Thrombophilic dysfibrinogen Tokyo V with the amino acid substitution of gammaAla327Thr: formation of fragile but fibrinolysis-resistant fibrin clots and its relevance to arterial thromboembolism

Thrombophilic dysfibrinogen Tokyo V was identified in a 43-year-old man with recurrent thromboembolism. Based on analyses of the patient fibrinogen genes, the amino acid sequence of the aberrant fibrinogen peptide, and deglycosylation experiments, fibrinogen Tokyo V was shown to have an amino acid substitution of gamma Ala327Thr and possibly extra glycosylation at gamma Asn325 because the mutation confers the N-linked glycosylation consensus sequence Asn-X-Thr. The mutation resulted in impaired function and hypofibrinogenemia (hypodysfibrinogen). Polymerization of fibrin monomers derived from patient fibrinogen was severely impaired with a partial correction in the presence of calcium, resulting in very low clottability. Additionally, a large amount of soluble cross-linked fibrin was formed upon thrombin treatment in the presence of factor XIII and calcium. However, Tokyo V-derived fibrin was resistant to degradation by tissue plasminogen activator (tPA)-catalyzed plasmin digestion. The structure of Tokyo V fibrin appeared severely perturbed, since there are large pores inside the tangled fibrin networks and fiber ends at the boundaries. Taken together, these data suggest that Tokyo V fibrin clots are fragile, so that fibrinolysis-resistant insoluble fibrin and soluble fibrin polymers may be released to the circulation, partly accounting for the recurrent embolic episodes in the patient.     

Incidence and clinical characteristics of chronic pulmonary thromboembolism in Japan compared with acute pulmonary thromboembolism: results of a multicenter registry of the Japanese Society of Pulmonary Embolism Research.

The incidence of acute pulmonary thromboembolism (APTE) in Japan is quoted as being extremely low compared with the United States, and the incidence and clinical characteristics of chronic pulmonary thromboembolism (CPTE) in Japan is unknown, so this study investigated these aspects of CPTE in 309 patients with APTE and 68 patients with CPTE. The ratio of the incidence of CPTE to APTE was 0.22 and there was no significant difference in age or sex between the APTE and CPTE patients. All of the predisposing factors for pulmonary thromboembolism, except for thrombophilia, were more frequently seen in the patients with APTE. There are some differences in the incidence and clinical characteristics of CPTE compared with APTE between Japanese and American patients in Japan, suggesting that the pathogenesis of CPTE in Japan may differ from that in the USA.     

Liver metastasis of rectal cancer with intraluminal growth in the extrahepatic bile duct

Metastatic liver tumors are considered to have a tendency for expansive growth and rarely invade the bile duct. We recently encountered a resected case of liver metastasis from rectal cancer with intraluminal growth in the extrahepatic bile duct with a successful left trisegmentectomy of the liver. A 54-year-old woman underwent a posterior total pelvic exenteration for advanced rectal cancer. Ultrasonography and computed tomography four months after the first operation demonstrated a solitary occupied lesion in the liver with dilation of the left hepatic duct. Endoscopic retrograde cholangiopancreatography disclosed a filling defect in the intra- to extrahepatic bile duct. Liver metastasis from rectal cancer with intraluminal growth in the bile duct was suspected despite a consideration of primary bile duct cancer. A left trisegmentectomy of the liver and resection of the extrahepatic bile duct with a right hepatojejunostomy were performed. The tumor had invaded the intrahepatic bile duct and had developed intraluminally in the extrahepatic bile duct. Tumor thrombi were microscopically found in the bile duct of the left caudal lobe. Liver metastasis arising from colorectal cancer with intraluminal growth in the bile duct is rare, however we encountered such a case with a successful resection involving a left trisegmentectomy of the liver.     

The resection of non-hepatic intraabdominal recurrence of gastric cancer

BACKGROUND/AIMS: Surgical resection of hepatic or pulmonary metastases from gastrointestinal cancer has been recognized as a curative modality in some patients. However, the role and outcome of the surgical management of a non-hepatic intraabdominal recurrence of gastrointestinal cancer have not been clearly delineated. METHODOLOGY: We treated 5 patients for non-hepatic intraabdominal recurrence of gastric carcinoma surgically. All the resected specimens were microscopically identified as recurrent gastric cancer. Three of 5 patients received postoperative chemotherapy. The clinicopathological findings were analyzed according to the general rules for gastric cancer study. RESULTS: The lymph nodes were dissected for lymph node metastases. Surgical resection of the tumors combined with total gastrectomy, esophagectomy, or colectomy was performed for the local and peritoneal recurrences. All of the recurrent tumors were macroscopically resected with curative states. One patient died of sepsis 54 days after surgery. Three patients died of recurrent gastric cancer: 2 within 1 year of surgery and 1 after 3 years. One patient still survives disease free 3 years and 6 months after the 2nd operation. CONCLUSIONS: Surgical resection for non-hepatic intraabdominal recurrence of gastric cancer is the treatment of choice for selected patients. Surgical resection followed by adjuvant chemotherapy may improve the outcome of these patients.     

