A novel spleen-preserving laparoscopic technique using radiofrequency ablation in a porcine model

Partial spleen resection with a radiofrequency needle device--a pilot study

INTRODUCTION

Total splenectomy leads to an immunocompromised state, with an increased lifetime risk of infection. The lifetime risk of developing overwhelming postsplenectomy infection is 5 %, with a mortality rate of approximately 50 %. In addition to vaccination and antibiotic prophylaxis, partial splenectomy is believed to improve patient safety.

METHODS

We performed partial splenectomy in seven patients using a radiofrequency (RF) technique with Habib® needles. In seven patients, an open access partial splenectomy was performed. In three patients, a partial splenectomy was performed simultaneously with intraabdominal tumour resection. In two patients, the upper pole of the spleen was removed due to tumours of the spleen. In one patient, a large symptomatic splenic cyst was resected and in another patient, a partial splenectomy was performed due to trauma. RF was applied using Habib® needles (AngioDynamics, Manchester, GA, 31816, USA).

RESULTS

The partial splenectomy procedures were easy and safe in all seven patients. The RF application with the Habib® needles led to primary haemostasis. The blood loss was less than 50 ml in all cases. After a minimum follow-up of 1 year, there were no cases of infections or other adverse events related to the previous partial splenectomy.

CONCLUSION

In our experience, partial splenectomy with Habib® needles is easy to perform and safe for the patient. Thus, radiofrequency resection is a good alternative to total splenectomy in many patients and reduces the risk of postsplenectomy infections.

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.

915MHz microwave ablation with high output power in in vivo porcine spleens

OBJECTIVE

The purpose of this study was to evaluate the efficacy of 915 MHz microwave (MW) ablation with high output power in in vivo porcine spleens.

MATERIALS AND METHODS

MW ablations were performed in 9 porcine spleens with an internally cooled 915 MHz antenna. Thermocouples were placed at 5, 10, 15, 20 mm away from the antenna to measure temperatures in real-time during MW emission. The energy was applied for 10 min at high output power of 60 W, 70 W or 80 W. Gross specimens were sectioned and measured to determine ablation size. Representative areas were examined by light microscopy and electron microscopy. Coagulation sizes and temperatures were compared among the three power groups.

RESULTS

Hematoxylin-eosin staining showed irreversible necrosis in the splenic coagulation area after MW ablation. As the power was increased, long-axis diameter enlarged significantly (p<.05). Short-axis diameter also tended to increase, but there were no statistical difference (p>.05). The coagulation size of long-axis and short-axis diameter with 80 W in vivo spleen ablation was 6.43+/-0.52 and 4.95+/-0.30 cm, respectively. With the increase of output power, maximum temperatures at 5, 10, 15, 20 mm from the antenna were increased accordingly (p<.05). The maximum temperature with 80 W at 5 and 20 mm from the antenna reached 146.17+/-6.65 and 72.38+/-4.23 degrees C respectively.

CONCLUSION

With internally cooled antenna and high output power, 915 MHz MW ablation in the spleen could produce irreversible tissue necrosis of clinical significance. MW ablation may be used as a promising minimally invasive method for the treatment of splenic diseases.

Laparoscopic partial splenectomy using radiofrequency ablation

INTRODUCTION

Epidermoid cysts are believed to be congenital in origin and often present in the pediatric population. Because of the concerns of compromised immunologic function after total splenectomy and increasing demand for minimally invasive approaches, interest has increased in performing the partial splenectomy in this patient population by laparoscopic techniques. Nonetheless, concerns for adequate hemostasis have limited its widespread adoption. Because radiofrequency ablation for the partial splenectomy has been done in a laparoscopic porcine model with good results, we used this technology with the goal of limiting blood loss and postoperative hemorrhagic complications.

CASE REPORT

A 25-year-old female presented with complaints of right shoulder pain. Abdominal ultrasound and a computed tomography (CT) scan revealed a 10-cm cystic lesion of the spleen. Serology was negative for hydatid cyst pathology. The patient underwent an uneventful partial splenectomy by minimally invasive techniques with the aid of a laparoscopic radiofrequency ablative device and the placement of a hemostatic medicated sponge along the line of transection.

RESULTS

Estimated blood loss was less than 30 mL. Final pathology was consistent with an epidermoid splenic cyst, and the patient was discharged uneventfully on postoperative day 5.

