically more complicated than total splenectomy due to difficulty in haemostasis, but it can preserve splenic function after operation. We evaluated the feasibility and safety of partial splenectomy performed by an electromagnetic thermal surgery system in a porcine model.

METHODS

Our system was comprised of an alternating electromagnetic field generator, an extensible coil applicator, comb-needle arrays, and a temperature feedback control component. Ten Lanyu pigs were anaesthetised to conduct partial splenectomy. Two rows of comb-like stainless-steel needle arrays were inserted into the tissue at 15 cm from the distal tip of the spleen. The temperature of the tissues around the needle arrays was raised to 150°C for 3 min and the spleen was transected directly between the needle arrays and then sent for histological examination. Two weeks later, the animals underwent a second celiotomy to remove the remaining spleen for histological examination.

RESULTS

The average duration of the partial splenectomy was 10 min as timed from insertion of the needle arrays to the transection of the spleen. There was no blood loss during the procedure. The cut surface of the spleen was well coagulated without any oozing sites. During the re-exploration, no intra-abdominal blood was found. There were dense adhesions between the spleen and the surrounding organs. Histological examination of the cut surface of the excised portion of the spleen showed coagulative necrosis with clot formation in the blood vessels.

CONCLUSIONS

Partial splenectomy using our electromagnetic thermal system can achieve effective haemostasis and is safe and easy to perform.