Acute pancreatitis after percutaneous insertion of metallic biliary stents in patients with unresectable pancreatic cancer.

AIM: To investigate the incidence and clinical characteristics of acute pancreatitis following percutaneous insertion of metallic biliary stents in patients with unresectable pancreatic cancer. The clinical efficacy of metallic stent insertion was also evaluated. MATERIALS AND METHODS: Data from 143 patients (75 men, 68 women; mean age, 65.8 years; range, 35-88 years) with unresectable pancreatic cancer who underwent percutaneous metallic biliary stent insertion between March 2007 and December 2017 were evaluated retrospectively. The incidence and clinical characteristics of acute pancreatitis were analysed. Stent patency and patient survival rates were calculated by Kaplan-Meier analysis. RESULTS: Technical success was achieved in all patients. Among 31 patients with serum amylase levels above normal values (30-110 U/l), only nine had symptoms of acute pancreatitis (incidence, 6.4%). No statistically significant risk factors were identified. Pancreatitis was successfully managed with conservative treatment at a mean of 2.9 days (range, 1-4 days). The median stent patency and patient survival times were 117 days (95% confidence interval [CI], 87-148 days) and 150 days (95% CI, 125-174.9 days), respectively. CONCLUSIONS: Acute pancreatitis was a relatively rare complication after percutaneous insertion of metallic biliary stents in patients with unresectable pancreatic cancer, and no significant risk factors were identified. Therefore, insertion of metallic biliary stents was seen to be a feasible and effective treatment approach in this patient group.

Interventional treatment of arterial injury during blind central venous catheterisation in the upper thorax: experience from two centres.

AIM: To evaluate the safety and clinical efficacy of interventional treatment for arterial injury during blind, central venous catheterisation in the upper thorax at two tertiary medical centres. MATERIALS AND METHODS: Eighteen consecutive patients (37-81 years; M:F=8:10) who underwent interventional treatment for the arterial injuries that occurred during central venous catheterisation without any imaging guidance between November 2007 and December 2018 were included. Clinical data, angiographic findings, detailed interventional procedures, and technical and clinical outcomes were analysed retrospectively. RESULTS: Arterial injury sites were the subclavian artery/branches (n=12), axillary artery/branches (n=2), and common carotid artery (n=4). The target vein was not correlated with the corresponding artery/branches in eight patients (44.4%); internal jugular vein to subclavian artery branches. Angiographic findings were pseudoaneurysm (66.7%, 12/18), contrast medium extravasation (22.2%, 4/18), or both (11.1%, n=2). A stent graft was inserted for the main trunk injuries in nine patients, with (n=2) or without (n=7) prior arterial branch embolisation to prevent potential endoleak, while embolisation for the arterial branch injuries was performed in nine patients. Direct percutaneous access with thrombin injection to the pseudoaneurysm or residual arteriovenous fistula was utilised in two. The technical and clinical success rate was 94.4% (17/18) each. There were no procedure-related complications. In one patient without immediate clinical success, there was a persistent pseudoaneurysm after stent graft placement, which was treated with in-stent balloon dilation. CONCLUSION: Interventional treatment serves as a safe and effective treatment modality for inadvertent arterial injury related to blind, central venous access catheterisation in the upper thorax.

Interventional treatment of bleeding complications due to percutaneous cannulation for peripheral extracorporeal membrane oxygenation.

