Abdominal aortic aneurysm volume and relative intraluminal thrombus volume might be auxiliary predictors of rupture-an observational cross-sectional study

Objectives

The study aimed to identify differences and compare anatomical and biomechanical features between elective and ruptured abdominal aortic aneurysms (AAAs).

Methods

Data (clinical, anatomical, and biomechanical) of 98 patients with AAA, 75 (76.53%) asymptomatic (Group aAAA) and 23 (23.46%) ruptured AAA (Group rAAA), were prospectively collected and analyzed. Anatomical, morphological, and biomechanical imaging markers like peak wall stress (PWS) and rupture risk equivalent diameter (RRED), comorbid conditions, and demographics were compared between the groups. Biomechanical features were assessed by analysis of Digital Imaging and Communication in Medicine images by A4clinics (Vascops), and anatomical features were assessed by 3Surgery (Trimensio). Binary and multiple logistic regression analysis were used and adjusted for confounders. Accuracy was assessed using receiving operative characteristic (ROC) curve analysis.

Results

In a multivariable model, including gender and age as confounder variables, maximal aneurysm diameter [MAD, odds ratio (OR) = 1.063], relative intraluminal thrombus (rILT, OR = 1.039), and total aneurysm volume (TAV, OR = 1.006) continued to be significant predictors of AAA rupture with PWS (OR = 1.010) and RRED (OR = 1.031). Area under the ROC curve values and correct classification (cc) for the same parameters and the model that combines MAD, TAV, and rILT were measured: MAD (0.790, cc = 75%), PWS (0.713, cc = 73%), RRED (0.717, cc = 55%), TAV (0.756, cc = 79%), rILT (0.656, cc = 60%), and MAD + TAV + rILT (0.797, cc = 82%).

Conclusion

Based on our results, in addition to MAD, other important predictors of rupture that might be used during aneurysm surveillance are TAV and rILT. Biomechanical parameters (PWS, RRED) as valuable predictors should be assessed in prospective clinical trials. Similar studies on AAA smaller than 55 mm in diameter, even difficult to organize, would be of even greater clinical value.

Kidney injury secondary to endovascular treatment of renal artery stenosis

In this paper, we present a case of kidney injury as a complication of renal artery angioplasty in a 54-year-old female patient that suffered from resistant renovascular hypertension. This case emphasises the unpredictable nature of endovascular procedures, the need for careful post-procedure evaluation and the role of 'old fashioned' surgical techniques in resolving complications of endovascular procedures.

Differences between immediate and late onset of spinal cord ischemia after open and endovascular aortic interventions

Spinal cord ischemia remains the most impressive and colliding complication following open surgical and endovascular aortic procedures. Paraparesis and paraplegia are devastating, having a major invalidating impact on the patient's life. Also for the surgeon and the entire team this dramatic adverse event causes a significant concussion. Surgeons faced this problem in practice in the 1950s when this surgery started being applied. Even A. Carrel in 1910 said, "The main danger of the aortic operation does not come from the heart or from the aorta itself, but from the central nervous system". As the number of these surgeries grew, some were followed by the spinal cord ischemia. Now, in 21st century, problem of spinal cord ischemia still exists. By understanding the reasons of its development we shall be able to find more useful methods for prevention as well as for the treatment. The aim of this article was to search what is behind this dreadful complication, explaining different mechanisms which take part in its development during endovascular and open surgical treatment.

Spinal cord ischemia after aortic surgery

This article discusses the etiology of spinal cord ischemia (SCI) mechanisms that may lead to paraplegia during open and endovascular repair from an anatomical and physiological perspective as well as the role of various protective measures used in prevention of this dreadful complication of aortic surgery. There are many adjuncts that must be considered to reduce the risk of spinal cord injury, such as revascularisation of intercostal arteries, maintenance of high mean blood pressure, spinal cord drainage and a few new promising models like NIRS and MISACE which usefulness is yet to be determined. These measures and techniques as well as possible etiology mechanisms of SCI are discussed, highlighting the evidence available for each method, the practical ways in which they may be used, giving some new theories and explanations.

