Acute Necrotizing Pancreatitis and Severe Hepatic Failure: Description of Three Cases

Introduction

Acute pancreatitis is not uncommon in fulminant hepatic failure (FHF) as confirmed by histology or serology. A few reports exist of symptomatic pancreatitis in the setting of acute viral hepatitis; the diagnosis is usually made intraoperatively or postmortem. We report three cases of liver transplant (OLT) recipients with severe acute liver failure and severe acute pancreatitis as an intraoperative finding.

Methods

We undertook a retrospective review among a large cohort of liver transplant recipients to define the impact of this problem.

Results

Between 1999 and 2007, 293. LTs were performed including 15 (5%) who had severe acute liver failure (nine with FHF and six with an emergency retransplantation [ER]). Among this group, three patients were diagnosed intraoperatively with acute necrotizing pancreatitis (ANP): two patients with associated FHF and one with an ER due to ABO incompatibility. None of the patients had symptoms of pancreatitis. In all, ANP was classified as Balthazar CT grade D-E, which determined the outcome. All the patients developed a pseudocyst and abscess, which required surgical drains.

Conclusion

ANP was diagnosed as an intraoperative finding in patients with FHF. The mechanism of pancreatitis in patients with FHF is unknown. It may be multifactorial (virus, acute liver failure, hypotension, infection, drug-induced lesion,). This association leads to a worse outcome due to the complications.     

Evaluation of Arterial Impairment after Experimental Gelatin Sponge Embolization in a Rabbit Renal Model

ObjectiveArterial stenosis is a major obstacle for subsequent interventional procedures. We hypothesized that the stenosis is caused by gelatin sponge embolization and performed an experimental study in a rabbit renal model.ResultsGelatin sponge particles were mainly observed in the segmental and interlobar arteries. Transmural inflammation of the embolized arterial wall and mild thickening of the media were observed 1 week after embolization. Resorption of the gelatin sponge and organization of thrombus accompanied by foreign body reactions, were observed from 2 to 4 weeks after embolization. Microscopic images of the 3 weeks group showed vessel lumens filled mostly with organized thrombi, resulting in severe stenosis. Additionally, vessels showed a thickened intima that contained migrating smooth muscle cells and accompanying interruption of the internal elastic lamina. The migrating smooth muscle cells were distributed around the recanalized arterial lumen.ConclusionGelatin sponge embolization may induce arterial stenosis by causing organized thrombus and intimal hyperplasia, which consists of migrating smooth muscle cells and intimal collagen deposits.     

Detection of the center of the hip joint in computer-assisted surgery: an evaluation study of the Surgetics algorithm.

OBJECTIVE: The aim of this paper is to assess the accuracy of an algorithm implemented by PRAXIM in the SURGETICS navigation station for detection of the hip center. This study will assess the robustness and accuracy of the algorithm in various clinical situations such as those involving non-sphericity of the femoral head, motion of the pelvis during hip center detection, and restricted range of motion. MATERIALS AND METHODS: The localization of the hip center, based on kinematics, relies on the recording of n successive positions of the femoral rigid body in the localizer reference system during a passive circumduction motion of the hip joint. Therefore, the shape of the clouds of points acquired may vary from one acquisition to the next. To allow a comprehensive study of the consequences of these variations for hip center detection, we developed a simulator to generate numerous clouds of points. Results given subsequently for each test are the values of the difference between the femoral mechanical axis computed with C(c), the computed hip center, and the same axis computed with C(o), the reference hip center. RESULTS: Test 1: Sensitivity to noise. The errors ranged from 3.33 E - 12 (SD 3.29E - 12) for a noise of 0 mm to 8.18E - 1 (SD - 7.05E - 1) for a noise of 15 mm. Test 2: Sensitivity to the shape of the acquisition motion. All trajectories gave an error < 1 degrees . Test 3: Sensitivity to restricted range of motion. No value > 1 degrees was found during this test. Test 4: Sensitivity to the distance between two points of the cloud. No value > 0.5 degrees was found during this test. Test 5: Sensitivity to the number of points included in the cloud. No value > 1 degrees was found during this test. CONCLUSIONS: The Surgetics algorithm is robust to noise, can compensate for pelvic motion, and can be used even in the case of restricted range of motion.     