PURPOSE: This study aimed to evaluate the safety and effectiveness of interventional techniques as a treatment for bleeding complications secondary to percutaneous cannulation for peripheral extracorporeal membrane oxygenation (PECMO). MATERIALS AND METHODS: Out of 1264 patients who underwent PECMO at our hospital between January 2009 and September 2018, we reviewed the clinical characteristics and outcomes of eight patients (4 men, 4 women; mean age, 54.9 years [range, 31-77 years]) who underwent percutaneous interventional treatment for bleeding complications secondary to percutaneous cannulation for PECMO. RESULTS: Both hemodynamic instability and coagulopathy were present in 7 patients who had direct injury during PECMO insertion and absent in one patient with pseudoaneurysm at the PECMO removal site. Percutaneous ultrasound-guided thrombin injection was performed in three patients with pseudoaneurysm of the common or superficial femoral artery, and adjunctive embolization was combined with microcoils or n-butyl 2-cyanoacrylate in two of them. Stent graft was inserted in four patients with contrast extravasation (n=3) from external iliac artery (n=1) or common femoral or iliac veins (n=2) ruptures or the fistula between the superficial femoral artery and vein (n=1). N-butyl 2-cyanoacrylate and coil embolization was performed for pseudoaneurysm from the internal pudendal artery branch in the remaining one patient. Technical success was achieved in all eight patients. There were no procedure-related complications. There was no rebleeding during the follow-up. CONCLUSION: Interventional treatment is a safe, technically feasible and therapeutically effective modality for treating bleeding complications secondary to a percutaneous cannulation for PECMO.

Bleeding after dilatation and curettage: the efficacy of transcatheter uterine artery embolisation.

AIM: To evaluate safety and clinical outcomes of uterine artery embolisation (UAE) for bleeding after dilatation and curettage (D&C) performed for abortion or termination. MATERIALS AND METHODS: The outcomes were analysed in 11 patients who underwent UAE for bleeding after D&C for missed abortions (n=8), caesarean scar pregnancies (n=2), or planned termination (n=1) between October 2001 and December 2013. Angiograms and medical records were retrospectively reviewed in order to obtain the patients' baseline characteristics, technical/clinical success rate, complications, and follow-up data regarding menstruation. RESULTS: Technical success, defined as successful catheterisation of both uterine arteries with embolisation to haemostasis, was 100%, whereas clinical success, defined as cessation of bleeding after the initial session of UAE and without the need for additional UAE or surgery for the purpose of haemostasis, was 81.8% (nine of 11). In the two patients with clinical failure due to recurrent vaginal bleeding after UAE, one patient underwent repeat UAE and showed a successful outcome, whilst the other patient required hysterectomy with pathological results of placenta increta. Two other patients underwent hysterectomy for placenta percreta or hydatidiform mole-mimicking remnant placenta. None of the patients included in the present series had procedure-related complications. Menstruation resumed in all eight patients with an intact uterus during the mean follow-up period. CONCLUSION: UAE may be a safe and effective treatment for bleeding after D&C, especially for women who wish to preserve their fertility; however, hysterectomy may be indicated for patients with a placental abnormality.

Transarterial embolisation of renal arteriovenous malformation: safety and efficacy in 24 patients with follow-up.

AIM: To evaluate the efficacy and safety of renal artery embolisation (RAE) for renal arteriovenous malformation (AVM) as well as its outcomes. MATERIALS AND METHODS: The technical and clinical success rates, radiological and laboratory findings, and complications of RAE for 31 renal AVMs in 24 patients (M:F=9:15, mean age 46 years) at two separate medical institutions were retrospectively evaluated. Technical success was defined as complete occlusion of feeding arteries with no residual nidus seen on post-treatment angiography. Clinical failure was defined as recurrence of haematuria, presence of AVM on follow-up ultrasound or computed tomography, repeated RAE or surgery for the control of haematuria. Overall clinical success was defined as resolution haematuria or disappearance of AVM on follow-up imaging after single or multiple sessions of RAE. RESULTS: Types of renal AVM were AVM, arterio-venous fistula (AVF) with intranidal aneurysm, and acquired AVF in 19, 1, and 4 patients, respectively. 18 patients (75%) underwent a single session of RAE, while 6 patients (25%) had two or more sessions of RAE. The level of embolisation was feeder, segmental artery, and main renal artery in 28 (90%), 2 (6%), and 1 (4%) procedures, respectively. Coil, n-butyl 2-cyanoacrylate, and polyvinyl alcohol were the most frequently chosen embolic materials and were used in 19, 14, and 8 procedures, respectively. The clinical success rate after initial RAE was 67% (16/24). Overall clinical success rate, including multisession RAE, was 88% (21/24). The technical success rate of 31 procedures was 65% (20/31). Among 11 technical failures in 10 patients, 4 achieved clinical success without additional RAE, 3 underwent second session RAE to achieve clinical success, and 3 patients underwent nephrectomy due to recurrence. CONCLUSION: RAE is a safe and effective treatment for renal AVM. Technical failure of RAE does not always lead to clinical failure and multiple embolisation sessions may be effective for recurrent renal AVM.

