Efferent Branches Research Articles

Neuroimmune Cross Talk in the Gut. Neuroendocrine and neuroimmune pathways contribute to the pathophysiology of irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a common disorder characterized by recurrent abdominal pain, bloating, and disturbed bowel habit, symptoms that impact the quality of life of sufferers. The pathophysiological changes underlying this multifactorial condition are complex and include increased sensitivity to luminal and mucosal factors, resulting in altered colonic transit and visceral pain. Moreover, dysfunctional communication in the bidirectional signaling axis between the brain and the gut, which involves efferent and afferent branches of the peripheral nervous system, circulating endocrine hormones, and local paracrine and neurocrine factors, including immune and perhaps even microbial signaling molecules, has a role to play in this disorder. This minireview will examine recent advances in our understanding of the pathophysiology of IBS and assess how cross talk between hormones, immune, and microbe-derived factors and their neuromodulatory effects on peripheral nerves may underlie IBS symptomatology.

Bases anatomiques et principe du nerve-sparing au cours de l’hystérectomie radicale pour cancer du col utérin

Radical hysterectomy (RH) is an effective treatment for early-stage cervical cancer IA2 to IIA1 but RH is often associated with several significant complications such as urinary, anorectal and sexual dysfunction due to pelvic nerve injuries. Pelvic autonomic nerves including the superior hypogastric plexus (SHP), hypogastric nerves (HN), pelvic splanchnic nerves (PSN), sacral splanchnic nerves (SSN), inferior hypogastric plexus (IHP) and efferent branches of the IHP. We aimed to precise the neuroanatomy of the female pelvis in order to provide key-points of surgical anatomy to improve NSRH for cervical cancer. The SHP could be injured during periaortic lymph node dissection and its preservation necessitates an approach on the right side of the aorta and a blunt dissection of the promontory before lomboaortic lymphadenectomy. Injuries to HN can occur during the resection of USL at the posterior pelvic wall and of rectovaginal ligaments and to preserve HN only the medial fibrous part of the uterosacral ligament should be resected. The middle rectal artery, the deep uterine vein and the ureter should be identified to preserve PSN and IHP during resection of paracervix. Vesical branches can be preserved by blunt dissection of the posterior layer of the vesicouterine ligament after identifying the inferior vesical vein. In most of cases, NSRH for cervical cancer can be performed. Anatomical landmarks as middle rectal artery, deep uterine vein, inferior vesical vein and ureter and the respect of nervous part of uterine ligament and of parametrium provide to surgeon a safe preservation of pelvic innervation without compromising oncological outcomes.

Commentary on ‘Selective AAA sac Embolization During EVAR to Prevent Type II Endoleaks’

In this edition of the European Journal of Vascular and Endovascular Surgery, Mascoli and co-workers present their interesting strategy for embolization of the abdominal aortic aneurysm (AAA) sac during primary endovascular aortic repair (EVAR) in patients deemed at high risk of type II endoleaks. High risk is defined as at least six patent efferent AAA side branches and/or anAAA thrombus volume ratio<40%. During short-term follow up with standard (0 and 6 months) or contrast enhanced (12 months) ultrasound, the number of persistent type II endoleaks was significantly lower in a group of 26 embolized patients compared with 44 morphologically matched controls. Is this an inventive example of locking the stable door before the horse has bolted or do the authors see potential problems, which do not exist? Three major issues should be discussed: Is there any need to treat type II endoleaks at all? Is the suggested coiling technique efficient? Are there any, and maybe better, endovascular alternatives? To date there is no optimal threshold for the intervention of isolated type II endoleaks post-EVAR. In a recently published systematic review and meta-regression of 231 patients, the treatment of type II endoleaks did not lead to a reduced sac expansion rate or improved sac regression rate compared with conservative management. This is in line with the 1 year results of the current study. Moreover, no post-EVAR ruptures occurred.These benign outcomes of type II endoleaks have been duplicated by other researchers recently, with an incidence of <1% of post-EVAR ruptures in patients with persistent type II endoleak. Interestingly, Nolz and co-workers showed an association between type II endoleak and decreased surface movements of the proximal anchoring zones and distal limbs of endografts, which may lead to a more stable endograft position. The advancement of several coils into the aneurysm sac led to a disappointing 69% success rate at the pre-discharge duplex ultrasound. Although Mascoli and colleagues used bony landmarks of the pre-EVAR computed tomograms (CT), their embolization technique sometimes must have been a shot in the dark. It seems more reasonable to use a targeted

