Purpose: In histotripsy, a shock wave is transmitted, and the resulting inertial bubble cavitation that disrupts tissue is used for treatment. Therefore, it is necessary to detect when cavitation occurs and track the position of cavitation occurrence using a new passive cavitation (PC) imaging method. Methods: An integrated PC image, which is constructed by collecting the focused signals at all times, does not provide information on when cavitation occurs and has poor spatial resolution. To solve this problem, we constructed instantaneous PC images by applying delay and sum beamforming at instantaneous time instants. By calculating instantaneous PC images at all data acquisition times, the proposed method can detect cavitation when it occurs by using the property that when signals from the cavitation are focused, their amplitude becomes large, and it can obtain a high-resolution PC image by masking out side lobes in the vicinity of cavitation. Results: Ultrasound image simulation confirmed that the proposed method has higher resolution than conventional integrated PC imaging and showed that it can determine the position and time of cavitation occurrence as well as the signal strength. Conclusion Since the proposed novel PC imaging method can detect each cavitation separately when the incidence of cavitations is low, it can be used to monitor the treatment process of shock wave therapy and histotripsy, in which cavitation is an important mechanism of treatment.

Neuroendocrine tumor (NET) of the colon and rectum has been reported to have a low incidence and aggressive progression; it is frequently misdiagnosed and its treatment is not well documented. Four NET cases were collected at our hospital during the previous year of a colon cancer survey. Endoscopic mucosal biopsy of the colon was done for each case and all the cases proved to be adenocarcinomas. Curative surgery was conducted after the preoperative diagnostic and staging evaluation was completed. The locations of the primary lesions of the patients were all different; cecum, ascending colon, splenic flexure colon and sigmoid colon. The disease was advanced in all cases and the first postoperative diagnosis was poorly differentiated adenocarcinoma. Immunohistochemical tests followed and all the cases were positive for chromogranin A staining. A retrospective study was then conducted.
Adenocarcinoma ; Biopsy ; Cecum ; Chromogranin A ; Colon* ; Colon, Ascending ; Colon, Sigmoid ; Colon, Transverse ; Colonic Neoplasms ; Diagnosis ; Humans ; Incidence ; Neuroendocrine Tumors* ; Rectum ; Retrospective Studies

PURPOSE: To evaluate the nature and frequencies of the complications of scleral buckling surgery. METHODS: The medical records of 222 eyes of 218 patients who had undergone primary scleral buckling surgery using silicone exoplant from January 1993 to June 1999 by one surgeon and who had been followed up for more than 6 months after surgery were reviewed retrospectively. RESULTS: For intraoperative complications, scleral perforation occurred in 24 cases (9.9%) and subretinal hemorrhages in 17 cases (7.0%) out of 243 procedures. For postoperative complications, surgical failure of the primary surgery occurred in 49 eyes (22.1%), temporary increase of intraocular pressure in 13 eyes (6.7%), macular complications in 8 eyes (4.3%), choroidal detachment in 3 eyes (1.5%), strabismus in 2 patients (1.2%), conjunctival cyst in 2 eyes (1.0%) and extrusion of the buckling material in 1 eye (0.5%). Scleral encircling induced myopia of average 2.36 diopters in 13 eyes. The main causes of the primary failure were proliferative vitreoretinopathy in 21 eyes (42.9%) and inadequate buckling in 11 eyes (22.4%). CONCLUSIONS: The most common complication after scleral buckling surgery using silicone exoplant was scleral perforation intraoperatively and persistent or recurrent retinal detachment postoperatively. Temporary increase of intraocular pressure, refractive change, macular complications also occurred postoperatively.
Choroid ; Hemorrhage ; Humans ; Intraocular Pressure ; Intraoperative Complications ; Medical Records ; Myopia ; Postoperative Complications ; Retinal Detachment ; Retrospective Studies ; Scleral Buckling* ; Silicones ; Strabismus ; Vitreoretinopathy, Proliferative

No abstract available.

No abstract available.

When doctors evaluate the complaints of dizziness, they often perform a series of clinical tests to look for the evidence of a vestibular dysfunction. A useful procedure is to ask the patient to take deep breaths and observe the gaze behind Frenzel goggles. If hyperventilation-induced nystagmus(HIN) is detected, it is the evidence for an underlying vestibular imbalance. The authors evaluated nystagmus with electronystagmography after hyperventilation for 50 seconds. Brain imaging was performed to search the responsible lesion for dizziness. Brain MRI revealed a brain tumor suggesting vestibular schwannoma in the left cerebellopontine angle. After hyperventilation, dizziness and the right beating horizontal nystagmus with Alexander law could be detected. By precisely measuring the HIN, we determined that inputs arising from the horizontal semicircular canal were mainly responsible. The contralaterality of the direction of the horizontal component of the nystagmus was detected. We suggest that clinicians should routinely check the nystagmus after hyperventilation, when they evaluate patients complaining of dizziness.
Brain ; Brain Neoplasms ; Cerebellopontine Angle ; Dizziness ; Electronystagmography ; Eye Protective Devices ; Humans ; Hyperventilation* ; Jurisprudence ; Magnetic Resonance Imaging ; Neuroimaging ; Neuroma, Acoustic* ; Nystagmus, Pathologic ; Semicircular Canals