Intrapulmonary bronchial blood flow of rats as studied by the microsphere method

Summary The intrapulmonary bronchial blood flow of the left lung (systemic arterial blood flow to the left lung via the bronchial artery) was determined in 45 anesthetized and artificially ventilated male Wistar rats, weighting 263±5 g (mean ± SEM). The microsphere method was employed and designed so that recirculating microspheres across the peripheral arteriovenous anastomoses were prevented from lodging in the left lung, and disturbances of the isovolemic state of the animals became minimal. Under normal conditions with a mean arteiral pressure of 115±2 mmHg (n=40), the bronchial blood flow of the left lung was found to be 0.307±0.033 ml/min on average, and amounted to 0.52±0.06% of the cardiac output. The flow (ml/min) normalized per kg body weight, 100 g wet lung, or 100 g dry lung was 1.14±0.12, 76±8, or 368±39, respectively. The total intrapulmonary bronchial blood flow of the left and right lungs could be estimated by multiplying the intrapulmonary bronchial flow of the left lung by the weight ratio (total: left) of 2.9. The variability of the flow data was small, as confirmed in a study with simultaneous injection of two differently radiolabeled microspheres. The reproducibility of duplicate measurements was excellent.     

Pulmonary lobar root clamping and stapling technique: return of the “en masse lobectomy”

Purpose

Most thoracic surgeons have experienced difficulty dissecting the pulmonary hilus because of scarring. In such potentially dangerous situations, we advocate a method of clamping and severing the pulmonary lobar root structure en masse. The aim of this study was to evaluate en masse lobectomy, particularly considering the constellation of pulmonary vessels and the bronchus.

Methods

Twelve patients (median age 70 years) underwent en masse lobectomy. We retrospectively evaluated the surgical procedures and clinical outcomes. Care was taken to consider the remaining vessels and bronchus, which regulate the direction of device placement.

Results

Seven patients had inflammatory lung disease, four had primary pulmonary carcinoma, and one had suffered blunt chest trauma. Ten operations were elective and two were emergent. Lobectomy included the right upper lobe in two cases, the right middle lobe in three, the right lower lobe in two, the right middle-lower lobe in two, and the left lower lobe in three. A stapler was used in ten patients, and sutures were applied in three (both were used in one case). Morbidities included a pyothorax and a persistent air leak; both made a recovery. Mortality included one emergency case of acute respiratory distress syndrome. No bronchopleural or bronchovascular fistulas occurred.

Conclusions

We believe that the en masse lobectomy is an alternative and necessary technique in critical or unexpected situations, possibly as a last resort. Trauma and severe inflammation may be good indications for en masse lobectomy.     

Surgical device exchange provides improved clinical outcomes compared to medical therapy in treating continuous-flow left ventricular assist device thrombosis

The purpose of this study is to compare clinical outcomes of left ventricular assist device (LVAD) patients with device thrombosis who underwent device exchange (DE) or medical therapy (MT) alone. Consecutive patients undergoing LVAD implant between July 2008 and December 2017 were included. Device thrombosis was diagnosed with comprehensive assessments including ramp test, laboratory data, device parameters, and clinical presentations. First, MT was initiated in all patients. After MT, DE was considered if device thrombosis was refractory to initial MT, and it caused end-organ impairment and/or hemodynamic instability. Among 319 consecutive LVAD patients, 43 patients (13.5%) were diagnosed with device thrombosis. DE was performed in 28 patients (DE group); device explant was performed in 1 patient. MT was continued in 14 patients (MT group). In-hospital mortality was significantly lower in the DE group than the MT group (3.6% [1/28] vs. 28.6% [4/14], P = .0184). One-year survival was significantly better in the DE group (74.0% vs. 30.1%; log-rank = .001), and freedom from cerebrovascular accident (CVA) at 1 year was greater in the DE group (87.1% vs. 47.7%; log-rank = .004). DE was associated with improved 1-year survival and fewer CVAs. Surgical intervention, if feasible, is recommended for LVAD device thrombosis.     

Optimal cannula positioning of HeartMate 3 left ventricular assist device

Cannula position in HeartMate II and HeartWare left ventricular assist devices (LVADs) is associated with clinical outcome. This study aimed to investigate the clinical implication of the device positioning in HeartMate 3 LVAD cohort. Consecutive patients who underwent HeartMate 3 LVAD implantation were followed for one year from index discharge. At index discharge, chest X-ray parameters were measured: (a) cannula coronal angle, (b) height of pump bottom, (c) cannula sagittal angle, and (d) cannula lumen area. The association of each measurement of cannula position with one-year clinical outcomes was investigated. Sixty-four HeartMate 3 LVAD patients (58 years old, 64% male) were enrolled. In the multivariable Cox regression model, the cannula coronal angle was a significant predictor of death or heart failure readmission (hazard ratio 1.27 [1.01-1.60], P = .045). Patients with a cannula coronal angle ≤28° had lower central venous pressure (P = .030), lower pulmonary capillary wedge pressure (P = .027), and smaller left ventricular size (P = .019) compared to those with the angle >28°. Right ventricular size and parameters of right ventricular function were also better in the narrow angle group, as was one-year cumulative incidence of death or heart failure readmission (10% vs. 50%, P = .008). Narrow cannula coronal angle in patients with HeartMate 3 LVADs was associated with improved cardiac unloading and lower incidence of death or heart failure readmission. Larger studies to confirm the implication of optimal device positioning are warranted.