Hypothetical Link Between Osteopathic Suboccipital Decompression and Neuroimmunomodulation

Emerging evidence has begun to depict the molecular mechanisms by which inflammation is regulated via the vagus nerve. Specifically, inflammation can be controlled by neuroimmunologic circuitry, dependent upon vagal afferent and efferent fibers, operating in a reflexive continuum. This neuro-immune reflex, known as the inflammatory reflex arc, has some control on serum concentrations of numerous molecular mediators of inflammation such as C-reactive protein and interleukin-6. Importantly, both of these inflammatory proteins are elevated in acute ST-elevation myocardial infarction and are associated with worse cardiac sequelae. Suboccipital decompression by osteopathic manual treatment has been demonstrated to enhance vagal output to the heart, as measured by increased high frequency spectral power of heart rate variability, in a statistically significant manner further supported by a significant decrease in the low-/high frequency spectral power ratio among healthy adults compared to sham treatment and time control. Considering this association, we postulate that suboccipital decompression may stimulate the efferent branch of this vagal-mediated reflex, the cholinergic antiinflammatory pathway, thereby suppressing C-reactive protein and interleukin-6 levels post-ST-elevation myocardial infarction. Furthermore, we provide a detailed clinical study that can determine the validity of our hypothesis.

Intracranial-to-intracranial bypass for posterior inferior cerebellar artery aneurysms: options, technical challenges, and results in 35 patients.

OBJECT Intracranial-to-intracranial (IC-IC) bypasses are alternatives to traditional extracranial-to-intracranial (EC-IC) bypasses to reanastomose parent arteries, reimplant efferent branches, revascularize branches with in situ donor arteries, and reconstruct bifurcations with interposition grafts that are entirely intracranial. These bypasses represent an evolution in bypass surgery from using scalp arteries and remote donor sites toward a more local and reconstructive approach. IC-IC bypass can be utilized preferentially when revascularization is needed in the management of complex aneurysms. Experiences using IC-IC bypass, as applied to posterior inferior cerebellar artery (PICA) aneurysms in 35 patients, were reviewed. METHODS Patients with PICA aneurysms and vertebral artery (VA) aneurysms involving the PICA's origin were identified from a prospectively maintained database of the Vascular Neurosurgery Service, and patients who underwent bypass procedures for PICA revascularization were included. RESULTS During a 17-year period in which 129 PICA aneurysms in 125 patients were treated microsurgically, 35 IC-IC bypasses were performed as part of PICA aneurysm management, including in situ p3-p3 PICA-PICA bypass in 11 patients (31%), PICA reimplantation in 9 patients (26%), reanastomosis in 14 patients (40%), and 1 V3 VA-to-PICA bypass with an interposition graft (3%). All aneurysms were completely or nearly completely obliterated, 94% of bypasses were patent, 77% of patients were improved or unchanged after treatment, and good outcomes (modified Rankin Scale ≤ 2) were observed in 76% of patients. Two patients died expectantly. Ischemic complications were limited to 2 patients in whom the bypasses occluded, and permanent lower cranial nerve morbidity was limited to 3 patients and did not compromise independent function in any of the patients. CONCLUSIONS PICA aneurysms receive the application of IC-IC bypass better than any other aneurysm, with nearly one-quarter of all PICA aneurysms treated microsurgically at our center requiring bypass without a single EC-IC bypass. The selection of PICA bypass is almost algorithmic: trapped aneurysms at the PICA origin or p1 segment are revascularized with a PICA-PICA bypass, with PICA reimplantation as an alternative; trapped p2 segment aneurysms are reanastomosed, bypassed in situ, or reimplanted; distal p3 segment aneurysms are reanastomosed or revascularized with a PICA-PICA bypass; and aneurysms of the p4 segment that are too distal for PICA-PICA bypass are reanastomosed. Interposition grafts are reserved for when these 3 primary options are unsuitable. A constructive approach that preserves the PICA with direct clipping or replaces flow with a bypass when sacrificed should remain an alternative to deconstructive PICA occlusion and endovascular coiling when complete aneurysm occlusion is unlikely.

Aberrant facial flushing following monobloc fronto-facial distraction.

