Jae Cheol Hwang

Covered Retrievable Tracheobronchial Hinged Stent: An Experimental Study in Dogs

PURPOSE To evaluate the safety and technical feasibility of the use of a covered retrievable tracheobronchial hinged stent and investigate the histopathologic airway changes after placement and removal of the stent in dogs. MATERIALS AND METHODS The experimental stent was composed of tracheal and bronchial stents that were connected together at their ends. Each stent was woven from a single thread of 0.2-mm-diameter nitinol wire filament in a tubular configuration and covered with polyurethane solution by a dipping method. Drawstrings were attached at the upper end of the tracheal stent for stent removal. Under fluoroscopic guidance, 20 stents were placed at the lower trachea and left main bronchus in 20 dogs and were electively removed 4 weeks (n = 10) or 8 weeks (n = 10) after placement. Ten dogs were killed just after stent removal and the remaining 10 were killed 2 weeks after stent removal. RESULT Stents were successfully placed in all dogs. Pneumonia was observed in three dogs. Stent migration occurred in seven dogs (35%). Except for two cases of stent expectoration, 18 stents were easily removed within a few minutes. There was considerable granulation tissue proliferation and inflammatory reaction in the airways of the dogs that were killed just after stent removal. The pathologic changes of the airways returned to almost-normal conditions 2 weeks after stent removal. CONCLUSION Placement and removal of a covered retrievable tracheobronchial hinged stent seems to be feasible, and histopathologic changes of the airway related to the stents returned to normal 2 weeks after stent removal.

Classification of persistent primitive trigeminal artery (PPTA): a reconsideration based on MRA.

Background Persistent primitive trigeminal artery (PPTA) is the most common permanent carotid-basilar anastomosis. Magnetic resonance angiography (MRA) has become the primary non-invasive imaging technique for evaluation of cerebral vascular anatomy and can provide detailed 3D imaging of intracranial vessels. Purpose To evaluate the usefulness of MRA for the detection of PPTA and to re-classify its variations based on the embryologic types of PcomA and its relationship with the basilar artery and its branches. Material and Methods Of the total 7329 patients who underwent MRA at our institution from March 2008 through November 2010, we retrospectively analyzed the MRAs of 24 patients with a PPTA. Special attention was given to defining the relationship of the PPTA and the basilar artery with PcomA and to determine the site of origin, size, and course of the PPTA. The PPTA classification included five types based on their anatomic relationship to the neighboring arteries. Clinical features and associated vascular anomalies are also described. Results Twenty-four (17 women and seven men, 34 ∼ 81 years of age, mean age 59.67 years) of the 7329 patients had a PPTA (0.33 %). Eleven cases (45.8%) were classified as type 1, three (12.5%) as type 2, five (20.8%) as type 3, one (4.2%) as type 4, and four (16.7%) as type 5b. Fifteen PPTAs (62.5%) were located on the left side and nine were located (37.5%) on the right side. The basilar artery proximal to the insertion of the PPTA showed severe to moderate hypoplasia in 13 cases (54%). Nine intracranial artery aneurysms were detected in seven (29%) of the 24 study patients. Conclusion This study revealed five types of PPTA and necessitates an adjustment of the previous classification of PPTA on the basis of our MRA examinations. A PPTA should be considered by both the clinician and the radiologist who interpret MR angiography.

A New Model of Tracheal Stenosis in Dogs Using Combined Bronchoscopic Electrocautery and Ethanol Injection

PURPOSE To establish a new animal model of tracheal stenosis in dogs that involves combined bronchoscopic electrocautery and ethanol injection. MATERIALS AND METHODS Ten mongrel dogs were included in the study. With flexible bronchoscopic and fluoroscopic guidance, a combination of electrocautery (30 W) and ethanol injection (total volume 2 mL) was circumferentially applied to the trachea at the third thoracic vertebra level. Dogs were euthanized 4 weeks later and the stenosis diameter and histologic findings were evaluated. RESULTS All procedures were successful. Eight of the 10 dogs survived to 4 weeks, whereas two died from respiratory failure before the planned endpoint. For the eight full-term dogs, the mean percentage diameter stenosis (+/-SD) was 70.8%+/-9.3%, with a range of 56%-81%. Microscopic analysis showed that the maximum tracheal wall thickness was 2.48 mm+/-0.77. The degree of inflammatory cell infiltration varied, but cartilage destruction and mucosal ulceration were evident in all cases. CONCLUSIONS A new tracheal stenosis model was developed in dogs with use of combined bronchoscopic electrocautery and ethanol injection. This animal model is a technically simple, reliable, and tracheotomy-free model for the creation of tracheal stenosis.