Iatrogenic vascular injury during lumbar disc surgery is a rare but serious complication. This paper reports a patient who sustained an injury to the iliac artery while undergoing intervertebral disc surgery at the lumbar region. He suffered from massive bleeding and shock. An urgent laparatomy was performed under cardiopulmonary bypass, and the vascular injuries were repaired successfully. This case shows that a rapid diagnosis and immediate intervention can result in a favorable outcome.
Cardiopulmonary Bypass ; Diskectomy ; Hemorrhage ; Humans ; Iliac Artery ; Intervertebral Disc ; Lumbosacral Region ; Rupture ; Shock ; Vascular System Injuries

PURPOSE: Chylous ascites is an accumulation of lymphatic fluid within the peritoneal cavity due to trauma or to an obstruction on the lymphatic system. Postoperative chylous ascites is a rare complication of abdominal surgery. It is frequently reported after retroperitoneal dissections and results in high morbidity and mortality. However, there have been few report of such a complication following a radical gastrectomy. Therefore, we review the clinical analysis and treatment of chylous ascites based on our experience. MATERIALS AND METHODS: From July 1992 to June 2001, we treated 13 cases of chylous ascites after operations for gastric cancer. We reviewed medical charts of those patients retrospectively. RESULTS: The incidence of chylous ascites after operations for gastric cancer was 0.83% (13/1552). The mean time from ingestion of a meal after the operation to the development of symptoms was 2 days (range: 1~6 days). Conservative treatment by fasting, total parenteral nutrition (TPN), and repeated paracentesis was successful in all patients. The mean time from diagnosis to complete resolution was 25 days (range: 2~105 days). CONCLUSION: Chylous ascites should be considered in any patient with a typical milky color of drainage who has recently undergone radical gastrectomy. Treatment with fasting, TPN, and repeated paracentesis usually is successful.
Chylous Ascites* ; Diagnosis ; Drainage ; Eating ; Fasting ; Gastrectomy ; Humans ; Incidence ; Lymphatic System ; Meals ; Mortality ; Paracentesis ; Parenteral Nutrition, Total ; Peritoneal Cavity ; Retrospective Studies ; Stomach Neoplasms*

PURPOSE: Metacarpal fractures are common hand injury that may require operative intervention to ensure adequate reduction and stabilization. Traditionally, titanium miniplate was used for rigid fixation of bone fractures. However, the use of permanent plate lends itself to multiple complications such as infection, exposure of the hardware, tendon adhesions, tendon rupture, prolonged pain, bony atrophy and osteoporosis (stress shielding), metal sensitization, and palpation under the skin. This study evaluated the usefulness and stability of biodegradable plates and screws for treatment of metacarpal bone fractures. METHODS: There was 17 patients who had surgery for metacarpal bone fracture from April 2007 to June 2010. All patients had open reduction and internal fixation. We used absorbable plates and screws (Inion CPS(R)) for internal fixation. Postoperative results were assessed with x-ray. Stability of plates and screws, healing process and its complications were observed by clinical and radiographic assessment. RESULTS: All patients were successfully reduced of bone fracture, and fixations with absorbable plates and screws were stable. The mean follow up period was 7.1 months. 2 patients complained postoperative pain, but they were relieved with analgesics. All patients experienced transient stiffness, but they were relieved with active assistive range of motion after removal of splint. No patients suffered complications which could be occurred by using metallic plate. CONCLUSION: There was no critical complications such as re-fracture or nonunion among patients. No patients suffered side effects related with metallic implants. Biodegradable implants can offer clinically stable and attractive alternative to metallic implants to stabilize metacarpal bone fractures in the hand.
Absorbable Implants ; Analgesics ; Atrophy ; Dietary Sucrose ; Follow-Up Studies ; Fracture Fixation ; Fractures, Bone ; Hand ; Hand Injuries ; Humans ; Metacarpal Bones ; Osteoporosis ; Pain, Postoperative ; Palpation ; Range of Motion, Articular ; Rupture ; Skin ; Splints ; Tendons ; Titanium

Changes in nitric oxide production in spinal cord or dorsal root ganglion have been known to contribute to allodynia after nerve injury. However, regulation of nNOS expression was also reported not to be responsible for the development and/or maintenance of neuropathic allodynia. The aim of this study was to elucidate role of nNOS expression in the sensory nervous system in neuropathic pain. Von Frey and acetone tests were performed in a model of peripheral neuropathy, ligation of 5th lumbar and 6th lumbar spinal nerves, in wild type and nNOS (-/-) mice. The effect of nNOS inhibitor was evaluated in neuropathic pain behavior in the mice. Mechanical allodynia was slightly reduced in nNOS (-/-) mice compared with wild type mice after peripheral neuropathy. nNOS inhibitor, L-NAME, reduced minimally mechanical allodynia, not cold allodynia, but gabapentin reduced remarkably neuropathic pain behavior (mechanical and cold allodynia) in both wild type and nNOS (-/-) mice. These results suggested that nNOS expression in the sensory nervous system may be partially associated with development and/or maintenance of mechanical allodynia in a mouse model of peripheral neuropathy.
Acetone ; Animals ; Ganglia, Spinal ; Hyperalgesia ; Ligation ; Mice ; Mice, Knockout* ; Nervous System ; Neuralgia* ; NG-Nitroarginine Methyl Ester ; Nitric Oxide ; Peripheral Nervous System Diseases ; Spinal Cord ; Spinal Nerves