BACKGROUNDThe aim of this research was to evaluate the feasibility and efficacy of absorbable bandage wrapping in the treatment of cases of severe liver trauma.

METHODSElectric firecrackers were detonated in 16 miniature swine to produce a severe blast liver injury. After fluid resuscitation, the animals were randomly divided into two groups (n = 8 each) and were either treated with absorbable bandage wrapping of the injured lobe of liver (Group B) or hepatic lobectomy (Group H). Time to hemostasis, blood loss during the treatment period, and other parameters were compared, including postoperative serum total bilirubin (TB), alanine aminotransferase (ALT), and aspartate aminotransferase (AST).

RESULTSBlood loss during the treatment period was significantly lower in Group B than that in Group H ((81.3 ± 26.0) ml vs. (130.8 ± 29.5) ml, P = 0.0031). Serum AST and ALT were transiently increased post-surgically. These transient increases were significantly higher in Group B. No difference in time to hemostasis was noted ((8.70 ± 2.27) minutes vs. (10.28 ± 1.93) minutes, P = 0.1559) in Groups B and H, respectively. Two pigs were humanely euthanized 28 days post-surgically and the wrapped liver lobes appeared atrophies. Microscopically, there was evidence of emerging and mature fibrous tissue.

CONCLUSIONAbsorbable bandage wrapping is both feasible and effective in the treatment of severe blast liver injury.

Animals ; Bandages ; Female ; Liver ; injuries ; surgery ; Male ; Swine ; Swine, Miniature

BACKGROUNDImaging-guided thermal ablation using different energy sources continues to gain favor as a minimally invasive technique for the treatment of primary and metastatic hepatic malignant tumors. This study aimed to evaluate the performance of microwave ablation with 2450-MHz internally cooled-shaft antenna in ex vivo and in vivo porcine livers.

METHODSAll studies were animal care and ethics committee approved. Microwave ablation was performed using a noncooled or cooled-shaft antenna in 23 ex vivo (92 ablations) and eight in vivo (36 ablations) porcine livers. Diameters of the coagulation zone were observed on gross specimens. The coagulation diameters achieved in different microwave ablation parameter groups were compared. Curve estimation analysis was performed to characterize the relationship between applied power and treatment duration and coagulation diameter (including short-axis and long-axis diameter).

RESULTSCoagulation zones were elliptical and an arrowed-shaped carbonization zone around the shaft was observed in all groups. But the antenna track was also coagulated in the noncooled-shaft antenna groups. In ex vivo livers, the short-axis diameter correlated with the power output in a quadratic curve fashion (R(2) = 0.95) by fixing ablation duration to 10 minutes, and correlated with the ablation duration in a logarithmic curve fashion (R(2) = 0.98) by fixing power output to 80 W. The short-axis reached a relative plateau within 25 minutes. In in vivo livers, short-axis diameter correlated with the coagulation duration in a sigmoidal curve fashion (60 W group R(2) = 0.76, 80 W group R(2) = 0.87), with a relative plateau achieved within 10 minutes for power settings of 60 W and 80 W.

CONCLUSIONSThe internally cooled microwave antenna may be advantageous to minimize collateral damage. The short-axis diameter enlargement has a plateau by fixing power output.

Animals ; Catheter Ablation ; Liver ; surgery ; Microwaves ; Swine

OBJECTIVETo study the influences on mandibular development after removing the outer cortex of mandibular body in childhood minitype pig.

METHODSSix childhood minitype pigs were selected as the experimental animals. The outer cortex of mandibular body measured as 3.0 cm x 1.5 cm was removed in one side, and the other side remained intact as the control. The changes of mandibular modality and occlusion relationship as well as the histological and biomechanical changes were studied 24 weeks after operation.

RESULTSThere was no obvious difference compared with the control side in the height of the mandibular ramus and the length of the mandibular body, However, lateral deviation occlusion was found in some animals. The body thickness was thinner than that of the control side, there were no obvious biomechanical and histological differences between the two sides.

CONCLUSIONSThere was less influence on the growth of mandibular bone after removing one side of the outer cortex of the mandibular body in childhood minitype pig. But further study should be done for the cause of the lateral deviation of the mandible in part of the animals.