Treatment strategy for ruptured abdominal aortic aneurysms

Rupture is the most serious and lethal complication of the abdominal aortic aneurysm. Despite all improvements during the past 50 years, ruptured abdominal aortic aneurysms are still associated with very high mortality. Namely, including patients who die before reaching the hospital, the mortality rate due to abdominal aortic aneurysm rupture is 90%. On the other hand, during the last twenty years, the number of abdominal aortic aneurysms significantly increased. One of the reasons is the fact that in majority of countries the general population is older nowadays. Due to this, the number of degenerative AAA is increasing. This is also the case for patients with abdominal aortic aneurysm rupture. Age must not be the reason of a treatment refusal. Optimal therapeutic option ought to be found. The following article is based on literature analysis including current guidelines but also on my Clinics significant experience. Furthermore, this article show cases options for vascular medicine in undeveloped countries that can not apply endovascular procedures at a sufficient level and to a sufficient extent. At this moment the following is evident. Thirty-day-mortality after repair of ruptured abdominal aortic aneurysms is significantly lower in high-volume hospitals. Due to different reasons all ruptured abdominal aortic aneurysms are not suitable for EVAR. Open repair of ruptured abdominal aortic aneurysm should be performed by experienced open vascular surgeons. This could also be said for the treatment of endovascular complications that require open surgical conversion. There is no ideal procedure for the treatment of AAA. Each has its own advantages and disadvantages, its own limits and complications, as well as indications and contraindications. Future reductions in mortality of ruptured abdominal aortic aneurysms will depend on implementation of population-based screening; on strategies to prevent postoperative organ injury and also on new medical technology improvements. Taking this into consideration, education of young vascular surgeons in endovascular but also in open aortic surgery, is of vast importance.

Posterior approach for sciatic aneurysm repair - technical note

Aneurysm of the persistent sciatic artery is a rare cause of limb ischemia, which is a challenge for both diagnosis and treatment. After successful diagnosis adequate treatment may require skills in open and endovascular surgery. We present a patient with the aneurysm of the persistent sciatic artery treated by bypass procedure with PTFE graft using posterior approach. We named this procedure "dorsal bypass". Detailed explanation of clinical presentation, diagnosis and the surgical procedure is given in this paper.

Dacron or ePTFE graft for above-knee femoropopliteal bypass reconstruction. A bi-centre randomised study

BACKGROUND

The objective of this study was to compare polyester (Dacron) and expanded polytetrafluorethilene (ePTFE) grafts for above-knee femoropopliteal bypass.

PATIENTS AND METHODS

Eighty five patients with disabling claudications or limb threatening ischemia suitable for above-knee femoropopliteal reconstruction were randomized into two groups. In the first group the surgery was performed using 8 mm Dacron graft, whereas the patients in the second group were operated using ePTFE grafts.

RESULTS

The primary patency rates for Dacron and ePTFE were 100 %, and 88.37 % (p < 0.05), while secondary patency rates were 83.3 % and 75 % (p > 0.05) respectively. The early limb salvage rates for Dacron and ePTFE were 100 % and 97.7 % (p > 0.05). Early (30-day) complications (bleeding 2.38 % and 2.32 %; wound infection 11.9 % and 11.63 %) occurred in both groups with similar frequency (p > 0.05). The patients were followed up over a period of 6 to 12 months (mean 8.3 +/- 3.6 months). The overall mortality rate in the follow-up period was 2.38 % (one patient) for Dacron and 6.98 % (three patients) for ePTFE group (p > 0.05). Late graft infection was noted in three patients (7.1 %) in Dacron, and two patients (4.65 %) in ePTFE group (p > 0.05). Primary patency rates were not significantly influenced by obesity, diabetes, hypertension, hyperlipidemia, cigarette smoking, (p > 0.05). However, poor run-off (only one crural artery patent on preoperative angiography) significantly decreased patency of both grafts and favored the use of ePTFE graft (p < 0.05).