Percutaneous placement of self-expandable metallic biliary stents in malignant extrahepatic strictures: indications of transpapillary and suprapapillary methods.

Objective To compare the efficacy of suprapapillary and transpapillary methods of transhepatic biliary metallic stent placement in malignant biliary strictures and to specify the indications of each method applied. Materials and Methods Stents were placed in 59 patients. Strictures were categorized as type A (within 3 cm of the ampulla, n = 27), type B (over 3 cm from ampulla, n = 7), type C (within 3 cm of the bending portion, n = 9), or type D (over 3 cm above the bending portion, n=16). The stenting method was suprapapillary in 34 cases and transpapillary in 25. The rates of initial and long-term patency and of early recurrence were compared. Results Initial patency rates for the suprapapillary and transpapillary methods were 1/7 (14.3%) and 20/20 (100%) respectively for type A (p < 0.0001), 4/5 (80.0%) and 2/2 for type B, 3/7 (42.9%) and 2/2 for type C, and 15/16 (93.8%) and 0/0 for type D. Early recurrence rates were 7/30 (23.3%) using the suprapapillary method and 4/29 (13.8%) using the transpapillary method (p = 0.51). The long-term patency rate did not differ significantly according to either type (p = 0.37) or method (p = 0.62). Conclusion For good initial patency, the transpapillary method is recommended for strictures of the distal extrahepatic duct near the ampulla and just above the bending portion. Long-term patency is not influenced by the stenting method employed.

Colonic wall thickening in cirrhotic patients: CT features and its clinical significance

AbstractBackground: To evaluate the computed tomographic (CT) features of colonic wall thickening in cirrhotic patients and to determine their prognostic value. Methods: We retrospectively reviewed 28 cirrhotic patients with colonic wall thickening (≥10 mm) on CT. Twenty-six of the 28 patients had hepatocellular carcinoma. The severity of hepatic dysfunction was determined by using the Child–Pugh classification. We analyzed the patterns of bowel wall thickening and degree of portal hypertension on CT and the survival periods after initial CT detection of colonic wall thickening. Results: The involved segment of the colon was diffusely thickened with either scalloped or nodular circumferential configuration. In all patients, the thickened colonic wall enhanced poorly. Although the ascending colon was involved in all patients, the transverse (n= 14) or descending (n= 5) colon was also simultaneously involved. Most patients exhibited an advanced stage of portal hypertension on CT. The median survival period of 25 patients who expired was 34 days, and 21 patients (84%) expired within 3 months. Conclusions: Colonic wall thickening on CT can be used as one of the indicators of poor prognosis in cirrhotic patients. Advanced liver cirrhosis with significantly severe dysfunction is the likely cause of mortality. Therefore, a less aggressive therapeutic approach is recommended if hepatocellular carcinoma is coexistent in these patients.

Pleural and pulmonary staining at inferior phrenic arteriography mimicking a tumor staining of hepatocellular carcinoma

Purpose: To describe the findings of pleural and pulmonary staining of the inferior phrenic artery, which can be confused with tumor staining during transarterial chemoembolization (TAGE) of hepatoma.Methods: Fifteen patients who showed pleural and pulmonary staining without relationship to hepatic masses at inferior phrenic arteriography were enrolled. The staining was noted at initial TAGE (n=8), at successive TAGE (n=5), and after hepatic surgery (n=2). The angiographic pattern, the presence of pleural change on computed tomography (CT), and clinical history were evaluated.Results: Draining pulmonary veins were seen in all cases. The lower margin of the staining corresponded to the lower margin of the pleura in 10 patients. CT showed pleural and/or pulmonary abnormalities in all cases. After embolization of the inferior phrenic artery, the accumulation of iodized oil in the lung was noted.Conclusion: Understanding the CT and angiographic findings of pleural and pulmonary staining during TAGE may help differentiate benign staining from tumor staining.

Hemothorax caused by spontaneous rupture of a metastatic mediastinal lymph node in hepatocellular carcinoma: a case report.