Animals ; Female ; Male ; Mandible ; growth & development ; surgery ; Mandibular Condyle ; surgery ; Osteotomy ; adverse effects ; Swine ; Swine, Miniature

A purely laparoscopic four-port approach was created for left hepatectomy in pigs. A polyethylene loop was placed on the left two hepatic lobes for traction and lift. Next, penetrating ligation of the lobes using of a double row of silk sutures was performed to control bleeding. A direct hepatic transection was completed using a monopolar hook electrode without meticulous dissection of the left hepatic vein. The raw surface of the liver was coagulated and sealed with fibrin glue. Lobes were retrieved through an enlarged portal. Laparoscopic hepatic lobectomy was completed in all pigs without the use of specialized instruments and with a mean operative time of 179 +/- 9 min. No significant perioperative complications were observed. The average weight of each resected lobe was 180 +/- 51 g. Complete blood count as well as serum organics and enzyme levels normalized after about 2 weeks. During necropsy, adhesion of the hepatic raw surface to the gastric wall and omentum were observed. No other abnormalities were identified. This minimally invasive left hepatectomy technique in swine could serve as a useful model for investigating liver diseases and regeneration, and offer preclinical information to improve hepatobiliary surgical procedures.
Animals ; Female ; Hepatectomy/methods/*veterinary ; Laparoscopy/methods/veterinary ; Liver/surgery ; Male ; Postoperative Care/methods/veterinary ; Swine/*surgery ; Swine, Miniature/surgery

OBJECTIVETo study the efficacy, safety and reliability of colonic sac duct for first-stage repair of colorectal anastomotic leakage.

METHODSAn animal model of colon anastomotic leakage was established in 30 Tibet miniature pigs, which were randomly divided into treatment group and control group (n=15). Colon anastomotic leakage in the treatment group was repaired using the colonic sac duct, while the control group received conventional surgical repair. At 7, 14, and 21 days after the surgery, the healing of the anastomotic leakage was evaluated by examining the bursting pressure, tissue microvessel density and hydroxyproline content at the anastomosis.

RESULTSUsing the colonic sac duct, the anastomotic leakage was successfully repaired without death of the pigs or the occurrence of intestinal stenosis or necrosis. At 7 and 14 days after the surgery, the bursting pressure, hydroxyproline contents, and microvessel density in the treatment groups were higher than those in the control group, but such difference was not found at 21 days.

CONCLUSIONColonic sac duct allows effective repair of colon anastomotic leakage, and is especially useful for leakage lasting for 48-72 h complicated by severe abdominal infection.

Anastomosis, Surgical ; adverse effects ; Anastomotic Leak ; etiology ; surgery ; Animals ; Colon ; surgery ; Female ; Male ; Rectum ; surgery ; Swine ; Swine, Miniature

OBJECTIVETo investigate the change of morphology, biomechanics and histology after osteotomy of mandibular outer cortex.

METHODSThe mandibular outer cortex that involves angle and part of body was removed at one side in 8 minitype pigs aged 8-12 months. 2 pigs were selected randomly for histologic examination 12 weeks after operation. The other 6 animals were killed 24 weeks after operation. The thickness of new-formed mandibular outer cortex was measured and compared with that of operated side. Biomechanical test was performed in bilateral angles. Histological observation was made in the operated side.

RESULTSThe thickness of outer cortex was (2.1 +/- 0.3) mm and (2.5 +/- 0.4) mm in the operated side and opposite side, respectively, showing a significant difference between them (P < 0.01). The maximum load was (401.76 +/- 204.91) N and (585.42 +/- 413.07) N in the operated side and opposite side, respectively (P > 0.05). The Rigidity was (2172.19 +/- 1174.73) N/mm and (2363.90 +/- 1547.48) N/mm (P > 0.05). There was no statistical difference in biomechanics between the two sides. The histologic study showed histologically complete regeneration of outer cortex 24 weeks after mandibular outer cortex osteotomy.

CONCLUSIONSAfter resection of mandibular outer cortex, the histologic restoration is complete, but the new-formed outer cortex is thinner with local depression. Bone tubercle can be seen at the angle after bone regeneration. There is no obvious change in biomechanics after outer cortex osteotomy.

Animals ; Biomechanical Phenomena ; Female ; Male ; Mandible ; surgery ; Osteotomy ; methods ; Swine ; Swine, Miniature

OBJECTIVETo establish a animal model of biliary leakage in pigs with laparoscopy.

METHODSEight healthy Bama minipigs were subject to laparoscopic surgery under general anesthesia.The cystic duct was resected at 0.5-1.0 cm from the root and the stump was left open with the gallbladder removed. Blood routine and hepatic functions of the pigs were tested before and 24 h after the surgery, and endoscopic retrograde cholangiography (ERC) was performed 24 h after the surgery. At 48 h after the surgery, the pigs were sacrificed for observation of the stump of the cystic duct.