Patients with syndromic forms of craniosynostosis may experience functional problems such as raised intracranial pressure, proptosis, obstructive sleep apnoea and failure to thrive. The monobloc fronto-facial advancement with osteogenic distraction is increasingly used to correct these functional problems in one procedure as well as improve appearance. The authors report the phenomenon of post operative aberrant facial flushing - an unusual and previously unreported complication of the procedure. The case notes of 80 consecutive patients undergoing fronto-facial advancement by distraction using the rigid external distraction device (RED) were reviewed for features of aberrant facial flushing. Four out of eighty individuals developed facial flushing after monobloc fronto-facial distraction using the rigid external distractor (RED) frame. All were female with Crouzon or Pfeiffer syndromes causing the severe functional problems for which they underwent the surgery. They were aged 6-8 years. Following removal of the frame, they developed intermittent but severe facial flushing. The flushing spontaneously settled in three patients after up to four years but persists in the other child seven years after her surgery. Aberrant facial flushing is a rare but significant complication of monobloc fronto-facial surgery. It occurred in 4 of our 80 (5%) patients. The skull base osteotomies essential for the procedure are made anterior to the pterygopalatine ganglion and it is our contention that damage from these was responsible for a neuropraxia of its efferent nerve branches. A review of the autonomic control of the facial vascular system suggests that the phenomenon is due to an unequal process of recovery that leaves the cutaneous vasodilating parasympathetic or beta-adrenergic innervation relatively unopposed - a situation that persists until with time a normal balance of autonomic input is achieved.

Endovascular Treatment of Middle Cerebral Artery Aneurysm with the LVIS Junior Stent

Middle cerebral artery (MCA) aneurysms often occur in small parent vessels and are incorporated with the orifice of acute-angled efferent branch vessels. Endovascular treatment for these aneurysms remains technically challenging. This study aimed to assess the clinical safety and efficacy of the Low-profile Visualized Intraluminal Support Junior (LVIS Jr) stent for embolization of MCA aneurysms. Eighteen intracranial aneurysms, including 13 unruptured and 5 ruptured aneurysms, were treated with LVIS Jr stent-assisted coil embolization. The clinical data and technical results are presented. A total of 18 stents were successfully delivered to the target aneurysms, and the technical success rate was 100%. There was complete occlusion in 8 (44.4%) of 18 cases, neck remnants in 7 (38.9%) cases, and partial occlusion in 3 (16.7%) cases. In-stent thrombosis occurred in 1 case, and the symptoms disappeared after transvenous tirofiban injection. The modified Rankin Scale score at discharge was 0 in 14 patients, 1 in 3 patients, and 2 in 1 patient. The LVIS Jr stent provided excellent trackability and deliverability and is safe and effective for the treatment of wide-necked MCA aneurysms with tortuous and smaller parent vessels.

Increased Efferent Cardiac Sympathetic Nerve Activity and Defective Intrinsic Heart Rate Regulation in Type 2 Diabetes.

Elevated sympathetic nerve activity (SNA) coupled with dysregulated β-adrenoceptor (β-AR) signaling is postulated as a major driving force for cardiac dysfunction in patients with type 2 diabetes; however, cardiac SNA has never been assessed directly in diabetes. Our aim was to measure the sympathetic input to and the β-AR responsiveness of the heart in the type 2 diabetic heart. In vivo recording of SNA of the left efferent cardiac sympathetic branch of the stellate ganglion in Zucker diabetic fatty rats revealed an elevated resting cardiac SNA and doubled firing rate compared with nondiabetic rats. Ex vivo, in isolated denervated hearts, the intrinsic heart rate was markedly reduced. Contractile and relaxation responses to β-AR stimulation with dobutamine were compromised in externally paced diabetic hearts, but not in diabetic hearts allowed to regulate their own heart rate. Protein levels of left ventricular β1-AR and Gs (guanine nucleotide binding protein stimulatory) were reduced, whereas left ventricular and right atrial β2-AR and Gi (guanine nucleotide binding protein inhibitory regulatory) levels were increased. The elevated resting cardiac SNA in type 2 diabetes, combined with the reduced cardiac β-AR responsiveness, suggests that the maintenance of normal cardiovascular function requires elevated cardiac sympathetic input to compensate for changes in the intrinsic properties of the diabetic heart.

SAT0177 Primary Raynaud's Phenomenon and Nailfold Videocapillaroscopy: Age-Related Changes in Capillary Morphology

BackgroundPrimary Raynaud's phenomenon (PRP) represents a benign condition observed in healthy subjects. It is usually due to an exaggerated response to the physiological cold-induced vasospasm [1].ObjectivesTo detect by nailfold videocapillaroscopy...