Angiographic evaluation of hepatic arterial injury after cisplatin and Gelfoam-based transcatheter arterial chemoembolization for hepatocellular carcinoma in a 205 patient cohort during a 6-year follow-up.

OBJECTIVE: To evaluate the overall and cumulative incidence, degree, interval change and predictors of hepatic arterial injury (HAI) after cisplatin and Gelfoam® (Upjohn, Kalamazoo, MI)-based transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). METHODS: A total of 205 patients with HCC who underwent three or more sessions of TACE without additional surgical or local treatment were included. HAI was evaluated at each segment of the hepatic artery using a three-grade scale: 1 (slight wall irregularity), 2 (overt stenosis) and 3 (occlusion). HAI interval change was categorized into three groups: progression, stable state and improvement. Cumulative incidence of HAI was analysed using Kaplan- Meier method, and predictors of HAI (patient age, sex, portal vein thrombosis and Child-Pugh classification) were analysed by univariate logistic regression. RESULTS: HAI occurred in 50 of the 205 study patients (24.4%). The cumulative incidence of HAI was 16.0% [95% confidence interval (CI), 10.21-21.77] during 5 sessions of TACE, 52.1% (95% CI, 37.83-66.29) during 10 sessions and 68.0% (95% CI, 67.62-88.46) during 15 sessions. Initial HAI was interpreted as grades 1, 2 and 3 in 11 (22.0%), 17 (34.0%) and 22 (44.0%) patients, respectively. When the interval change was assessed in 48 patients with available follow-up TACE, 40 (83.3%) were included in the progression, 2 (4.2%) in the stable state and 6 (12.5%) in the improvement groups. The univariate analysis used to determine the predictors of HAI revealed no significant predictors. CONCLUSION: In three or more sessions of TACE, the incidence of HAI was 24%. Increasing TACE causes increased incidence of HAI. The initial presentation was most commonly grade 3, and 12.5% of the patients with HAI showed improvement of the HAI grade during follow-up TACE. ADVANCES IN KNOWLEDGE: In patients who underwent three or more sessions of cisplatin and Gelfoam-based TACE, the overall incidence of HAI was 24.4%, and increasing TACE causes increased incidence of HAI.

Incidence and management of postoperative abdominal bleeding after liver transplantation.

PURPOSE: To assess the incidence and management of postoperative abdominal bleeding after orthotopic liver transplantation (OLT) and to identify risk factors for abdominal bleeding. METHODS: We retrospectively reviewed the medical records of 1039 patients who underwent OLT at our institution from January 2008 to December 2010 seeking to identify subjects with posttransplantation abdominal bleeding, defined as any hemorrhage requiring radiologic intervention or laparotomy within the first month. RESULTS: Among the 1039 patients, 94 (9%) showed abdominal bleeding, occurring at a mean of 6.1 days (range, day 1 to 21 days). Active bleeding was controlled by endovascular interventional techniques (n = 37; 39%), by surgical ligation or vascular reconstruction (n = 43; 46%), or by sequential combinations of endovascular intervention and surgery (n = 14; 15%). The most frequent bleeding sites for radiologic intervention were the right inferior phrenic artery (n = 14), right and left epigastric arteries (n = 7), intercostal artery (n = 5) and right renal capsular artery (n = 4). The most frequent bleeding sites requiring laparotomy were the hepatic artery (n = 9), diaphragm (n = 8), inferior vena cava (n = 5), abdominal drain insertion site (n = 4), portal vein anastomosis site (n = 4), abdominal wall (n = 3), liver graft cut surface (n = 3), hilar plate (n = 3), and greater omentum (n = 3). Bleeding episodes were associated with greater patient age and increased intraoperative blood loss. CONCLUSIONS: The risk of bleeding from coagulopathy and iatrogenic injury is high during the early posttransplantation period. This risk of bleeding can be minimized by meticulous surgical dissection and bleeding control.

