Right and left ventricular volume characteristics in children with transposition of the great arteries after Mustard's procedure

With use of biplane cine-angiocardiograms, the measurements of right and left ventricular volume were determined in 11 children with transposition of the great arteries following Mustard's procedure. Right ventricular end-diastolic volume (RVEDV) ranged from 124 to 264 percent of the normal right ventricular volume with an average of 188 +/- 40 (SDM) percent, and left ventricular end-diastolic volume (LVEDV) ranged from 57 to 181 (122 +/- 43) percent of the normal (p less than 0.01, vs. RVEDV). Right ventricular ejection fraction (RVEF) ranged from 0.26 to 0.66 (0.42 +/- 0.11), and left ventricular ejection fraction (LVEF) ranged from 0.51 to 0.79 (0.66 +/- 0.09) (p less than 0.001, vs RVEF). Left ventriculography showed a deviation of the interventricular septum toward the left ventricle in patients with simple transposition of the great arteries not associated with left ventricular hypertension. The left to right ventricular systolic pressure ratio ranged from 0.22 to 1.02 (0.48 +/- 0.28), and the left to right ventricular end-diastolic volume ratio ranged from 0.43 to 1.00 (0.63 +/- 0.18). There was a high correlation between the left to right ventricular systolic pressure ratio and the left to right ventricular end-diastolic volume ration (r = 0.94, p less than 0.001). The left to right ventricular systolic pressure ratio also correlated well with the right ventricular ejection fraction (r = 0.90, p less than 0.001). Deviation of the interventricular septum was considered to result in a diminished ejection fraction of the right ventricle, in patients with simple transposition of the great arteries not associated with left ventricular hypertension, after Mustard's procedure.     

Detection of Suction and Regurgitation of the Implantable Centrifugal Pump Based on the Motor Current Waveform Analysis and Its Application to Optimization of Pump Flow

In this study, a detection algorithm for suction and regurgitation of the centrifugal pump during left heart bypass without relying on external flow or pressure sensors was developed and evaluated in acute studies using adult goats. The detection scheme relies on power spectral density (PSD) analysis of the motor current waveform through which the waveform deformation index (WDI) is obtained. This index is defined as the ratio of the fundamental component of the PSD to the higher PSD components, and its value increases with the deformation of the basic waveform. By assuming that the undistorted motor current waveform can be represented by a pure sine waveform, we theoretically synthesized various waveforms which have different second harmonic components. We were able to synthesize the waveform whose shape was close to the distorted motor current waveform under varying suction levels obtained in a mock loop study. From this study, we came to the conclusion that the WDI value of 0.2 can serve as a threshold level in deciding the suction and regurgitation speeds (rpm) during left heart bypass. In the study using adult goats, we were successful in minimizing both regurgitation and suction when the centrifugal pump speed was adjusted based on the WDI algorithm. The resultant bypass flow ranged from 1.5 to 2.0 L/min which was around 60% of the total flow. Further study is underway to evaluate the applicability of the WDI method in optimizing bypass pump flow.     

The usefulness of transcatheter arterial embolization for patients with blunt polytrauma showing transient response to fluid resuscitation

