On growth measurements of abdominal aortic aneurysms using maximally inscribed spheres

The maximum diameter, total volume of the abdominal aorta, and its growth rate are usually regarded as key factors for making a decision on the therapeutic operation time for an abdominal aortic aneurysm (AAA) patient. There is, however, a debate on what is the best standard method to measure the diameter. Currently, two dominant methods for measuring the maximum diameter are used. One is measured on the planes perpendicular to the aneurism's central line (orthogonal diameter) and the other one is measured on the axial planes (axial diameter). In this paper, another method called 'inscribed-spherical diameter' is proposed to measure the diameter. The main idea is to find the diameter of the largest sphere that fits within the aorta. An algorithm is employed to establish a centerline for the AAA geometries obtained from a set of longitudinal scans obtained from South Korea. This centerline, besides being the base of the inscribed spherical method, is used for the determination of orthogonal and axial diameter. The growth rate parameters are calculated in different diameters and the total volume and the correlations between them are studied. Furthermore, an exponential growth pattern is sought for the maximum diameters over time to examine a nonlinear growth pattern of AAA expansion both globally and locally. The results present the similarities and discrepancies of these three methods. We report the shortcomings and the advantages of each method and its performance in the quantification of expansion rates. While the orthogonal diameter measurement has an ability of capturing a realistic diameter, it fluctuated. On the other hand, the inscribed sphere diameter method tends to underestimate the diameter measurement but the growth rate can be bounded in a narrow region for aiding prediction capability. Moreover, expansion rate parameters derived from this measurement exhibit good correlation with each other and with growth rate of volume. In conclusion, although the orthogonal method remains the main method of measuring the diameter of an abdominal aorta, employing the idea of maximally inscribed spheres provides both a tool for generation of the centerline, and an additional parameter for quantification of aneurysmal growth rates.

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS): impact of the inter-stages course on morbi-mortality and implications for management

BACKGROUND

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) was recently developed to induce rapid hypertrophy and reduce post-hepatectomy liver failure in patients with insufficient remnant liver volume (RLV). However, mortality rates >12% have been reported. This study aimed to analyze the perioperative course of ALPPS and to identify factors associated with morbi-mortality.

METHODS

Between April 2011 and September 2013, 62 patients operated in 9 Franco-Belgian hepatobiliary centres underwent ALPPS for colorectal metastases (N = 50) or primary tumors, following chemotherapy (N = 50) and/or portal vein embolization (PVE; N = 9).

RESULTS

Most patients had right (N = 31) or right extended hepatectomy (N = 25) (median RLV/body weight ratio of 0.54% [0.21-0.77%]). RLV increased by 48.6% [-15.3 to 192%] 7.8 ± 4.5 days after stage1, but the hypertrophy decelerated beyond 7 days. Stage2 was cancelled in 3 patients (4.8%) for insufficient hypertrophy, portal vein thrombosis or death and delayed to ≥9 days in 32 (54.2%). Overall, 25 patients (40.3%) had major complication(s) and 8 (12.9%) died. Fourteen patients (22.6%) had post-stage1 complication of whom 5 (35.7%) died after stage2. Factors associated with major morbi-mortality were obesity, post-stage1 biliary fistula or ascites, and infected and/or bilious peritoneal fluid at stage2. The latter was the only predictor of Clavien ≥3 by multivariate analysis (OR: 4.9; 95% CI: 1.227-19.97; p = 0.025). PVE did not impact the morbi-mortality rates but prevented major cytolysis that was associated with poor outcome.

CONCLUSIONS

The inter-stages course was crucial in determining ALPPS outcome. The factors of high morbi-mortality rates associated with ALPPS are linked to the technique complexity.

Accessory liver lobes: anatomical description and clinical implications

Accessory liver lobes are a rare condition and appear to be due to excessive development of the liver. The presence of an accessory hepatic lobe is often diagnosed incidentally and sometimes revealed if it develops torsion, especially in pedunculated forms. In most cases, the accessory lobe is located below the liver, i.e., infrahepatic. Riedel's lobe is the best-known example of an accessory lobe, corresponding to hypertrophy of segments V and VI. While accessories lobes can simulate tumors, there have also been reports of hepatocellular tumor(s) that developed in these accessory lobes. Based on a review of the literature, this update focuses on accessory hepatic lobes.

The development and validation of the treatment of autoimmune bullous disease quality of life questionnaire, a tool to measure the quality of life impacts of treatments used in patients with autoimmune blistering disease

BACKGROUND

Treatments for autoimmune blistering diseases have significant risk of medical complications and quality of life impacts during treatment, and it is difficult to differentiate these impacts from disease burden or the effects of treatment.

