Ultrasonically Activated Device Research Articles

Modification of the Thermal Spread by the Blade Shape of an Ultrasonically Activated Device.

Few studies have focused on the spread of thermal damage from different blade shapes of ultrasonically activated devices (USADs) used during minimally invasive surgery. In vivo experiments using pig arteries, nerves, and mesentery were used to compare the thermal spread of two different blade types of USADs, non-tapered and tapered, under the same conditions. The tissue temperatures were monitored using a high-resolution infrared thermographic camera and calculated using an image analysis program. The spread of heat denaturation was measured histologically. The temperature was greater at the sides with greater curvature when non-tapered USADs were activated (artery, 1s, 2mm: - 0.92 ± 0.5°C vs. - 0.44 ± 0.5°C, P = 0.022). This effect was more prominent in the tapered type (artery, 1s, 0/1/2mm: 9.14 ± 3.7°C vs. 28.3 ± 16.2°C/0.5 ± 1.4°C vs. 9.76 ± 6.2°C/ - 0.12 ± 0.9°C vs. 1.44 ± 1.9°C, P = 0.044/0.016/0.038, respectively). The temperatures in the tapered USAD were significantly higher at some time- and distance-points than those in a non-tapered USAD (artery, 1s, 0mm, Less/1s, 1mm, Gre: 4.2 ± 2.9°C vs. 9.14 ± 3.7°C /0.36 ± 0.5°C vs. 9.76 ± 6.2°C, P = 0.047/0.027; nerve, 2s, 0mm, Gre: 6.54 ± 3.9°C vs. 17.66 ± 6.2°C, P = 0.012). A three-directional study revealed the thermal spread of the mesentery was greatest at the tip side of the non-tapered type USAD (4.55 ± 2.53°C vs. 12.43 ± 4.03°C/12.43 ± 4.03°C vs. 5.04 ± 1.91°C, P = 0.003/0.005). The thermal spread changed according to the blade shape of the USAD. This knowledge can be applied to more meticulous and complicated procedures, reducing surgical morbidity.

Repeated partial tissue bite with inadequate cooling time for an energy device may cause thermal injury.

Over the past three decades, the use of ultrasonically activated device (USAD) and advanced bipolar device (ABD) has grown in minimally invasive surgeries. However, the thermal profile differences during repeated dissection with different grasping ranges of energy devices, which provide valuable information for preventing thermal injury by energy devices, remain unclear. We developed an ex vivo benchtop model to examine the temperature profile of the blade and jaws of two USADs (HARMONIC® ACE + and Sonicision™) and a ABD (Ligasure™ Maryland) with different grasping ranges (partial tissue and full tissue bite) in repeated dissection with minimum cooling time. The maximum temperature, time required for completion to dissection of 10cm of porcine muscle, thermal spread, and cooling time to reach 60°C were continuously measured using video thermography. In addition, to evaluate one more grasping range "no tissue", we performed a stress test that activated the USAD without tissue intervention to assess the effects of excessive load on the blade and jaw. Repeated dissection of energy devices with minimal cooling time results in high blade and jaw temperatures proportional to the incision distance. In particular, the USADs with partial tissue bite showed a significantly higher temperatures at the blade and jaw, longer cooling times, and higher lateral thermal spread than those with a full tissue bite and the ABD. The stress test with a USAD showed an extremely high blade temperature exceeding 400°C, with the tissue pad melting only 13.2s after activation. Although USAD with partial tissue bite help ensure precise dissection, repeated long activation with inadequate cooling time may increase the risk of thermal injury during surgery. These results suggest that surgeons should use energy devices properly while understanding the risks of adjacent organ damage that could result from abuse of the device.

Emergent laparoscopic dome resection and omental suturing to the splenic parenchymal edge for a spontaneously ruptured non-parasitic large splenic cyst in a pediatric patient: a case report

BackgroundSpontaneously ruptured large splenic cyst is a rare in children, and traditionally total or partial splenectomy has been performed for treating an emergent case. We herein present a first case with spontaneously ruptured pediatric splenic cyst treated with emergent laparoscopic dome resection with omental suturing to the parenchymal edge of the spleen.Case presentationA 12-year-old girl with a spontaneously ruptured large non-parasitic splenic cyst (SC) was successfully treated by emergent laparoscopic dome resection with omental suturing to the edge of the splenic parenchyma. The patient presented with acute abdominal pain and was diagnosed with a ruptured non-parasitic SC and peritonitis by contrast-enhanced computed tomography (CT). Emergent laparoscopic dome resection of the SC and omental suturing to the splenic parenchymal edge were then performed. The protruding part of the cyst wall was completely resected using an ultrasonically activated device (USAD), and the greater omentum was then sutured to the anterior edge of the splenic parenchyma under a laparoscopic view. No complications were observed during the operation. A histological examination revealed a congenital splenic cyst lined by epithelial cells. The postoperative course was uneventful, and an ultrasound scan showed no evidence of cyst recurrence at 3 years after the operation.ConclusionsThis minimally invasive laparoscopic procedure was feasible and effective for treating a ruptured large splenic cyst in an emergent pediatric patient.