Persistent or recurrent varicocoele after failed varicocoelectomy: outcome in patients treated using percutaneous transcatheter embolization.

AIM: To determine the efficacy of percutaneous transcatheter embolization in the management of patients with spermatic varicocoeles persisting or recurring after surgery. MATERIALS AND METHODS: Over a period of 10 years, 28 patients (age range 13-55 years) were referred for percutaneous transcatheter embolization of postsurgical, recurrent varicocoeles. Medical documents were retrospectively reviewed to evaluate past surgical history, subjective symptoms, and results of scrotal examination, ultrasound, and semen parameters. Pre-embolization venograms were analysed to assess the anatomy of the testicular vein. The technical and clinical outcomes of embolization were then determined. RESULTS: The 28 patients included in the study had undergone laparoscopic varicocoelectomy (39.3%), high retroperitoneal ligation (25%), or inguinal ligation (25%). Subjective symptoms were scrotal pain (60.7%) and a palpable scrotal mass (50%) exclusively on the left side. Venograms revealed abnormalities of the left testicular vein in all cases. Embolization was technically successful in all but two cases, thus yielding an occlusion rate of 93%; a single case of suspected thrombophlebitis was the only complication. After excluding two, technically unsuccessful cases and one patient who was lost to follow-up, 25 patients underwent scrotal examination after embolization, which revealed complete resolution in 20 cases (80%), partial improvement in four cases (16%), and no improvement in a single case (4%). Among the follow-up group of patients, of the 12 who initially presented with scrotal pain, six (50%) were symptom-free and four (33.3%) had partial improvement. CONCLUSION: Percutaneous transcatheter embolization of the testicular vein is technically feasible and effective for managing postsurgical recurrent varicocoeles.

Effect of splenic artery embolization for splenic artery steal syndrome in liver transplant recipients: estimation at computed tomography based on changes in caliber of related arteries.

PURPOSE: To estimate the effect of splenic artery embolization (SAE) on blood flow in orthotopic liver transplantation (OLT) recipients with splenic artery steal syndrome (SASS) based on changes in caliber of related arteries upon serial computed tomography (CT) scans. METHODS: Between 2004 and 2007, nine OLT recipients with SASS underwent SAE. They had CT scans before and after SAE: short-, mid-, and long-term, ie, approximately 1 week, 1 month, and 1 year, respectively. The diameters of the celiac axis (CA), common hepatic artery (CHA), and splenic artery (SA) were measured with arterial phase of each CT scan and the ratios of SA to CHA diameter (SA/CHA) calculated to analyze their changes during the follow-up period. RESULTS: The diameters of celiac axis, CHA, and SA and SA/CHA changed most rapidly during the short-term period. The CHA diameter significantly increased short-term post-SAE by CT and slightly decreased thereafter. However, the mid-term and long-term post-SAE CT values were still significantly greater than those on the pre-SAE CT. The SA diameter steadily decreased throughout the follow-up. The SA/CHA decreased until the mid-term. The SA diameter and SA/CHA were significantly smaller upon mid-term and long-term post-SAE CT compared with those at pre-SAE CT. CONCLUSIONS: The effect of SAE to improve hepatic arterial flow in OLT recipients with SASS might be expected for at least approximately one year. The effect maximally occurred during the short-term after SAE on the basis of changes in the caliber of related arteries upon CT.

Transcatheter arterial chemo-lipiodol infusion for unresectable hepatocellular carcinoma in 96 high-risk patients.