To the Editor, The frequency of massive hemoperitoneum caused by spontaneous rupture of hepatocellular carcinoma (HCC) has been reported to be 10% to 18% because of the extensive vascular structure and relatively small amount of fibrous tissue in these tumors [1]. Hemothorax caused by rupture of a lung or pleural metastasis of HCC occurs less frequently. Although one case of cardiac tamponade caused by spontaneous rupture of a metastatic mediastinal lymph node (MLN) has been described [2], to our knowledge, no case of hemothorax due to spontaneous rupture of a metastatic MLN of HCC has been reported in the Korean- or English-language literature. We describe here a case of massive hemothorax due to spontaneous rupture of a metastatic MLN in HCC. A 60-year-old male Korean farmer was brought to the Department of Emergency, Ulsan University Hospital with dyspnea and left pleuritic chest pain within 6 hours after symptom onset. Six years earlier, he was diagnosed with chronic hepatitis B-related cirrhosis and 4 years earlier he had been diagnosed with HCC (Fig. 1A) and underwent a right hepatic lobectomy. Multiple metastatic pulmonary nodules were detected 3 months after the surgery and the patient received six cycles of a cisplatin-based chemotherapy regimen over 6 months. Contrast-enhanced computed tomography (CT) scanning showed complete disappearance of the multiple metastatic lung nodules after chemotherapy. At 8 months after finishing the chemotherapy, however, he was readmitted to our hospital due to a single metastatic nodule in the left lower lobe of the lung and underwent metastasectomy with video-assisted thoracoscopic surgery (VATS). Pathological examination of the lung nodule removed showed results consistent with metastatic HCC. Figure 1 Chest computed tomography scans showing (A) a 10-cm sized intrahepatic peripheral capsular enhanced mass, (B) a single enlarged lymph node (white arrow) in the left inferior pulmonary ligament, and (C) a 73 × 84-mm ruptured low-attenuated central ... At 1 year before admission, CT images of the chest showed a single enlarged lymph node (LN) in the left inferior pulmonary ligament, regarded as a metastatic MLN of HCC (Fig. 1B). Two weeks before this admission, follow-up CT images showed enlargement of the metastatic MLN, and the patient was scheduled for additional chemotherapy. On the day of admission, the patient experienced an abrupt onset of dyspnea and left pleuritic chest pain. Physical examination on admission revealed an acutely ill-looking man with body temperature of 36.5℃, pulse rate of 130 beats per minute, blood pressure of 100/70 mmHg, and a respiration rate of 32 breaths per minute. Laboratory test results included hemoglobin 12.3 g/dL, hematocrit 33.4%, white blood cell count 4.37 × 103/µL, platelet count 9.9 × 104/µL, aspartate aminotransferase 47 IU/L, alanine aminotransferase 60 IU/L, total bilirubin 2.0 mg/dL, albumin 3.2 mg/dL, and α-fetoprotein 819.2 ng/mL. Chest X-rays showed a massive left-sided pleural effusion, with the trachea deviated to the right side. Massive hemothorax was diagnosed by thoracentesis. CT images of the chest revealed a 73 × 84 mm-sized ruptured low-attenuated central necrotic mass with massive left side hemothorax (Fig. 1C). A chest tube was inserted and approximately 1,200 mL of bloody fluid was drained. Arteriography of the bronchial arteries revealed a massive ruptured LN in the left inferior pulmonary ligament, to which blood was supplied by an accessory bronchial artery originating 10 cm beneath the left bronchial artery. These findings indicated that the massive hemothorax was caused by a spontaneous rupture of a metastatic MLN of HCC into the intrapleural space. Transcatheter arterial embolization (TAE) of the left bronchial artery was performed successfully, injecting 13 mL of lipiodol ultraf luide (Guerbet, Aulnay-sous-Bois, France) and 30 mg of adriamycin (doxorubicin hydrochloride) with polyvinyl alcohol particles (contour emboli, Interventional Therapeutics Corp., Fremont, CA, USA) (Fig. 1D). No complication was observed and the pleural effusion gradually disappeared thereafter. The patients dyspnea improved, as did his physical condition. Following removal of the chest tube, he was discharged after 15 days in the hospital and was followed monthly as an outpatient at the department of oncology for 3 months. Serial chest X-rays revealed a decrease in the size of the MLN with lipiodol embolization. Four months later, however, the patient died at home. Due to its vascular structure and relatively small amount of fibrous tissue, spontaneous rupture of HCC is not uncommon [1]. Rupture of HCC is considered a medical emergency and is associated with high mortality. HCC frequently metastasizes, most often to the lungs, LNs, bones, and adrenal glands. Moreover, HCC metastases, like the primary tumors, may rupture spontaneously. Sohara et al. [3] reviewed 10 cases with HCC complicated by hemothorax, including four case reports in Japanese, describing patients with metastasis to the chest wall and rib, lung, pleura, diaphragm, and MLN [4]. Those reports included the first case of hemothorax from spontaneous rupture of a mediastinal metastasis [4]. Common clinical presentations are chest pain and dyspnea initially [3]. Other signs are palpitations and hypotension, consistent with hypovolemic shock. Reported rare signs included massive hemoptysis and respiratory failure. Our patient also developed hemothorax with sudden-onset chest pain, dyspnea, and tachycardia. Ruptured HCC can be treated surgically or by TAE, with the latter now used widely for HCC ruptured into the peritoneal cavity. Masumoto et al. [5] first reported hemothorax due to HCC rupture successfully controlled by TAE and our case was also successfully controlled using TAE. On the other hand, surgically treated and untreated failures have been reported and drainage-only cases do allow complete control [3]. Our patient had been diagnosed with HCC 4 years earlier and had undergone various treatments, including right hepatic lobectomy, six cycles of chemotherapy for multiple lung metastases, VATS metastasectomy for a single metastasis in the lung, and TAE for rupture of metastatic MLN causing massive hemothorax. TAE was effective, in that bleeding was successfully controlled and pleural effusion did not recur. Our findings suggest that patients with HCC should be closely monitored and suitably managed to improve survival. In conclusion, this is the first report of hemothorax secondary to spontaneous rupture of metastatic MLN of HCC in the Korean- or English-language literature. The hemothorax was successfully treated with TAE. The various manifestations observed in patients with HCC suggest the need for careful monitoring and suitable management.