RESULTSThe gallbladder, cystic duct, cystic artery, and the anatomical relations between the gallbladder and liver and between the cystic duct and common bile duct were fully exposed under laparoscopy. White blood cells, neutrophils and direct bilirubin increased significantly after the operation (P<0.05). The cystic ducts were resected at 0.5-1 cm away from the roots of the cystic ducts in 7 pigs and at 2 cm in 1 pig.

CONCLUSIONLaparoscopy is safe and feasible for establishing the porcine model of biliary leakage.

Animals ; Biliary Fistula ; Cystic Duct ; surgery ; Disease Models, Animal ; Female ; Laparoscopy ; Male ; Swine ; Swine, Miniature

OBJECTIVETo investigate the local changes of biomechanics after osteotomy of mandibular outer cortex in body and angle areas.

METHODSSix minitype pigs at the age of 8 to 12 months were selected. The mandibular outer cortex that involves angle and part of body was removed in one side. The animals were killed 24 weeks after operation. Bone strut was taken from mandibular angle region bilaterally and sent for biomechanical test

RESULTSThere was no biomechanical difference between the two angle areas of experimental and normal sides 24 weeks after mandibular outer cortex osteotomy (maximum load P > 0.05, rigidity P > 0.05).

CONCLUSIONSMandibular outer cortex osteotomy had no influence on local biomechanics.

Animals ; Biomechanical Phenomena ; Female ; Male ; Mandible ; physiology ; surgery ; Osteotomy ; Postoperative Period ; Swine ; Swine, Miniature

BACKGROUNDOpen pyeloplasty has been historically described as the gold standard for the surgical treatment of ureteropelvic junction obstruction (UPJO), even if new techniques have recently gained a prominent role in this field. Laparoscopic pyeloplasty (LP) is not widely prevelant because of the technically challenging nature and it represents the gold standard for UPJO only in expert hands. To overcome some difficulties and technical challenges encountered during pure laparoscopic pyeloplasty, we designed a set of new instruments and assessed them using porcine model.

METHODSAccording to the ideas from the surgeons, our medical engineer designed three new instruments, including the right angle laparoscopy scissors, the petal-shape ureter dilator and the guide tube. Four experienced laparoscopic experts were involved in a no survival porcine study to assess the help of these new instruments. Four experiments were conducted on live pigs that weighed 22 to 25 kg at the same time. After general anesthesia was administered, transperitoneal ureteroureterostomy was performed using standard laparoscopic instruments, including placing the double J stent anterograde. Then, the opposite lateral was done by the same surgeon plus these new devices for side-by-side comparative analysis. All experts were interviewed to assess these new instruments by the questionnaire based on the visual analog scale (VAS) from 1 (none) to 10 (very much).

RESULTSThe procedures were all technically successful. The right angle laparoscopy scissors and the guide tube were accepted by all participants and the Help Score were 6.75 and 4.25 respectively, at the same time the New Difficulty Score 1.25 and 1.75. However, the petal-shape ureter dilator got 1.5 Help Score and 6.5 New Difficulty Score. These surgeons made a negative comment and one of surgeons recommended the stone basket was more suitable.

CONCLUSIONThe right angle laparoscopy scissors and the guide tube may be helpful to minimize some difficulties in pure laparoscopic pyeloplasty.

Animals ; Kidney Pelvis ; surgery ; Laparoscopy ; instrumentation ; methods ; Stents ; Swine

Considering the problems such as reposition limited, easily detached and singly fired of the existing clip products, we developed an endoscopic multiple-clip applier which can apply 4 clips fired successively at a time. Th instrument also equipped with an independent grasper which can be used to clamp target tissues. In order to explor its feasibility and effectiveness of endoluminal closure of gastric perforation, 22 pig stomachs were making a 1 cm full-thickness incision from outside and closed by multiple-clip applier (n = 12) in vitro. Outcome was measured by bursting pressure and compared with negative control (n = 5) and hand suture (n = 5). We set a threshold pressure value (10 mm Hg) for a secure closure. Except 2 cases of invalid data, the mean bursting pressures of negative control, multiple-clip applier, hand suture were (1.5 ± 0.3) mm Hg, (46.0 ± 7.1) mm Hg, and (72.5 ± 7.7) mm Hg, respectively. The results showed that bursting pressure of multiple-clip applier was significantly higher than that of negative control (P < 0.05) and threshold value. Multiple-clip applier can be served as an effective and safe device to perform the endoluminal closure of gastric perforation.
Animals ; Endoscopy ; Equipment Design ; Stomach Diseases ; surgery ; Surgical Instruments ; Swine