Intraoperative Pancreatic Injury Gives Rise to Severe Postoperative Pancreatic Fistula: Results of a Review of Unedited Videos of the Laparoscopic Surgical Procedures

Objective To examine risk factors for and causes of severe postoperative pancreatic fistula (sPOPF) after laparoscopic gastrectomy (LG). Summary of Background Data There are few reports on POPF after LG. Methods Between February 2012 and March 2014, we examined 86 patients who underwent LG, comparing them with 33 patients who underwent open gastrectomy (OG) for gastric cancer. Risk factors for severe POPF (sPOPF) of Clavien–Dindo grade IIIa or higher were examined. To investigate causes of sPOPF, we reviewed unedited video recordings of laparoscopic surgical procedures. Results sPOPF occurred in 3 patients (3.5%) after LG and 1 patient (3.0%) after OG, indicating no significant difference (P = 0.901). Univariate analysis showed no significant risk factors for sPOPF after LG. By reviewing video recordings, all 3 patients with sPOPF after LG had direct pancreatic injury by ultrasonically activated device (USAD) during peripancreatic lymphadenectomy. In 2 patients, pancreas was injured while the contour of pancreas was obscured by bleeding. Durations of drain placement and postoperative hospitalization were longer for patients with sPOPF than for those without POPF or grades I and II POPF (P = 0.003, 0.018; respectively). Conclusions No risk factors for sPOPF after LG could be identified. USAD-induced direct pancreatic injury resulted in sPOPF, which significantly complicated the postoperative clinical course. Direct pancreatic injury can occur whether patient has previously reported risk factors (i.e., male, high body mass index, distal pancreatectomy) or not. To prevent pancreatic injury, surgeons should manage hemostasis and keep good surgical field to recognize the contour of pancreas accurately.

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

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. 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. 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). 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).

Destruction of giant cluster-like vesicles by an ultrasonically activated device

In this paper, we propose a technically simple method of destroying a tissue marker composed of giant cluster-like vesicles (GCVs) to facilitate laparoscopic surgeries; the method releases various biological tracers contained in GCVs. An ultrasonically activated device (USAD) emitting 55.5 kHz ultrasound was employed for this purpose. Optical microscopy and fluorospectrophotometry revealed the destruction of GCVs after ultrasound irradiation when the blade tip was set 1.0 mm or closer to, but not directly in contact with, a GCV-containing cell. This means that USAD could be safely used for destroying this GCV tissue marker in clinical settings.

Efficacy of a half-grip technique using a fine tip LigaSure™, Dolphin Tip Sealer/Divider, on liver dissection in swine model.

BackgroundRecently, a lot of energy devices in the surgical field, especially in the liver surgery, have been developed, and a fine tip LigaSure™, Dolphin Tip Sealer/Divider (DT-SD) also has been used frequently to dissect liver parenchyma as well as ultrasonically activated device (USAD). However, the utility of this instrument for liver dissection (LD) is still unknown. Moreover, to reduce bleeding during LD, a half-grip technique (HGT) was contrived. We herein report an experimental study in swine model to evaluate the feasibility and effectiveness of HGT using DT-SD for LD.MethodsThe swine model experiment was carried out under general anesthesia by veterinarians. LD was performed repeatedly by DT-SD with the HGT (Group A, n = 6), or the conventional clamp-crush technique (CCT) (Group B, n = 6), and by variable mode USAD (Group C, n = 6). The dissection length and depth (cm) as well as bleeding volume (g) were measured carefully, and the dissection area (cm2) and speed (cm2/min) were calculated precisely. Histological examinations of the dissection surfaces were also executed. Mann–Whitney’s U test was used for Statistical analyses with variance at a significance level of 0.05.ResultsAmong the three groups, the three averages of dissection lengths were unexpectedly equalized to 8.3 cm. The dissection area (cm2) was 9.9 ± 5.1 in Group A, 9.8 ± 4.7 in Group B, and 9.9 ± 4.5 in Group C. The mean blood loss during LD was 10.6 ± 14.8 g in Group A, 41.4 ± 39.2 g in Group B, and 34.3 ± 39.2 g in Group C. For Group A, the bleeding rate was the least, 0.9 ± 1.0 g/cm2, and the average depth of coagulation was the thickest, 1.47 ± 0.29 mm, among the three groups (p < 0.05). The dissection speed in Group A (1.3 ± 0.3 cm2/min) was slower, than that in Group C (p < 0.05).ConclusionsThis report indicates firstly that the HGT using DT-SD bring the least blood loss when compared with CCT or USAD. Although the HGT is feasible and useful for LD, to popularize the HGT, further clinical studies will be needed.