BACKGROUND: This study aimed to determine whether nonsurgical management using transcatheter arterial embolization (TAE) is safe for patients with blunt multiple trauma who transiently respond to the initial fluid resuscitation. METHODS: Contrast computed tomography was performed for patients with blunt abdominal injuries, excluding those who did not respond to initial fluid resuscitation. Angiography was performed for patients with injuries showing contrast extravasation or solid organ injury classified, according to the American Association for the Surgery of Trauma, as grade 3 or higher on computed tomography. Transcatheter arterial embolization was performed when angiography showed arterial extravasation. The protocol was abandoned for any patients who became profoundly hypotensive (with systolic blood pressure 60 mm Hg or lower) during computed tomography or angiography. RESULTS: Between January 2000 and December 2002, 269 patients with blunt abdominal injuries underwent TAE immediately after admission. Of these patients, 41 had injuries in at least two regions and underwent TAE for these regions. Among them, 22 patients were hemodynamically stable or showed rapid response to fluid resuscitation. The nonsurgical treatment was successful in all these cases. The remaining 19 patients (Injury Severity Score, 37.3 +/- 8.2), who showed a transient response, were the subjects of this study. Of these patients, 15 underwent TAE for injuries in two regions (13 pelvic fractures, 7 splenic injuries, 6 hepatic injuries, 3 facial bleeding, and 1 renal injury), and 4 patients underwent TAE for injuries in three regions (4 had splenic injuries, 3 hepatic injuries, 2 renal injuries, 2 pelvic fractures, and 1 facial bleeding). For all these patients, TAE was successfully performed. Before TAE, the systolic blood pressure was 79.9 +/- 8.4 mm Hg, and the shock index was 1.45 +/- 0.25 mm Hg. After TAE, the corresponding values were 120.6 +/- 19.3 mm Hg and 0.87 +/- 0.16 mm Hg, respectively (p < 0.001). The rate of fluid administration required after TAE (214.2 +/- 139.3 mL/hour) was significantly less than that required before TAE (1244.2 +/- 347.1 mL/hour; range, 632-1,728 mL/hour) (p < 0.001). The deaths of two patients were classified as nonpreventable on the basis of the Trauma and Injury Severity Score (TRISS), and their respective probabilities of survival were determined to be 0.13 and 0.03. CONCLUSION: Nonsurgical management using TAE can be performed safely even for patients with blunt multiple trauma who are in hemorrhagic hypotension if their hemodynamics are improved by resuscitation with 2 L of fluid.     

Receptor activator of NF-κB ligand-dependent expression of caveolin-1 in osteoclast precursors, and high dependency of osteoclastogenesis on exogenous lipoprotein

Although extensive studies have done much to clarify the molecular mechanisms of osteoclastogenesis during the last ten years, there may still be unknown molecules associated with osteoclast differentiation. Thus, we used fluorescent differential display to screen for genes whose expression is induced by receptor activator of NF-κB ligand (RANKL), a crucial molecule for osteoclast formation. We identified caveolin-1 (Cav-1) as a RANKL-induced gene. Cav-1 is a major structural protein of caveolae and lipid rafts, cholesterol-enriched microdomains in the plasma membrane (PM). The RANKL-induced Cav-1 was immediately conveyed to lipid rafts. Conversely, expression of flotillin-1 (Flot-1), another scaffolding protein of lipid rafts, was reduced during osteoclastogenesis, indicating conversion of Flot-1-predominant rafts into Cav-1-enriched rafts. However, in vitro osteoclastogenesis of precursor cells from Cav-1-null mice was comparable to that of wild-type mice, while Cav-2 expression in the knockout osteoclasts was maintained. Conversely, Cav-2 gene silencing in Cav-1-null osteoclast precursors using siRNA for Cav-2 increased osteoclast formation, suggesting that the Cav-1/Cav-2 complex may act as a negative regulator for osteoclastogenesis. On the other hand, destruction of lipid rafts by removal of cholesterol from the PM by methyl-ß-cyclodextrin (MCD) treatment caused disordered signal transductions for osteoclastogenesis, such as hyperactivation of Erk1/2 and insensitivity of Akt to RANKL stimulus. The abnormal signaling was reproduced by deleting exogenous lipoproteins from the culture medium, which also resulted in reduced osteoclast formation. In addition, the deletion caused delayed expression of nuclear factor of activated T cells c1 (NFATc1), and depressed its activation in the cytosol and inhibited its translocation into nuclei. Simultaneously, the deletion reduced the level of FcRγ, a trigger protein for initiating the calcium signaling needed to activate NFATc1, and decreased Cav-1 in lipid rafts. These findings indicate that the molecular mechanisms of osteoclastogenesis are highly dependent on extracellular lipoprotein and the integrity of lipid rafts, and suggest possible involvement of cholesterol.     