Mitochondrial Networking Protects ��-Cells From Nutrient-Induced Apoptosis

OBJECTIVE

Previous studies have reported that β-cell mitochondria exist as discrete organelles that exhibit heterogeneous bioenergetic capacity. To date, networking activity, and its role in mediating β-cell mitochondrial morphology and function, remains unclear. In this article, we investigate β-cell mitochondrial fusion and fission in detail and report alterations in response to various combinations of nutrients.

RESEARCH DESIGN AND METHODS

Using matrix-targeted photoactivatable green fluorescent protein, mitochondria were tagged and tracked in β-cells within intact islets, as isolated cells and as cell lines, revealing frequent fusion and fission events. Manipulations of key mitochondrial dynamics proteins OPA1, DRP1, and Fis1 were tested for their role in β-cell mitochondrial morphology. The combined effects of free fatty acid and glucose on β-cell survival, function, and mitochondrial morphology were explored with relation to alterations in fusion and fission capacity.

RESULTS

β-Cell mitochondria are constantly involved in fusion and fission activity that underlies the overall morphology of the organelle. We find that networking activity among mitochondria is capable of distributing a localized green fluorescent protein signal throughout an isolated β-cell, a β-cell within an islet, and an INS1 cell. Under noxious conditions, we find that β-cell mitochondria become fragmented and lose their ability to undergo fusion. Interestingly, manipulations that shift the dynamic balance to favor fusion are able to prevent mitochondrial fragmentation, maintain mitochondrial dynamics, and prevent apoptosis.

CONCLUSIONS

These data suggest that alterations in mitochondrial fusion and fission play a critical role in nutrient-induced β-cell apoptosis and may be involved in the pathophysiology of type 2 diabetes.Mitochondria mediate β-cell responses to extracellular glucose by generating ATP and initiating a cascade of events culminating in the release of insulin. It is not surprising that β-cell mitochondria have become an important target for investigations into the etiology of type 2 diabetes. Mitochondria are highly dynamic organelles whose morphology is regulated by cycles of fusion and fission, collectively termed mitochondrial dynamics (1,2). Networks are formed when mitochondria undergo fusion events that cause the compartments of participating mitochondria to become continuous. As a result, the constituents of each network share solutes, metabolites, and proteins (3–5) as well as a transmembrane electrochemical gradient (1,6). The disruption of such networks has been shown to have a profound effect on the progression of cells to apoptosis, particularly in cases where reactive oxygen species (ROS) are involved (7). As such, mitochondrial networking is thought to be a potential defense mechanism allowing for the buffering of mitochondrial ROS and calcium overload (8,9).Chronically elevated levels of glucose and fatty acid are thought to contribute to the progression of type 2 diabetes by adversely affecting β-cells and thereby causing a deterioration in insulin secretion (10). In vivo, a reduction in insulin gene expression due to reduced Pdx-1 binding has been observed in rats perifused with glucose and intralipids (11,12). In addition, exposure to high levels of glucose and/or free fatty acid has been shown to affect β-cell viability by inducing mitochondrial apoptosis and has been linked to ROS-induced mitochondrial calcium overload and damage (13). Recent studies indicate that nutrient-induced ROS increases subcellular mitochondrial membrane potential (ΔΨmt) heterogeneity and fragmentation of the mitochondrial architecture (14,15). These findings suggest that mitochondrial fragmentation-defragmentation might play a role in the effects of noxious stimuli. Although the functional significance of these changes has not been studied in β-cells, studies of mitochondrial morphology in other cells have demonstrated that the ability of mitochondria to form networks influences both ROS and calcium handling (7–9).Previous studies have reported that β-cell mitochondria form less elaborate network structures, compared with COS cells for example, and raise doubts on the existence of mitochondrial networking in these cells. Until now, technologies for examining and quantifying the ability of mitochondria to undergo fusion and fission were unavailable.In this work, we show that the densely packed appearance of mitochondria in the β-cell represents the existence of multiple juxtaposed units that do not share continuous matrix lumen but do go through frequent fusion and fission events. We further demonstrate that mitochondrial dynamics are disrupted by exposure to the combination of high fat and glucose, gradually leading to the arrest of fusion activity and complete fragmentation of the mitochondrial architecture. Inhibiting mitochondrial fission preserved mitochondrial morphology and dynamics and prevented β-cell apoptosis.     