CONCLUSIONS

This study confirms that both materials are suitable for above-knee femoropopliteal reconstructions. Above-knee femoropopliteal bypass does not have a good long-term prognosis in the presence of poor run-off.

Aneurysm of the inferior vena cava: case report and review of the literature

Aneurysms of the inferior vena cava (IVC) are extremely rare. To the best of our knowledge, only 29 cases of IVC aneurysms are published in literature. We present a new case of surgically treated symptomatic saccular aneurysm of the infrarenal IVC and review previously published cases. Following resection of the aneurysm and the thrombosed infrarenal IVC, the patient fully recovered. Thrombosed IVC aneurysm may mimic a retroperitoneal tumour. In some cases, CT and MRI findings may be equivocal. Surgical treatment is indicated in all symptomatic and low-risk asymptomatic cases.

Alteration of expression of muscle specific isoforms of the fragile X related protein 1 (FXR1P) in facioscapulohumeral muscular dystrophy patients

BACKGROUND

The Fragile X Mental retardation-Related 1 (FXR1) gene belongs to the fragile X related family, that also includes the Fragile X Mental Retardation (FMR1) gene involved in fragile X syndrome, the most common form of inherited mental retardation. While the absence of FMRP impairs cognitive functions, inactivation of FXR1 has been reported to have drastic effects in mouse and xenopus myogenesis. Seven alternatively spliced FXR1 mRNA variants have been identified, three of them being muscle specific. Interestingly, they encode FXR1P isoforms displaying selective RNA binding properties.

METHODS AND RESULTS

Since facioscapulohumeral muscular dystrophy (FSHD) is an inherited myopathy characterised by altered splicing of mRNAs encoding muscle specific proteins, we have studied the splicing pattern of FXR1 mRNA in myoblasts and myotubes of FSHD patients. We show here that FSHD myoblasts display an abnormal pattern of expression of FXR1P isoforms. Moreover, we provide evidence that this altered pattern of expression is due to a specific reduced stability of muscle specific FXR1 mRNA variants, leading to a reduced expression of FXR1P muscle specific isoforms.

CONCLUSION

Our data suggest that the molecular basis of FSHD not only involves splicing alterations, as previously proposed, but may also involve a deregulation of mRNA stability. In addition, since FXR1P is an RNA binding protein likely to regulate the metabolism of muscle specific mRNAs during myogenesis, its altered expression in FSHD myoblasts may contribute to the physiopathology of this disease.

Takayasu's aortoarteritis

Surgical treatment of two female patients aged 32 and 41 years, with neurological problems causes by type I Takayasu's aortoarteritis, are presented here. Both of them were treated with by pass from ascending aorta to left common carotid and left subclavian arteries, using transsternal approach. During the follow up period (3.5 years for the first, and 2 years for the second patient) both patients were free of neurologic symptoms. Corticosteroid therapy was given to the first patient for controlling of active diseases, immediatelly after the operation and during the first three postoperative months. By this reason an infection af the proximal part of sternal wound was developed. MRI showed involvement of the vascular graft. Due to high risk of reoperation, medical treatment was performed. Takayasu's aortoarteritis is very unsommon in our country, as well as in other countries which don't belong to Far East. In cases with hemodinamic important arterial lesions produced disabling symptoms, a standard PTA and reconstructive vascular procedures are indicated. Takayasu's aortoarteritis is a complex disease. It requires combined dignostic and therapeutic approaches which produce satisffied long-term results.

Disordered RNA chaperone proteins: from functions to disease

RNA chaperones are ubiquitous proteins that play pivotal roles in cellular RNA metabolism and RNA virus replication. Here we propose that they act by organizing complex and highly dynamic networks of RNA-RNA, RNA-protein and protein-protein interactions. How this is achieved and how their malfunction may lead to disease will be discussed through the examples of human immunodeficiency virus type 1 nucleocapsid protein (NCp7), the fragile X mental retardation protein and the prion protein.