Evaluation of complications related to therapeutic colonoscopy using the bipolar snare

Background

The complications with therapeutic colonoscopy reported to date have been associated with the monopolar snare, and the frequency of complications related to use of the bipolar snare is uncertain. This study aimed too investigate the incidence of bleeding and perforation associated with the bipolar snare and to identify the risk factors for bleeding.

Methods

Between October 2001 and December 2008, all patients with colorectal polyps treated using the bipolar snare were enrolled in this retrospective study. Clinical data were assembled from an electronic database. The incidence of bleeding and perforation was investigated, and the risk factors for bleeding also were determined using multivariate analysis.

Results

This study collected 4,719 patients with 10,513 lesions. Perforation occurred for eight patients (0.17%) and bleeding in 66 patients (1.4%). Age younger than 60?years was a significant risk factor for bleeding (P?P?P?P?P?Conclusions The complication rates for the bipolar snare appear to be comparable with those for the monopolar snare based on comparison of the results reported in the literature. Age (<60?years), lesion size (??10?mm), macroscopic type (pedunculated), and lesion location (rectum) are independent risk factors for bleeding.     

Rectovaginal fistulas after rectal cancer surgery: Incidence and operative repair by gluteal-fold flap repair

BACKGROUND: We investigated the correlation between operative procedures for rectal carcinoma and postoperative rectovaginal fistulas (RVF), and treatment for RVF. METHODS: The medical records of 161 female patients with rectal carcinoma were examined retrospectively with respect to the cause, incidence, and methods of treatment for RVF occurring after rectal cancer operations, and to the outcomes of gluteal-fold flap repairs for RVF. RESULTS: Of the 161 patients, 16 developed RVF clinically. The incidence of RVF was significantly higher in patients who were anastomosed by the double stapling technique (DST) and had concomitant resection of the vaginal wall. No statistical difference was found between the established diverting ostomy group and the no-stoma group. Six patients recovered by the establishment of a diverting ostomy only. The gluteal-fold flap technique was performed for 5 patients. No RVF recurrences were noted in these 5 patients. CONCLUSIONS: The incidence of RVF was higher in the patients who were anastomosed by DST or had concomitant resection of the vaginal wall. Although some RVFs heal with only fecal diversion, for patients in whom RVF is caused by involvement of the vaginal wall in the circular staple or intersphincteric resection, good results are obtained with the gluteal-fold flap repair technique.     

Partial splenic embolisation using n-butyl cyanoacrylate: intraprocedural evaluation by magnetic resonance imaging

Objectives

To evaluate the use of diffusion-weighted imaging (DWI) for estimating infarcted splenic volume during partial splenic embolisation (PSE) using n-butyl cyanoacrylate (NBCA).

Methods

Twenty consecutive patients (57.2?±?11.7 years) with hypersplenism underwent PSE. Intrasplenic branches were embolised using NBCA via a 2.1-French microcatheter aiming at infarction of 50 to 80 % of total splenic volume. Immediately after PSE, signal intensities (SI) of embolised and non-embolised splenic parenchyma were measured on DWI. Semi-automated volumetry (SAV) on DWI was compared with conventional manual volumetry (MV) on contrast-enhanced CT 1 week after PSE. Platelet counts were recorded before and after PSE.

Results

The SI on DWI in the embolised parenchyma decreased significantly (P?<?0.01) to 24.7?±?8.1 % as compared to non-embolised parenchyma. SAV and MV showed a strong correlation (r?=?0.913 before PSE, r?=?0.935 after PSE, P?<?0.01) and significant (P?<?0.01) reduction of normal splenic volume was demonstrated on both SAV (71.9?±?12.4 %) and MV (73.6?±?9.3 %) after PSE. Based on the initial SAV, three patients (15 %) underwent additional branch embolisation to reach sufficient infarction volume. Platelet counts elevated significantly (522.8?±?209.1 %, P?<?0.01) by 2 weeks after PSE. No serious complication was observed.