Ablation of weak emphysematous visceral pleura by an ultrasonically activated device for spontaneous pneumothorax

Staple bullectomy is widely performed for the thoracoscopic treatment of spontaneous pneumothorax. When weak emphysematous change was observed to extend to the whole pleura around the localized bulla, weak emphysematous pleura always remain around the stapler after bullectomy. Such cases along with weak pleural surfaces around staplers belong to the groups at high risk of postoperative recurrence. We performed thoracoscopic ablation using an ultrasonically activated device (USAD) for such lesions and studied the efficacy. From April 2002 to December 2006, a total of 85 surgeries for spontaneous pneumothorax were performed in this hospital, of which 34 cases underwent ablation with a USAD for a weak pleural surface. No complications due to ablation were observed. Recurrence was observed in four subjects, but the cause of recurrence was the regeneration of a bulla outside the range of the ablation and was unrelated to the ablation itself. Moreover, significant white pleural thickening was observed at the ablation sites, demonstrating a stiffening effect of the weak visceral pleura. Ablation using a USAD is a safe and easy operative method, and it is an appropriate operative system as a stiffening procedure for a visceral pleura.

Development of an articulating ultrasonically activated device for laparoscopic surgery

Ultrasonically activated devices (USADs) offer excellent coagulating dissection performance and are broadly used, particularly in endoscopic operations. Traditional USADs, however, have fixed linear shape and are thus limited in the directions from which organs can be approached. We have developed a small USAD transducer attached to the tip of an articulating device, offering a new kind of USAD in which the tip can bend as desired. We describe herein an evaluation of the coagulating dissection performance of this new articulating USAD and an in vivo confirmation of clinical usefulness. To evaluate coagulating dissection performance, we compared coagulating shearing on porcine splenic arteries between the articulating USAD and a Harmonic Scalpel II (HSII), representing a traditional USAD. Changing the amplitude of vibration between 60 microm and 80 microm and grip force among 1, 2, and 3 N, we measured the time required for division and bursting pressure of coagulating dissection. An in vivo experiment in a pig was also used to confirm the usefulness of the articulating USAD in laparoscopic operations. Division time did not differ significantly between the articulating USAD and HSII with an 80-microm amplitude of vibration and a grip force of 2 or 3 N. Bursting pressure of blood vessels showed no significant difference between articulating USAD and HSII under all experimental conditions. In the in vivo experiment, the new bendable tip of the articulating USAD displayed coagulating dissection performance equivalent to that of the traditional USAD. We have developed a new articulating USAD that can broaden the range of methods and approaches available for USADs and improve usefulness and safety.

Three-Port laparoscopic partial hepatectomy using an ultrasonically activated device (USAD)

We provide an initial report of the indications and procedure for three-port laparoscopic partial hepatectomy. Three-port laparoscopic partial hepatectomy was performed in nine patients (age, 49 to 73 years) at our department. Eight patients (seven men and one woman) had hepatocellular carcinoma (HCC); six of these patients had liver cirrhosis (LC) and two had chronic hepatitis (CH). The ninth patient, a woman had a single metastatic liver tumor from colon cancer. The tumors were located in regons S(2), S(3), S(4), S(5), S(6), and S(8). Preoperative liver function assessment revealed Child-Pugh classification A or B. All the tumors were located superficially, and their diameter averaged approximately 3 cm. Hepatectomy was performed laparoscopically, using an ultrasonically activated device (USAD) with or without microwave coagulation therapy (MCT). The operative time was 50 to 168 min, and the intraoperative blood loss ranged from 32 to 158 g. The postoperative hospital stay was 5 to 17 days. No recurrences, including local relapse, were observed. Three-port laparoscopic partial hepatectomy is safe and feasible for patients with Child-Pugh liver function classification A or B if the tumor is located superficially and is less than 3 cm in diameter.