AIM: To evaluate the safety and efficacy of transcatheter arterial chemo-lipiodol infusion (TACL) in high-risk patients with unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS: From January 2005 to April 2009, 96 patients underwent TACL. All patients had diffuse, infiltrative or multifocal tumours. Twenty-nine (30%) patients had an increased serum bilirubin level (>or=2mg/dl), and 75 patients (78%) had a low serum albumin level (<3.5mg/dl). The Child-Pugh (CP) score was 9 or more in 13 (14%) patients. Sixty-five patients (68%) had major portal vein occlusion. Sixteen patients (17%) had biliary dilatation. RESULTS: TACL was technically successful in all patients. After TACL, 18 (19%) of the 96 patients showed tumour response using computed tomography (CT) criteria. The 30 day mortality and morbidity rates were 1 and 2%, respectively. The median survival period was 8.6 months, and the overall 6 month, 1, 2, and 3 year survival rates were 59, 44, 26, and 15%, respectively. Portal vein occlusion (p<0.001) was the only significant risk factor associated with the length of the survival period after TACL, whereas the CP score (p=0.498), serum bilirubin level (p=0.153), serum albumin level (p=0.399), and biliary obstruction (p=0.636) had no significant effect. CONCLUSIONS: TACL can be performed safely in high risk HCC patients resulting in a median survival rate of 8.6 months in the present series.

Volumetric analysis of the liver after right portal vein embolization: mid-term follow-up based on embolization score.

AIM: To evaluate liver volume alterations and liver function after right portal vein embolization (PVE) during mid-term follow-up based on embolization score. MATERIALS AND METHODS: Computed tomography (CT) images and liver function profiles were obtained before PVE, and at short-term (7-45 days), and mid-term follow-up (106-380 days) after PVE in all 30 patients. The patients were divided into group A (PVE score >or=3, n=20) and group B (PVE score <3, n=10). High score indicates more complete embolization. RESULTS: Left liver volume (LLV) and percentage future liver remnant (%FLR) increased significantly between pre-PVE and short-term follow-up and between short-term and mid-term follow-up in group A. Increase in FLR volume was significantly higher at the mid-term follow-up than at the short-term follow-up in group A. The ratio of embolized to total liver volume (RETLV) on short-term follow-up was significantly higher in group A than in group B. Aspartate transaminase (AST) and alanine transaminase (ALT) were elevated on short-term follow-up, whereas at mid-term follow-up in group A, they had significantly returned to the baselines. CONCLUSION: PVE resulted in continued compensatory hypertrophy of the unembolized liver during the 6-month follow-up. Compensatory hypertrophy in the unembolized liver was proportional to the ratio of embolization and to the embolized liver volume.

Primary hepatic angiosarcoma: imaging findings and palliative treatment with transcatheter arterial chemoembolization or embolization.

AIM: To describe the image findings and results of transcatheter arterial chemoembolization (TACE) or transcatheter arterial embolization (TAE) for treating primary hepatic angiosarcoma. MATERIALS AND METHODS: A retrospective review of the electronic medical database from 2002 to 2007, revealed six patients with primary hepatic angiosarcoma confirmed by percutaneous liver biopsy. The computed tomography (CT) and angiography imaging findings, the TACE or TAE results, and the post-procedure course were evaluated in all patients. RESULTS: On CT and angiography, each tumour appeared as a solitary mass or as multiple nodules or masses with heterogeneously early and progressive enhancement. One of the two patients with tumour response to TACE died 8 months after initial presentation, and the remaining patient was still alive at the last follow-up 12 months after initial presentation. However, two patients with no response to TACE and two patients who underwent emergent TAE for tumour rupture died 1 week to 5 months (mean 2.1 months) after initial presentation. CONCLUSIONS: Primary hepatic angiosarcoma appears as a solitary or multiple, hypervascular lesions with heterogeneously early and progressive enhancement on CT and angiography. Although TAE may be the primary procedure for achieving emergent bleeding control caused by the rupture of hepatic angiosarcomas, TACE may be effective for treating patients with a dominant hepatic angiosarcoma with or without intrahepatic metastases.