Optimal plane for nerve sparing total mesorectal excision, immunohistological study and 3D reconstruction: an embryological study

Genito-urinary complications are frequent after rectal surgery and are often due to nerve damage. The relationship between the pelvic nerves and surgical planes are unclear. The aim of the study was to determine the relationship between the inferior hypogastric plexus and the fascia of the lateral pelvic wall and between Denonvilliers' fascia and the efferent branches of the inferior hypogastric plexus. Computer-assisted anatomical dissection was used. Serial histological sections were made from six human foetuses and a male adult. Sections were stained with haematoxylin and eosin, Masson's trichrome and immunostainings. The sections were then digitalized and reconstructed in three dimensions. The inferior hypogastric plexus was situated in a virtual space between the fascia propria of the rectum and the fascia on the upper surface of the levator ani. During the lateral dissection, the optimal surgical plane is the plane of the fascia propria of the rectum. We located Denonvilliers' fascia in three dimensions. It plays the role of a protective sheet for the neurovascular bundle. The optimal plane for nerve preservation is situated behind Denonvilliers' fascia. This study has enabled a clear visualization of the optimal planes to perform total mesorectal excision while ensuring nerve preservation. Three-dimensional visualization clearly helps to bridge the gap between histological examination and the findings of surgery.

Branch ligatures and blood aspiration for post-traumatic superficial temporal artery pseudoaneurysm: surgical technique

The aim of this study is to report a new minimally invasive technique of superficial temporal artery (STA) pseudoaneurysm treatment. Several surgical options have been employed to treat STA pseudoaneurysms. To address this rare condition, the employed techniques are ligation and excision of the aneurysm, endovascular coil embolization or percutaneous ultrasound-guided thrombin injection. Between techniques no significant differences are reported in terms of outcomes. The decision to adopt a technique depends on STA pseudoaneurysm morphology and surgeon preference. In the present report, STA pseudoaneurysm afferent and efferent branches were identified by ultrasound in a 92-year-old female. Under local anaesthesia, these branches were ligated through small skin incisions. STA pseudoaneurysm decompression was obtained by an 'over the needle aspiration'. A compressive dressing was left in space for 48 h.

Multiple reimplantation technique for treatment of complex giant aneurysms of the middle cerebral artery: technical note

Giant middle cerebral artery (MCA) aneurysms are among the most challenging neurovascular lesions, especially when the M2 and M3 branches are incorporated into the aneurysm. Here we report on two cases with complex MCA aneurysms, in which double and triple arterial reimplantation of the efferent vessels into a saphenous vein graft (SVG) was applied to reconstruct the MCA tree, allowing final trapping of the aneurysm. In the first case, a 41-year-old woman presented with a partially thrombosed giant MCA aneurysm including three efferent branches. Two superior trunks were disconnected and reimplanted onto an SVG fed by the external carotid artery (ECA). Following anastomosis between the SVG and the inferior trunk, the aneurysm was trapped. The second case is a 67-year-old man with recurrent giant MCA aneurysm incorporating two efferent M2 branches. First, the superior trunk was reimplanted onto an SVG, then the SVG was anastomosed to the inferior trunk. Finally the afferent M1 was clipped. Intraoperative indocyanine green (ICG) videoangiography (FLOW 800) was used for studying bypass patency. In both cases, successful bypass patency was demonstrated by ICG videoangiography. Postoperative digital subtraction angiography (DSA) confirmed bypass patency. The first case was discharged without any neurological deficit. The second case suffered from bleeding due to refilling of the aneurysm via the inferior M2. An additional clip was placed on the inferior M2 in a second step. The patient was discharged with weakness of the left arm. Reconstructing an MCA bifurcation or trifurcation combining multiple arterial reimplantation is effective for treatment of selective cases of complex MCA aneurysms.

Microcatheter Looping Technique for Coil Embolization of Complex Configuration Middle Cerebral Artery Aneurysms

Protection techniques using stents or microcatheters allow treatment of aneurysms with complex configurations by coil embolization. However, the application of these techniques is occasionally limited in wide-neck middle cerebral artery (MCA) aneurysms with acute angularity of the efferent branch vessel. We describe a looping technique for passage of a microcatheter and microwire into the acutely angled efferent branch vessel without navigating the system through the aneurysm lumen. To select the acutely angulated branch, a looped microcatheter was advanced near the orifice of the distal acutely angled branch vessel, followed by microwire passage through the looped microcatheter into the efferent vessel. The microcatheter loop was straightened after the microwire had been sufficiently advanced. The microcatheter was then navigated into the distal branch vessel over the advanced microwire. A total of 36 wide-neck MCA aneurysms were successfully treated using this looping method. This technique was used to pass the microcatheter for stent protection in 13 patients and for microcatheter protection in 23. The method was most commonly used for aneurysms located at the M1 trunk (n = 21), followed by the MCA bifurcation (n = 15). Complete or near-complete endosaccular occlusion was achieved in 31 aneurysms. There were no complications related to looping the microcatheter. This microcatheter looping technique facilitates safe entry into the distal branch during coil embolization of wide-neck MCA aneurysms incorporating the origins of acutely angulated branches.