DISCUSSION

Techniques for the treatment of symptomatic splenic cysts range from total splenectomy to cyst fenestration and placement of the omentum in the splenic defect. The use of radiofrequency ablation has been traditionally used for hepatic parenchymal transection but seems equally suited for the partial splenectomy. This technology, and the addition of hemostatic sponges, seems to provide excellent results in minimizing blood loss, intraoperatively and postoperatively, during the laparoscopic partial splenectomy; however, randomized, prospective trials will be necessary to see if they will be superior to traditional techniques.

Video-assisted lung resection using radiofrequency ablation in a porcine model

BACKGROUND

The aim of this study was to assess the feasibility, efficacy, and safety of video-assisted lingula resection using radiofrequency ablation (RFA) with internally cooled electrodes in a porcine model.

MATERIALS AND METHODS

Six domestic pigs underwent RFA-assisted thoracoscopic lingulectomy. RFA was the only aerostatic and hemostatic method applied throughout the operation. After 30 d, the animals were sacrificed for the study of the macroscopic and microscopic effects of the technique.

RESULTS

No signs of pneumothorax, blood loss, or infection were observed up to 1 mo postoperatively. There was no mortality either during or after surgery. The histopathology of the lung revealed three clearly demarcated zone lesions.

CONCLUSIONS

Our study demonstrates that thoracoscopic lingulectomy using RFA energy is technically feasible. RFA energy is an effective and safe aerostatic and hemostatic method in the porcine model.

Liver tissue dissection: ultrasonic or RFA energy?

BACKGROUND

Hepatic resection is the only potential curative treatment for a wide variety of conditions. However, liver surgery is technically demanding and closely associated with a number of serious complications. New devices and techniques are currently being applied in practice, which will improve the surgical outcome.

METHODS

This retrospective study compares two methods of liver parenchymal division: ultrasound energy, a modern but already widely used technique, and radio-frequency ablation (RFA), a completely novel method. The parameters investigated include the amount of blood transfused, the necessity of the Pringle maneuver, the length of time required for parenchymal division, and postoperative morbidity and mortality. The patients were divided into two groups. In one group (Group A), 15 patients underwent 17 ultrasound-assisted liver resections, in which ten metastatic tumors, six hepatomas, and one cholangiocarcinoma were resected. In Group B, 21 patients underwent 22 RFA-assisted hepatectomies in which 11 metastatic tumors, ten hepatomas, and two cholangiocarcinomas were removed.

RESULTS

Thirteen patients (87%) in Group A and 11 (52%) in Group B received a transfusion, with an average of 3.5 and 1.6 units of red blood cells, respectively. The Pringle maneuver was necessary in two cases in Group A but was unnecessary in Group B. The mean length of time required for parenchymal dissection was 124 min in Group A and 93.18 min in Group B. One (6.7%) and four (19%) complications were observed in Group A and B, respectively (statistically not significant). Mortality remained zero in both groups.

CONCLUSIONS

RFA energy provides a novel reliable and safe alternative that can be used exclusively or as a supplement to the older techniques. Both resection time and amount of blood transfusion were reduced in the RFA group.

CT-guided percutaneous radiofrequency ablation of spleen: a preliminary study

OBJECTIVE

The objective of our study was to evaluate the technical feasibility, safety, and changes of platelet counts of CT-guided percutaneous radiofrequency ablation of normal spleen in a porcine model.

CONCLUSION

It is feasible and safe to perform CT-guided percutaneous radiofrequency ablation of the spleen in a pig. Although further study is still required in clinical applications, this method can be a minimally invasive and effective therapeutic technique in patients with hypersplenism.

Radio Frequency Ablation (RFA)-assisted Pericystectomy for Hepatic Echinococcosis

The aim of this study is to describe an alternative technique, using radio frequency energy to perform pericystectomy for hepatic echinococcosis. We present 3 patients with hepatic echinococcosis who were treated with radio frequency ablation (RFA)-assisted pericystectomy. A Radionics Cooltip Radio Frequency System (Tyco, Greece, Radionics) with a single shaft 15 cm long needle electrode and a 2 cm exposure tip, was used. The needle electrode was inserted in consecutive sites into the "healthy" hepatic parenchyma close to the cyst wall, so that a tissue zone around the cystic cavity was gradually ablated. The complete ablation of a site was followed by sharp division of the parenchyma. The operation completed successfully in all patients. Minor bleeding and/or bile leakage were successfully controlled with RFA coagulation. No other hemostatic method was used. The postoperative course was uneventful. No evidence of recurrent disease, or any other cause of morbidity, has been demonstrated at follow up (2 y). RFA-assisted pericystectomy for hepatic hydatid disease in experienced hands, might be useful to perform a "sterile" resection, eradicating single or multiple cysts and preventing local recurrence, with minimal morbidity.