Delayed, life-threatening hemorrhage after self-expandable metallic biliary stent placement: clinical manifestations and endovascular treatment

Background Life-threatening, delayed hemorrhage after self-expandable metallic stent (SEMS) insertion for malignant biliary obstruction is very rare. Clinical manifestations, radiologic characteristics, treatment, and prognosis of this complication are not well-known. Purpose To present the clinical manifestations, radiologic findings, and endovascular treatment of life-threatening, delayed hemorrhage secondary to SEMS placement. Material and Methods A total of six patients (five men and one woman; mean age, 65.5 years) with life-threatening, delayed arterial bleeding after SEMS placement for malignant bile duct obstruction were recruited between 2000 and 2011 from three different hospitals in Korea. The original SEMS placement in all patients utilized either percutaneous (n = 3) or endoscopic approaches (n = 3). We retrospectively reviewed the clinical presentations, computed tomography (CT) and angiographic findings, endovascular treatments, and prognoses of these patients. Results All patients presented with life-threatening gastrointestinal bleeding such as melena (n = 4), hematochezia (n = 1), and hematemesis (n = 1). Mean time period between biliary metallic stent insertion and presentation with bleeding was 75 days (range, 15–152 days). All stents were encased by primary or metastatic cancer along with nearby arteries on CT images. Digital subtraction angiogram (DSA) revealed pseudoaneurysm close to the stent (n = 2), in-stent pseudoaneurysm (n = 2), arteriobiliary fistula (n = 1), or pseudoaneurysm with arteriobiliary fistula (n = 1). The origins of hemorrhage were the gastroduodenal artery (n = 3), the aberrant right posterior hepatic artery from the gastroduodenal artery (n = 2), and the right hepatic artery (n = 1). Hemorrhages were successfully controlled after intra-arterial coil embolization in five patients followed by placement of a stent graft and direct puncture N-butyl-2-cyanoacrylate (NBCA) embolization in one patient. Conclusion Life-threatening, delayed hemorrhage within a metallic biliary stent may occur if a stent is placed across the bulky bile duct tumor or tumor encases the stent. Bleeding can be successfully treated with endovascular treatment. However, the overall prognosis was poor.

The Hemoptysis and the Subclavian Artery Pseudoaneurysm due to a Fishbone Injury: A Case Report.

Abstract Ingestion of a foreign body is a common cause of esophageal injury, but hemoptysis is a rare manifestation of the esophageal penetration by a swallowed foreign body. The swallowing of a fishbone is hard to diagnose and the definite diagnosis is usually made during surgery. We describe the case of a 50-year-old man with direct injury to the lung parenchyma, the azygos vein, and the subclavian artery pseudoaneurysm due to a fishbone penetration from the upper esophagus into the lung. To our knowledge, this is the first case report that we know of in which a swallowed foreign body that penetrated from the upper esophagus into the lung caused vascular injuries and lung damage and it was solved by minimally invasive surgery and an endovascular stent. We successfully diagnosed and treated a case with the migration of the fishbone from the upper esophagus into the lung. A contrast-enhanced computed tomography (CT) scan is recommended to clarify the fact of vascular injury before surgery. Thoracoscopic operation (VATS) combined with endovascular treatment could be a safer and a more feasible treatment option in this rare condition.

Primary Neuroendocrine Carcinoma of the Breast Involving the Nipple- Areolar Complex

Primary neuroendocrine (NE) carcinomas of the breast are tumors that have morphologic features similar to those of NE tumors of both the gastrointestinal tract and the lung. They express NE markers in more than 50% of the cell population. 1 Although NE carcinomas can develop in many sites of the body, primary NE carcinomas of the breast are very rare, and to our knowledge, no case described in the radiologic literature has involved the nipple-areolar complex. We present our experience with a primary NE carcinoma of the breast involving the nipple-areolar complex and also describe the radiologic and histologic findings.