Ethical and deontological issues in Transfusion Medicine.

Ethical and deontological issues in Transfusion Medicine.

175. Optimal surgical plans to perform total mesorectal excision, while ensuring nervous conservation – Clear-cut answers thanks to a 3D histological approach

Introduction: Despite continuous surgical improvements, genito urinary sequelae remain frequent after rectal surgery for cancer. Total mesorectal excision is considered as the standard technique for oncological rectal surgery. However, relationships between pelvic nerves and surgical plans remain very unclear and subject to contradictory interpretations. Such knowledge and accurate 3D positioning is fundamental to expect an optimal nervous conservation after surgery. We studied the relationships between the inferior hypogastric plexus and the lateral fascia of the pelvis and between Denonvilliers' fascia and efferent branches of the IHP, and could give a comprehensive 3D representation of these different elements.

Cannabinoid Receptor 1 in the Vagus Nerve Is Dispensable for Body Weight Homeostasis But Required for Normal Gastrointestinal Motility

The cannabinoid receptor 1 (CB(1)R) is required for body weight homeostasis and normal gastrointestinal motility. However, the specific cell types expressing CB(1)R that regulate these physiological functions are unknown. CB(1)R is widely expressed, including in neurons of the parasympathetic branches of the autonomic nervous system. The vagus nerve has been implicated in the regulation of several aspects of metabolism and energy balance (e.g., food intake and glucose balance), and gastrointestinal functions including motility. To directly test the relevance of CB(1)R in neurons of the vagus nerve on metabolic homeostasis and gastrointestinal motility, we generated and characterized mice lacking CB(1)R in afferent and efferent branches of the vagus nerve (Cnr1(flox/flox); Phox2b-Cre mice). On a chow or on a high-fat diet, Cnr1(flox/flox); Phox2b-Cre mice have similar body weight, food intake, energy expenditure, and glycemia compared with Cnr1(flox/flox) control mice. Also, fasting-induced hyperphagia and after acute or chronic pharmacological treatment with SR141716 [N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-3-pyrazole carboxamide] (CB(1)R inverse agonist) paradigms, mutants display normal body weight and food intake. Interestingly, Cnr1(flox/flox); Phox2b-Cre mice have increased gastrointestinal motility compared with controls. These results unveil CB(1)R in the vagus nerve as a key component underlying normal gastrointestinal motility.

Long-Term Outcome of Single Institutional Experience with Conservative and Surgical Management for Renal Artery Aneurysm

BackgroundSpontaneous rupture risk of a renal artery aneurysm (RAA) is extremely low. Indications for surgical repair of RAA remain uncertain. ObjectiveLong-term outcomes of conservative therapy and surgical repair were evaluated. PatientsThe study included 58 patients (17 males, 41 females) who were diagnosed with RAA during the last 21 years. Median age at the time of diagnosis was 62 (19–85) years, and the median follow-up 69 months (range 3–216). MethodsThe patients were divided into two groups, conservative group (n = 30) who had been followed with blood pressure control, and treatment group (n = 29), who underwent an intervention. ResultsMultiple efferent aneurysmal branches were observed in seven conservative and 16 treatment cases (P = .002). The median maximum diameter of the aneurysm was lower in the conservative than the treatment group (15 versus 25 mm, P = .005). Two conservative group cases showed increases in aneurysm size during follow-up. The hypertensive state showed essentially no change in either group during the follow-up. Renal function decreased with age similarly both in conservative and treatment groups. ConclusionsOur conservative management criteria for RAA are justifiable and even too strict.

