An experimental sheep model used to develop an ablation procedure for chronic atrial fibrillation.

BACKGROUND: Atrial fibrillation is the most common form of serious arrhythmia in humans. The therapeutic options offered are medical, surgical, and interventional. The surgical approach is justified in cases of atrial fibrillation already subjected to cardiac surgery for an associated organic heart disease such as a valvular or ischemic disease. A minimally invasive surgical approach is needed to extend the possibility of surgical treatment to patients with lone atrial fibrillation and those who cannot be treated by interventional procedures. This study aimed to use sheep as an experimental model in developing a minimally invasive surgical procedure for chronic atrial fibrillation therapy in humans. METHODS: The investigation was conducted with 20 animals using a video-assisted thoracoscopic approach, in which a flexible microwave energy ablating probe was positioned on the epicardial surface encircling the pulmonary veins. RESULTS: In 10 of the 20 animals, it was possible to encircle the pulmonary veins using the thoracoscopic approach in less than 3 h without major complications. CONCLUSION: The epicardial ablation procedure using the thoracoscopic approach is feasible, safe, and reproducible.

Conservative approach to Hepatic Portal Venous Gas: A case report.

INTRODUCTION: Hepatic Portal Venous Gas (HPVG), a rare condition in which gas accumulates in the portal venous circulation, is often associated with a significant underlying pathology, such as Crohn's disease, ulcerative colitis, diverticulitis, pancreatitis, sepsis, intra-abdominal abscess, endoscopic procedures, mesenteric ischemia, abdominal trauma. PRESENTATION OF CASE: Here we report a case of HPVG in an 82-year-old patient who underwent a left colectomy for stenosing tumor of the descending colon. The patient was treated conservatively, and his symptoms resolved. Follow-up computed tomography (CT) scan showed complete resolution of HPVG. DISCUSSION: The mechanism underlying the passage of the gas from the intestine into the mesenteric, then portal, venous system is not fully understood. Historically, this condition has been related to acute intestinal ischemia, as a consequence of a bacterial translocation through a wall defect. CONCLUSION: This case underscores the role of conservative management, highlighting how the severity of the prognosis of HPVG should be related to the underlying pathology, and not influenced by the presence of HPVG itself.

Abdominal Wall Schwannoma.

Neurilemmomas-or schwannomas-are rare soft tissue tumours involving peripheral nerve sheaths, usually found in the head and neck regions. They can infrequently originate within the tissues of the abdominal wall. Here, we present a case of symptomatic schwannoma of the abdominal wall in a 62-year-old woman referred for abdominal pain in the right iliac fossa. On physical examination, a 5-7-cm oval-shaped area of consolidation with regular borders and elastic consistence was palpable. Ultrasound examination of the abdomen revealed a hypoechogenic mass measuring 80-33-42 mm; subsequently, a CT scan confirmed the presence of a well-circumscribed mass, with small calcifications inside. Radical excision of the lesion under general anaesthesia was performed, and the histological examination was consistent with the diagnosis of "ancient" schwannoma. The patient was discharged on the second postoperative day, and, at a clinical check 1 month postoperation, she reported no recurrence of abdominal pain and had an improved quality of life. Schwannomas have a good prognosis overall, with malignant degeneration being very rare. Local recurrence is plausible only if non-radical resection of the primitive tumour occurs. This is the second case ever reported, to our knowledge, of symptomatic schwannoma of the abdominal wall. We advocate surgical removal of the tumour when it presents as a cause of abdominal pain, ensuring that a radical excision is performed due to the possibility-though rare-of malignant transformation or recurrence. This offers the possibility of total regression of symptoms through surgical therapy.

Nonfunctional paraganglioma of the head of the pancreas: A rare case report.

BACKGROUND: Paragangliomas are rare neoplasms that originate from the neural crest. They are malignant in approximately 10% of cases, with a 50% survival rate at 5 years from diagnosis. In most cases, manifestations of malignancy (such as metastasis) are lacking, and paragangliomas are considered benign lesions. Pancreatic paragangliomas are extremely rare, with only 31 cases described in the scientific literature to date. CASE SUMMARY: Here we describe a case of a 55-year-old Caucasian male patient referred to our institution in September 2013 for lumbar pain lasting five months. The ultrasound and the CT scan revealed a 2.5cm solid nodule located in the uncinate process of the pancreas. On the basis of this evidence, the preoperative diagnosis was a pancreatic neuroendocrine tumor (NET), which was further confirmed by a subsequent In-Pentetreotide Scan examination. A pylorus-preserving duodenocephalopancreasectomy was performed. Pancreatic paraganglioma was the final pathological diagnosis. Rare localizations of paraganglioma are often discovered casually, during imaging examinations for other clinical reasons, as happened in the case of our patient. It appears evident that the preoperative diagnosis of pancreatic paragangliomas is extremely challenging. Surgery represents the cornerstone of the clinical management of these neoplasms, primarily for the need of a definitive diagnosis, which is difficult to assess preoperatively in most cases. CONCLUSIONS: Our strategy is the same as that adopted for the management of pancreatic NETs; the dimensional limit for a conservative resection is 2cm, while major resections (Whipple's approach or distal pancreatectomy) should be employed in larger tumors, which are generally associated with a worse prognosis.