Conclusion

Immediate SI changes on DWI after PSE allowed semi-automated splenic volumetry on site.

Key Points

? Partial splenic embolisation (PSE) is an important interventional technique for hypersplenism ? Diffusion-weighted MR reveals an immediate decrease in signal in the embolised parenchyma ? Such signal reduction permits semi-automated splenic volumetry on site. ? This allows precise quantification of the amount of parenchyma infarcted, avoiding additional PSE.     

Delayed radiation necrosis with extensive brain edema after gamma knife radiosurgery for multiple cerebral cavernous malformations--case report

A 39-year-old man presented with multiple intracranial cavernous malformations manifesting as intractable seizures persisting for more than 20 years. He underwent gamma knife radiosurgery (GKRS) for right frontal and left temporal cavernous malformations. He began to suffer from progressive left hemiparesis and inattention 2 years 5 months after the GKRS. Magnetic resonance imaging showed abnormal ring enhancement and extensive brain edema around the right frontal lesion. Conservative therapies such as external decompression, low-dose barbiturates, and mild hypothermia had no effect on his clinical status. Stereotactic biopsy of the ring-enhanced area demonstrated gliosis. Signs of cerebral herniation appeared, so we performed partial resection of the right frontal lobe. His symptoms recovered immediately. Subsequent hyperbaric oxygen (HBO) therapy significantly improved the extensive brain edema. Delayed radiation necrosis associated with potentially fatal brain edema may occur after GKRS for cavernous malformations. Internal decompression and subsequent HBO therapy were very effective for the treatment of these lesions.     

Reconstruction methods to achieve optimal postoperative bowel function following low anterior resection for rectal cancer

After low anterior resection for rectal cancer, approximately 50% of patients experience defecatory malfunction such as multiple evacuations, urgency, and soiling. Since the neorectum is constructed with the remaining colonic segment, it can only substitute for the rectum to a limited extent. A straight anastomosis is most frequently used when the rectal remnant is sufficient, such as in high anterior resection. When the height of anastomosis is close to the anal sphincter, a J-pouch, a side-to-end, or a transverse coloplasty pouch are constructed to achieve better postoperative bowel function. The advantage of J-pouch reconstruction is not only the increased volume but also may be decreased motility when compared with straight reconstruction. In terms of postoperative function, the side-to-end and transverse coloplasty pouch have both been reported to exhibit similar functional results to J-pouch reconstruction. To obtain optimal functional results, pouch reconstruction should be considered, especially when the height of anastomosis is at the levator plane.     

Cardiac anesthesia induction by low target plasma concentration setting of propofol using target-controlled infusion

BACKGROUND: Propofol-anesthesia administerd using target-controlled infusion (TCI) has been proposed for cardiac surgery. But, moderate target concentration of propofol during induction using TCI has not been studied in detail. METHODS: Thirty patients scheduled for cardiac surgery under cardiopulmonary bypass (CPB) and TCI propofol anesthesia were randomly divided into two groups to receive a computer-controlled infusion of propofol with target concentrations of 1.5 or 2.0 micro/g x ml(-1) [1.5 microg x ml(-1) group (n=15) and 2.0 microg x ml(-1) group (n=15)]. Mean arterial pressure (MAP), heart rate (HR) and bispectral index scale (BIS) values were recorded at 5 time points during induction of anesthesia. RESULTS: MAP was significantly lower in 2.0 microg x ml(-1) group compared with 1.5 microg x ml(-1) group. In both groups, a rise of BIS value did not occur during tracheal intubation. CONCLUSIONS: We have demonstrated that propofol TCI at a target concentration of 1.5 microg x ml(-1) is effective for hemodynamic stability during induction of anesthesia in patients for cardiac surgery under CPB.