Effect of Balloon‐Expandable Transcatheter Aortic Valve Replacement Positioning: A Patient‐Specific Numerical Model

Transcatheter aortic valve replacement (TAVR) has emerged as a life‐saving and effective alternative to surgical valve replacement in high‐risk, elderly patients with severe calcific aortic stenosis. Despite its early promise, certain limitations and adverse events, such as suboptimal placement and valve migration, have been reported. In the present study, it was aimed to evaluate the effect of various TAVR deployment locations on the procedural outcome by assessing the risk for valve migration. The deployment of a balloon‐expandable Edwards SAPIEN valve was simulated via finite element analysis in a patient‐specific calcified aortic root, which was reconstructed from CT scans of a retrospective case of valve migration. The deployment location was parametrized in three configurations and the anchorage was quantitatively assessed based on the contact between the stent and the native valve during the deployment and recoil phases. The proximal deployment led to lower contact area between the native leaflets and the stent which poses higher risk for valve migration. The distal and midway positions resulted in comparable outcomes, with the former providing a slightly better anchorage. The approach presented might be used as a predictive tool for procedural planning in order to prevent prosthesis migration and achieve better clinical outcomes.     

Patient‐Specific Orthopaedic Implants

Patient‐specific orthopaedic implants are emerging as a clinically promising treatment option for a growing number of conditions to better match an individual's anatomy. Patient‐specific implant (PSI) technology aims to reduce overall procedural costs, minimize surgical time, and maximize patient outcomes by achieving better biomechanical implant fit. With this commercially‐available technology, computed tomography or magnetic resonance images can be used in conjunction with specialized computer programs to create preoperative patient‐specific surgical plans and to develop custom cutting guides from 3‐D reconstructed images of patient anatomy. Surgeons can then place these temporary guides or “jigs” during the procedure, allowing them to better recreate the exact resections of the computer‐generated surgical plan. Over the past decade, patient‐specific implants have seen increased use in orthopaedics and they have been widely indicated in total knee arthroplasty, total hip arthroplasty, and corrective osteotomies. Patient‐specific implants have also been explored for use in total shoulder arthroplasty and spinal surgery. Despite their increasing popularity, significant support for PSI use in orthopaedics has been lacking in the literature and it is currently uncertain whether the theoretical biomechanical advantages of patient‐specific orthopaedic implants carry true advantages in surgical outcomes when compared to standard procedures. The purpose of this review was to assess the current status of patient‐specific orthopaedic implants, to explore their future direction, and to summarize any comparative published studies that measure definitive surgical characteristics of patient‐specific orthopaedic implant use such as patient outcomes, biomechanical implant alignment, surgical cost, patient blood loss, or patient recovery.     

Reconstruction of a transmetatarsal amputation stump using a salvaged peroneal artery fasciocutaneous flap from the opposite leg: A case report

During lower extremity amputation, the objective is to provide a functional residual limb that permits maximum patient mobility and independence. Preservation of length of the fore part of the foot using salvageable tissue from the amputated part in young patients prevents equines deformity and revision of amputation to a higher level. This can be achieved using tissue available from the amputated part. The spare part concept in reconstructive surgery should be integrated into the trauma algorithm to avoid additional donor site morbidity. Reported here is a young adult patient with crush injuries to both feet, which resulted in amputations. A fasciocutaneous flap raised from one extremity was used to facilitate transmetatarsal amputation stump length preservation of the other extremity.     

A comparative study of the renal damage produced after the extracorporeal shock wave lithotripsy according to the lithiasis location

IntroductionThe Extracorporeal shock waves lithotripsy (ESWL) is fundamental in the treatment of lithiasis. However, there are evidences that it can produce renal damage. The objective of our study is to determine the degree of affectation of the glomerular and tubular function after LEOC, and the influence of the lithiasis location on the type of renal damage.Material and methodsA prospective longitudinal study was carried out in 14 patients with normal renal function subjected to ESWL. We determined the basal level, and the levels at the 24 hours, at the 4th and the 10th day post ESWL of: microalbuminuria (MA) (that values the glomerular function), and N-acetil glucosamide (NAG) and alanine aminopeptidase (AAP), (that value the tubular function).ResultsThe basal levels of of MA, NAG and AAP didn’t show significant differences in connection with the localization of the stones. A significant increase was observed of the three parameters only 24 hours post ESWL No significant differences were observed between the variation of the microalbuminuria levels, AAP and NAG and the treatment in relation to the localization of the stones.ConclusionsIt exists a glomerular and tubular damage after ESWL. This damage is not related with the pelvic or calicial location of the stones. In patient with previous normal renal function, the renal damage recovers at the 4º day post ESWL.