OBJECTIVES

To develop a quality of life instrument specific to the effects of treatments used in patients with autoimmune bullous disease (AIBD).

METHODS

A comprehensive item generation process was used to build a 45-item pilot Autoimmune Bullous Disease Quality of Life (ABQOL) questionnaire, distributed to 70 patients with AIBD. Experts in bullous disease refined the pilot ABQOL, selecting only those questions pertaining to the treatment effects. This pilot Treatment of Autoimmune Bullous Disease Quality of Life (TABQOL) questionnaire was administered to 70 patients, before factor analysis was performed to yield the final questionnaire of 17 questions. Validity and reliability were evaluated across a range of indices.

RESULTS

Face and content validity were established through a comprehensive patient interview process, expert review and summaries of treatments used. The questionnaire was found to have appropriate correlation with the Dermatology Life Quality Index (r = 0.64) and the level of treatments used (P < 0.01), and was found to be responsive to overall variations in treatment burden. The TABQOL was also found to be a reliable instrument as evaluated by internal consistency (Cronbach α = 0.892) and test-retest reliability (r = 0.99).

CONCLUSIONS

We have shown that the TABQOL questionnaire is a valid and reliable instrument that may to be used to measure treatment burden in AIBD and serve as an end point in clinical trials.

Indocyanine green fluorescence imaging in the surgical management of liver cancers: current facts and future implications

Imaging detection of liver cancers and identification of the bile ducts during surgery, based on the fluorescence properties of indocyanine green, has recently been developed in liver surgery. The principle of this imaging technique relies on the intravenous administration of indocyanine green before surgery and the illumination of the surface of the liver by an infrared camera that simultaneously induces and collects the fluorescence. Detection by fluorescence is based on the contrast between the (fluorescent) tumoral or peri-tumoral tissues and the healthy (non-fluorescent) liver. Results suggest that indocyanine green fluorescence imaging is capable of identification of new liver cancers and enables the characterization of known hepatic lesions in real time during liver resection. The purpose of this paper is to present the fundamental principles of fluorescence imaging detection, to describe successively the practical and technical aspects of its use and the appearance of hepatic lesions in fluorescence, and to expose the diagnostic and therapeutic perspectives of this innovative imaging technique in liver surgery.

Analytic treatment of tipping points for social consensus in large random networks

We introduce a homogeneous pair approximation to the naming game (NG) model by deriving a six-dimensional Open Dynamics Engine (ODE) for the two-word naming game. Our ODE reveals the change in dynamical behavior of the naming game as a function of the average degree {k} of an uncorrelated network. This result is in good agreement with the numerical results. We also analyze the extended NG model that allows for presence of committed nodes and show that there is a shift of the tipping point for social consensus in sparse networks.

Outcome of extensive descending aorta repair adopting present concepts of spinal cord preservatio

AIM: Preoperative radiological identification of the Adamkiewicz artery and intraoperative neurologic monitoring are known to be helpful for preventing paraplegia after thoracoabdominal aorta replacement. To answer whether they should be used routinely, we investigated the incidence of spinal cord ischemia after extensive descending aortic repair without using such modalities. METHODS: We retrospectively reviewed the outcome of 95 patients who underwent extensive descending thoracic (DTA) or thoracoabdominal aorta (TAA) repair without the Adamkiewicz artery identification or neurologic monitoring from 2006 through 2010. Spinal cord protection strategy consisted of distal aortic perfusion, cerebrospinal fluid drainage, mild hypothermia, and maintenance of hypertension (systolic≥120mmHg) through the second postoperative day. A few segmental arteries were empirically selected for reimplantation based on the size and the amount of backbleeding; overall 1.4 per patient, 0.3 for DTA, 1.4 for type I, 2.4 for type II, 0.9 for type III, and 0 for type IV TAA. RESULTS: Two patients died early after surgery. All the remaining patients awoke without paraplegia or paraparesis. Delayed deficit occurred in 7 patients (7.4%) after hypotensive events caused by sedation, bleeding, respiratory distress, or cardiac dysfunction. Three patients (3.2%) became permanently paraplegic and the other four recovered completely within 48 hours after cerebrospinal fluid drainage and elevation of systemic blood pressure. CONCLUSION: Even without the Adamkiewicz artery identification and neuromonitoring, the incidence of immediate paraplegia could be kept low by applying the strategy based on the modern concept of cord perfusion. The relatively high incidence of delayed deficit suggests the importance of postoperative hemodynamic management and prevention of cardiopulmonary complications.