Importance of poly(ADP-ribose) glycohydrolase in the control of poly(ADP-ribose) metabolism

Poly(ADP-ribosyl)ation is a posttranslational modification that alters the functions of the acceptor proteins and is catalyzed by the poly(ADP-ribose) polymerase (PARP) family of enzymes. Following DNA damage, activated poly(ADP-ribose) polymerase-1 (PARP-1) catalyzes the elongation and branching of poly(ADP-ribose) (pADPr) covalently attached to nuclear target proteins. Although the biological role of poly(ADP-ribosyl)ation has not yet been defined, it has been implicated in many important cellular processes such as DNA repair and replication, modulation of chromatin structure, and apoptosis. The transient nature and modulation of poly(ADP-ribosyl)ation depend on the activity of a unique cytoplasmic enzyme called poly(ADP-ribose) glycohydrolase which hydrolyzes pADPr bound to acceptor proteins in free ADP-ribose residues. While the PARP homologues have been recently reviewed, there are relatively scarce data about PARG in the literature. Here we summarize the latest advances in the PARG field, addressing the question of its putative nucleo-cytoplasmic shuttling that could enable the tight regulation of pADPr metabolism. This would contribute to the elucidation of the biological significance of poly(ADP-ribosyl)ation.

Post-traumatic AV fistulas and pseudoaneurysms

METHODS

The authors present the surgical treatment of 20 post-traumatic arteriovenous fistulas and 33 arterial pseudoaneurysms that have been treated in the last 5 years in the Centre for Vascular Surgery of the Institute for Cardiovascular Diseases, Clinical Centre of Serbia in Belgrade. Five women and 45 men (mean age 31.7 years) were examined. There were 28 war and 22 non-combatant injuries. In most cases superficial femoral artery and vein were involved. The average time elapsed from the moment of injury until the operation started, was 9 months in patients with AV fistulas, and one month for patients with pseudoaneurysms.

RESULTS

In all of the patients with AV fistulas, arterial and venous reconstructions were performed, except in 4 cases where the veins were ligated. Surgical reconstruction was performed in 26 patients with pseudoaneurysms, while in 7 cases the artery was ligated. There were no cases of postoperative ischemia in patients due to arterial ligation. Patients were followed for 2 years and 2 months postoperatively. As far as the reconstructive operations are concerned, the postoperative patency rate was 100%, while limb salvage was achieved in 96.9%. Namely, one amputation was done in spite of high arterial patency rate, which was indicated by massive bone-muscle tissue loss, occurring during mine explosive injury.

CONCLUSIONS

Because of the rapid disease progress, the authors suggest that the operative treatment of post-traumatic AV fistulas and pseudoaneurysms should be performed as soon as possible. This was supported by good follow-up results in operatively treated patients.

Involvement of the central nervous system in the general response to pulmonary blast injury

The local, general, and cerebral responses of rabbits exposed to pulmonary blasts were examined to define the role of vagal afferentation in cardiorespiratory as well as metabolic control after a blast injury. Two series of experiments were conducted on rabbits to analyze the general, local, and cerebral responses to pulmonary injury caused by blast overpressure, and to evaluate the effects of bilateral vagotomy on the general, local, and cerebral responses to local (pulmonary) blast injury. The blast wave was generated in laboratory conditions using an air-driven shock tube that was able to cause moderate pulmonary blast injury, i.e., four pulmonary contusions characterized as confluent ecchymoses involving 30 to 60% of the lungs. One group of animals was subjected to pulmonary deafferentation, performed by bilateral transections of the vagus, glossopharyngeal, and hypoglossal nerves. Numerous hemodynamic as well as biochemical parameters were observed in systemic circulation and in lung and brain (medulla oblongata) tissues. After observation during the early posttraumatic period, rabbits were sacrificed by decapitation 30 minutes after the blast injury. On the basis of obtained results, it was concluded that vagal afferents have an important role in the modification of general and local responses to a pulmonary blast injury. Furthermore, it was suggested that functional changes in medulla oblongata may be the consequences of afferent neural impulses from the injured region (lungs) rather than consequences of ischemia, energy transfer to the brain, or both.