Photodynamic therapy of spontaneous animal tumors using the active component of hematoporphyrin derivative (DHE) as photosensitizing drug: clinical results.

Photodynamic therapy was performed on 25 primary spontaneous tumors in dogs and cats. The animals were injected with 2.5 mg/kg body wt. of tumor localizing fraction of hematoporphyrin derivative and treated 48 h later with laser light at 631 nm. In 5 cases the treatment was performed on the tumor bed after surgical excision of the tumor mass. An evaluation of clinical results is presented and discussed. Complete remission was obtained in 19 cases and partial remission in 6 cases.

Hematoporphyrin derivative photochemotherapy of spontaneous animal tumors: clinical results with optimized drug dose.

Hematoporphyrin derivative (HpD) photochemotherapy was performed on 13 primary spontaneous tumors in dog and cat. The animals received an optimized drug dose of 5 mg/kg body wt i.v. 48 h before the first treatment with laser light at 631 nm. An evaluation of the clinical results is presented and discussed. Complete disappearance of the primary tumors was obtained in all cases with one or more light irradiations. Five cases presented recurrences that were cured with a further treatment. In 4 cases treated after surgical exeresis of the primary tumors, this therapy resulted in complete cure.

Anatomic and surgical approach to the ethmoidal nerve and parasympathetic innervation of the nasal and cerebral circulation in sheep.

OBJECTIVE: To describe an anatomic and surgical approach to the efferent parasympathetic branches of the pterygopalatine ganglia in sheep, with particular reference to the ethmoidal nerve and innervation of nasal and cerebral blood vessels. ANIMALS: 12 adult sheep used for monolateral (n = 7) or bilateral (n = 5) ethmoidal neurectomy; 2 sheep used for angiography (1 live sheep for digital subtraction angiography, 1 embalmed cadaver for injection studies); and 5 embalmed cadavers, 4 frozen specimens, and 2 dry skulls used for dissection, x-rays, and computed tomographic (CT) or magnetic resonance (MR) scans. PROCEDURE: Transverse (coronal) MR scans, transverse, sagittal, and dorsal CT scans, radiography, angiography, photographic images, and dissections of embalmed material were used to study the topographic anatomy of the temporal and pterygopalatine fossae of the head. RESULTS: Images were stored, then compared with photographs of frozen sections from the same or a similar specimen to plan a surgical approach to the ethmoidal nerve. Mono- and bilateral experimental ethmoidal neurectomies were performed, allowing characterization of a safe and reliable method. The series of pterygopalatine ganglia typical of this species was localized, dissected, and analyzed for topographic relations. CONCLUSIONS: From the results, a new approach to the efferent branches of the pterygopalatine ganglia (ethmoidal nerve) for experimental parasympathectomy of the cerebral and nasal circle is proposed. This experimental approach could be used for studies involving thermoregulation of the face, and in experimental control of blood flow in the nasal cavity and rostral part of the brain.

Comparison of results of scanning electron microscopy and magnetic resonance imaging before and after administration of a radiographic contrast agent in the tendon of the deep digital flexor muscle obtained from horse cadavers.

OBJECTIVE: To analyze the tendon of the deep digital flexor (TDDF) muscle of the forelimb in horses by use of a contrast radiographic agent (gadopentate dimeglumine [Gd-DTPA/Dimeg]) and magnetic resonance imaging (MRI) and to determine the concentration of water protons in the tendons by use of MRI. SAMPLE POPULATION: 8 TDDF harvested from the forelimbs of 6 horse cadavers. PROCEDURE: Examinations were performed on the same portion of each tendon. Tendons were examined by use of two techniques: MRI before and after treatment with Gd-DTPA/Dimeg as well as scanning electron microscopy. RESULTS: Tendons did not have detectable signal intensity on MRI before treatment with Gd-DTPA/Dimeg; however, intravascular injection of Gd-DTPA/Dimeg allowed evaluation of the internal structure of the tendons Scanning electron microscopy images correlated well with images obtained by use of MRI before and after administration of Gd-DTPA/Dimeg. Localized spectra revealed the concentration of water protons in the TDDF. CONCLUSIONS AND CLINICAL RELEVANCE: The techniques used in this study provided information about internal organization of the TDDF in horses. Analysis of results revealed that the best technique involved vascular injection of contrast medium. Results of MRI correlated well with results for scanning electron microscopy. After administration of Gd-DTPA/Dimeg, MRI provided additional information about tendon morphologic characteristics. This technique may be of value for examination of tendons in lame horses.