Conservative management of symptomatic spontaneous isolated dissection of the superior mesenteric artery.

BACKGROUND: Spontaneous isolated dissection of the superior mesenteric artery (SMA) is uncommon. Because of its rarity, the risk factors, aetiology and natural history are unclear, and there is no consensus on the optimal treatment strategy. METHODS: Seven consecutive patients with symptomatic spontaneous isolated SMA dissection who received conservative treatment between March 2003 and February 2008 were included in this study. Their clinical characteristics, treatment methods and outcomes were analysed retrospectively. RESULTS: Acute abdominal pain was the most common clinical manifestation. Initial contrast-enhanced dynamic computed tomography (CT) showed isolated SMA dissection with partial thrombosis in all seven patients. Full anticoagulation was carried out immediately after the diagnosis. Clinical symptoms disappeared within 14 days and follow-up CT showed complete resolution of the dissection in four patients. After a mean follow-up of 23 months, there was no mortality or morbidity related to the dissection. CONCLUSION: In patients with symptomatic spontaneous isolated dissection of the SMA, conservative management is feasible if there is no evidence of bowel infarction or bleeding.

Transcatheter arterial chemoembolization vs. chemoinfusion for unresectable hepatocellular carcinoma in patients with major portal vein thrombosis.

BACKGROUND: Transcatheter arterial chemoembolization (TACE) has been limited in palliative treatment of unresectable hepatocellular carcinoma (HCC) with major portal vein (PV) invasion due to the possibility of liver failure following embolization. Transcatheter arterial chemoinfusion (TACI) has been an option in such cases. AIM: To compare clinical outcomes after TACE vs. TACI in HCC patients with major PV occlusion. METHODS: We compared clinical outcomes after TACE vs. TACI in HCC patients with major PV occlusion. From 2005 to 2007, 110 HCC patients with major PV thrombosis were treated with TACE (n = 49) or TACI (n = 61). RESULTS: The morbidity rate was similar for both TACE (6.1%) and TACI (6.5%) patients, and complications were adequately managed using medical treatment. The Kaplan-Meier survival analysis showed that the survival period was significantly longer for the TACE group (median: 14.9 months) than for the TACI (median: 4.4 months) group (P < 0.001). There was a higher probability of death in the TACI group than in the TACE group in both our multivariate Cox-proportional hazards (OR 3.09, P < 0.001) and the propensity score-matched (27 pairs) cohort analyses (OR 2.27, P = 0.024). CONCLUSIONS: Transcatheter arterial chemoembolization can be safely performed in HCC patients with main PV occlusion. Compared with TACI, TACE may result in longer survival of HCC patients with major PV occlusion.

Percutaneous transluminal angioplasty of suture-mediated closure device-related femoral artery stenosis or occlusive disease.

This study evaluates the efficacy of percutaneous transluminal balloon angioplasty (PTA) to treat stenosis or occlusion following haemostasis using a suture-mediated closure (SMC) device. Steno-occlusion occurred in 7 (0.4%) patients, some with claudication, others without. Steno-occlusion was diagnosed immediately after haemostasis in the four patients without claudication, but diagnosis was delayed in all three patients with claudication. Six of the patients subsequently underwent PTA using a contralateral femoral arterial approach. Technical success, clinical response and vessel patency were evaluated retrospectively. Follow-up angiography revealed focal segmental steno-occlusion (<1 cm) in the common femoral or proximal superficial femoral artery in four patients and long segmental occlusion (>1 cm) in the external iliac and common femoral arteries in three patients. PTA was technically successful in all patients (6/6, 100%). Among the three patients who developed delayed onset of claudication, one declined treatment and the claudication improved in two. Doppler ultrasound obtained 28-129 days (mean; 75 days) after PTA revealed patent arterial flow in six patients. One patient with delayed-onset occlusion refused the procedure because the symptoms were mild. This study has shown that PTA is a useful treatment for steno-occlusion following haemostasis using the SMC device. Careful angiography and review of the femoral bifurcation prior to use of an SMC device is important.