Bases fondamentales et pièges liés à l’utilisation des ciseaux ultrasoniques

In an ultrasonically activated device, electric energy is transformed to mechanical vibration, which is transmitted to the device’s tip. By clamping the vessel between the tissue pad and vibrating blade, frictional heat is generated. This heat, significantly milder than that in electrocautery technique, is ideal for sealing the vessel. The ultrasonic vibration eventually divides the vessel. In the experimental studies, the cut end of medium-sized vessels divided by a scissor type ultrasonically activated device (USAD) withstood high intravascular pressure. However, our clinical experiences with the USADs suggest there are pitfalls including: – giving excessive tension to the vessel, – incomplete clamping of the vessel, – contacting the adjacent vessel with the back side of the active blade tip, – contacting the adjacent vessel with the blade tip. Some devices are described to prevent these pitfalls.

How secure are the arteries occluded by a newly developed ultrasonically activated device?

We developed a new ultrasonically activated device (USAD) for endoscopic surgery. The current investigation was conducted to evaluate the security of the arteries occluded and divided by this USAD. The intraperitoneal arteries of anesthetized living pigs were individually occluded by the USAD at power levels of 70% or 100%. The burst pressures of the harvested arteries were measured in vitro. For comparison, arteries occluded by laparoscopic clips or silk ligatures were evaluated in the same manner. The pressures to burst the occluded artery ranged from 353 to 2,148 mmHg with an average of 1,204 mmHg in the USAD group at 70% power level; from 324 to 2,207 mmHg with an average of 1,193 mmHg in the USAD group at 100% power level; from 794 to 1,868 mmHg with an average of 1,421 mmHg in the clip group; and from 618 to 3,207 mmHg with an average of 1,586 mmHg in the silk ligature group. The data suggest the improbability that small- to medium-size arteries appropriately occluded and divided by the USAD can burst when exposed to intravascular pressures commonly found in living animals.

Ultrasonically-activated devices for endoscopic surgery

SummaryIn an ultrasonically-activated device (USAD), the controlled electric current is transformed into mechanical vibration in the transducer. The amplitude of this vibration is amplified in a conical metal horn, attached to the end of the transducer. The shaft of the USAD houses an extension rod, which transmits the amplified vibration to the end effecter. The end effecter in the scissor-type USAD is termed the ‘active blade’. The target tissue is clamped between the active blade and an opposed tissue pad, and effective coagulation occurs. In the USAD technique, frictional heat generated is mostly lower than boiling point, which allows collagens to denature with water and form a glue-like material to seal the vessel. Division of the tissue is caused mainly by ‘mechanical wear’ from the vibrating blade. Cavitation occurs at the tip of the active blade. As cavitation can be traumatic and fragment the tissue, any contact of the tip of the active blade with important tissue should be avoided. Recent reports on the USAD's ability to achieve haemostasis are excellent, suggesting that the cut-ends of the vessels withstand the high intraluminal pressure. However, the following four factors are considered pitfalls: the vessel could be divided before it is sufficiently occluded, due to excessive tension; the active blade could cross the vessel incompletely; adjacent vessels could be injured with the reverse side or the tip of the active blade.

Development of a 23.5 kHz ultrasonically activated device for laparoscopic surgery

SummaryWe tested, in an animal model, a newly developed ultrasonically activated device for laparoscopic use. Porcine arteries, with a diameter of 3 mm, were successfully coagulated and divided using this device. 11 segments of treated arteries were harvested and the pressure needed to burst the stump was measured in vitro. The maximum pressure required to burst the stump of an artery ranged from 353 to 2126 mmHg, with an average of 1121 mmHg. These data suggest that the arteries divided by the new device can withstand the intraluminal pressure of arteries in living animals. For a first clinical experience, we used this device in laparoscopic splenectomy, on a patient with idiopathic thrombocytopenic purpura. The short gastric vessels and branches of the main splenic vessels could be occluded and divided by the device without a clip. The main splenic vessels were cut using a stapler. The operation took 80 min, with a blood loss of ≤ 10 ml. Post-operative bleeding did not occur. The new, ultrasonically-activated device is a reliable instrument for occluding and dividing vessels of relatively small caliber. We conclude that this device is useful for a speedy and safe dissection of the tissue during laparoscopic surgery.