Tubular e-PTFE implants in glottal and neoglottal insufficiency: tolerance and stability in an animal model.

The aim of our research is to develop a laryngeal tissue augmentation technique that will be useful in treating glottal and neoglottal insufficiency. In a previous study the feasibility of insertion of tubular expanded poly-tetrafluoroethylene (e-PTFE) tissue implants into the larynx of a porcine model was demonstrated. In this paper we report the clinical, endoscopic, computed tomography (CT) and magnetic resonance image (MRI) and histopathological follow-up findings. These results demonstrate host tolerance of the implant over the period of study (six months) with little tissue reactivity to tubular e-PTFE implants in the porcine model. The tubular shape of the implant enhances stabilization by the rapid and complete host tissue penetration of the implant's interstices, making tubular e-PTFE a potentially useful soft tissue augmentation material for laryngeal incompetence.

[Laparoscopic nephrectomy]. / Nefrectomia laparoscopica.

Laparoscopic nephrectomy is a new procedure in which the entire kidney is removed introducing it in an Endopouch and, after morcellation pulled out through a 12 mm port. After an initial experimental experience, in our Institute we have performed one laparoscopic nephrectomy for left pyelonephritic kidney and ureteral reflux. The operation required the positioning of 5 trocars and 4 hours for its execution. The discharge of the patient was possible four days after.

[Laparoscopic cystectomy: an experimental model of urinary diversion]. / Cistectomia laparoscopica: un modello sperimentale di derviazione urinaria.

During our experimental trial we achieved laparoscopic cistectomies with urinary diversion to prove our manual capability with the reconstructive surgery. We executed, on male pigs, 10 cistectomies with urinary diversion using laparoscopic technique. We performed 5 ureterocutaneostomies on 5 pigs and, in the other ones, 5 ureterosigmoidostomies. During UCS the pigs laid in lateral position, and during USS in supine position. The average time of the operation is going to reduce in consideration of the overcoming of the initial techno-instrumental difficulties and is 60 minutes for cistectomy, 30 minutes for ureterocutaneostomy and 120 minutes for ureterosigmoidostomy.

[Idiopathic "benign" pericarditis in dogs. Clinical and therapeutic reflections]. / Die idiopathische "gutartige" Perikarditis beim Hund. Klinische und therapeutische Uberlegungen.

The authors present a case of benign idiopathic pericarditis in dog, describing a clinical case. The most important reasons for pericardial effusion are analyzed. Clinical signs of cardiac tamponade and aspects of electrocardiographic examination are demonstrated. Inconsistent long-term results achieved using corticosteroid therapy induced the authors to perform partial pericardiectomy (pericardial fenestration). The surgical approach was curative and, one year later, the dog doesn't show any signs of clinical disease.

Use of magnetic resonance imaging for diagnosis of a spinal tumor in a cat.

Magnetic resonance imaging was used to identify a spinal mass at the level of the 6th-7th cervical vertebral body in a cat. The MRI images were most consistent with the presence of an intradural, extramedullary meningioma that was confirmed by subsequent histological examination.

In vivo study of polyurethane-coated Gianturco-Rosch biliary Z-stents.

PURPOSE: Prototypes of Gianturco-Rosch Z-stents coated with polycarbonate urethane (PCU) were placed in the biliary tree of pigs, in order to test their biomechanical behavior, stability, and biocompatibility. METHODS: The stents were surgically implanted in the common bile duct of three pairs of pigs, which were killed after 1, 3, and 6 months respectively. Explanted livers from pigs of the same race, age, and size were used to provide comparative data. The bile ducts were radiologically and histopathologically examined; the stents were processed and examined by scanning electron microscopy. RESULTS: No complications occurred and the animals showed a normal weight gain. The main bile duct appeared radiologically and macroscopically dilated, but the stents proved to be in place. Histologically, the bile duct epithelium was destroyed, but neither hyperplastic nor inflammatory fibrotic reactions of the wall were evident. Both the metallic structure and the polymeric coating of the stents were intact. A layer of organic material with a maximum thickness of approximately 3 micron was evident on the inner surface of the stents. CONCLUSION: The present in vivo study demonstrates the biocompatibility, efficacy, and stability of PCU-coated Gianturco-Rosch stents in the biliary environment.