A case of successful embolotherapy for gastric ulcer bleeding from the intercostal artery after oesophagectomy and gastric reconstruction.

We report a successful treatment with coil embolisation of an intercostal artery for ulcer bleeding in a gastric tube in a 70-year-old man who underwent a total oesophagectomy and gastric tube reconstruction for oesophageal cancer. This case teaches us to search aberrant feeding vessels when active bleeding is suspected in reconstructed gastric tube in the patient with oesophagectomy and oesophagogastrostomy.

Effect of irradiating shell eggs on quality attributes and functional properties of yolk and white.

Shell eggs were irradiated and the physico-chemical, and functional properties of egg yolk and white were determined. The color of egg yolk was not affected, but the viscosity of egg white was dramatically lowered and became watery by irradiation. The foam capacity and foam stability of egg white were significantly decreased due to protein oxidation by irradiation. However, the texture characteristics of egg white were not changed by irradiation, indicating that irradiation may not alter the thermal characteristics of egg white proteins. Sulfur volatiles were generated by irradiation but disappeared during storage under aerobic conditions. Because egg white became watery, irradiation may not be advisable for table eggs but may be useful for pasteurizing liquid egg white or liquid whole egg without significant deterioration of their quality and functionality. In particular, the dramatic decrease in the viscosity of egg white by irradiation will improve flow of liquid egg white or liquid whole egg, which could be highly useful for egg processing.

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.

Balloon dacryocystoplasty: results and factors influencing outcome in 350 patients.

PURPOSE: To evaluate the initial and long-term results of balloon dacryocystoplasty in the treatment of epiphora caused by obstruction of the lacrimal system with analysis of the procedure's favorable effects. MATERIALS AND METHODS: Four hundred thirty eyes of 350 patients with obstructions of the lacrimal system were enrolled. Dacryocystoplasty was performed with use of a balloon catheter and a ball-tipped guide wire. The lesions were categorized according to cause, severity, site of the obstruction, and diameter and inflation time of the balloon. The technical success, initial success (improvement of symptoms after 1 week), and long-term patency rates were calculated. These rates in each group were compared with the chi(2) test and the Kaplan-Meier method. RESULTS: The overall technical success rate was 95.3%. The overall initial success rate was 57.4%. There was no significant complication except for mild epistaxis in 12%. The 2-month, 1-year, and 5-year patency rates were 48.2%, 39.4%, and 36.9%, respectively. Initial success was influenced by the severity (P =.014) and the site (P <.001) of the obstruction, and the diameter of the balloon (P =.047). Long-term patency was affected by the site of the obstruction (P <.001) and the balloon inflation time (P <.001). Among the 183 initially ineffective and 88 recurrent cases, 62 underwent repeat balloon dacryocystoplasty, and the initial success rate was 38.7%. CONCLUSIONS: The initial success rate of balloon dacryocystoplasty is relatively low. However, long-term patency can be expected in cases with initial success. Some additional factors also should be considered for better results.

Circadian regulation of cGMP-gated cationic channels of chick retinal cones. Erk MAP Kinase and Ca2+/calmodulin-dependent protein kinase II.

cGMP-gated channels are essential for phototransduction in the vertebrate retina. Here we show that the affinity of these channels for cGMP in chick cones is substantially higher during the subjective night than during the subjective day. This effect persists in constant environmental conditions after entrainment to 12:12 hr light-dark cycles in vitro or in ovo. Circadian modulation of ligand affinity is a posttranslational effect and is driven by rhythms in the activities of two protein kinases: Erk and Ca2+/calmodulin-dependent protein kinase II (CaMKII). Erk is maximally active during the subjective night, whereas CaMKII is maximally active during the subjective day. Acute inhibition of these signaling pathways causes phase-dependent changes in the affinity of the channels for cGMP.