Flow Diverters Can Occlude Aneurysms and Preserve Arterial Branches: A New Experimental Model

FDs are new intracranial stents designed to occlude aneurysms while preserving flow to jailed arterial branches. We tested this fundamental principle in a new aneurysm model. Canine lateral wall aneurysms, featuring a branch located immediately opposite the aneurysm, were created in 16 animals to study the effects on aneurysm or branch occlusion using single HP stents (n = 4), 2 overlapping HP stents (n = 4), or an FD (n = 8). Two other animals, in which an efferent arterial branch was anastomosed to the aneurysm fundus, were also treated with FDs. Angiographic results after deployment, at 2 weeks, and at 3 months were scored using an ordinal scale. The metal porosity of the FSS and the amount of FSS neointima formation was determined by postmortem photography. FDs led to better angiographic occlusion scores compared with HP stents (P = .026). FDs were significantly more likely to occlude the aneurysm than the branch (P = .01). When the branch was switched to originate from the aneurysm fundus, the FDs became ineffective (0/2). Neointimal closure of the aneurysm ostium was significantly better with FDs than with single or double HP stents (P = .039). Angiographic occlusion correlated with metallic porosity and neointimal tissue coverage (Spearman ρ = -0.81; P = .001). In this study, flow diverters occluded lateral wall aneurysms more readily than branches. Metal device porosity strongly influenced the occlusion rate.

Erratum to: Preservation of Genital Innervation in Women During Total Mesorectal Excision: Which Anterior Plane?

Fig. 4 Three-dimensional (3D) view of fetus intrapelvic organs with pelvic nerves. Superior infraperitoneal 3D view of a 30-week-old female fetus: intrapelvic organs with immunolabeled pelvic nerves showing the position of the inferior hypogastric plexus (IHP) on the lateral aspects of the rectum. From the IHP, efferent branches rise in distal directions: postero-inferior for the rectal wall, lateral for the levator ani muscles, and antero-inferior to form the NVBs. Some fibers from the NVBs branch medially to innervate the posterior vaginal wall. More caudally, the bundle puts out fibers in three major projections: an anterior projection for the urethral sphincter complex, an anterolateral projection (the cavernous nerve) that travels anterolaterally to the vagina to reach the corpora cavernosa, and a posterolateral projection (the spongious nerve) that continues posterolaterally to the vagina to innervate the corpus spongiosum. In inset, blue arrows show the directions of the IHP and NVB main terminal efferences. Ur urethra The online version of the original article can be found under doi:10.1007/s00268-011-1313-2.

2201 LONG-TERM OUTCOMES OF RENAL ARTERIAL ANEURYSM; A COMPARISON BETWEEN CONSERVATIVE THERAPY AND SURGICAL TREATMENTS IN SINGLE CENTER ANALYSIS

INTRODUCTION AND OBJECTIVES: Since spontaneous rupture risk assumed to be extremely lower in renal arterial aneurysm (RAA), the rarity and variable clinical course has annoyed surgical indication of RAA. Long-term follow-up study of conservative management for RAA has been scarcely reported. The aim of this study was to evaluate long-term outcomes of active surveyllance and surgical repair in patients with RAA. METHODS: The study included 58 patients who were diagnosed as RAA over the past 21 years (male: 17, female: 41). Median age at the time of diagnosis was 62 years (19–85 year range), and the median follow-up period was 69 months (3–216 month range). The conservative group (n 30) included patients who have been followed under strict blood pressure control. The treatment group (n 29) included patients who underwent surgical repair or radiological intervention. Differences between the groups in clinical backgrounds, RAA characteristics, clinical course and renal function were evaluated. Our tentative criteria of patient selection for the conservative group was age at 40 years or older, 20 mm or smaller in maximum aneurysm diameter and high degree of aneurysmal calcification. They had been followed up under careful blood pressure control and evaluated their renal function, RAA image on CT scan / ultrasonogram annually. RESULTS: Twenty-one cases of the treatment group underwent ex-vivo aneurysmal repair, while 4 cases underwent in-situ repair. In the other 4 cases, 2 underwent nephrectomy and 2 underwent trans-arterial embolization. Smoking habits at the time of diagnosis were found in 5 (16.7%) or 15 (51.7%) cases in the conservative or treatment group, respectively (p 0.024). Multiple efferent aneurysmal branches were found in 7 (23.3%) or 16 (55.2%) cases, respectively (p 0.002). Median maximum diameter of aneurysm was significantly lower in conservative group (15 vs. 25mm, p 0.005). All patients were alive except for 2 cases in conservative group, who were died in the other reasons. Increasing in size of RAA was observed in only 2 cases of conservative group. Cumulative postoperative complications (autotransplanted graft dysfunction or post-operative urinary tract complication, et al.) occurred 15/27 (55.6%) in the treatment group. No significant difference was observed in renal function between the two groups. CONCLUSIONS: The conservative approach of RAA could be expanded under appropriate management for hypertension and careful observation for RAA, otherwise surgical repair would be with discretion for obviating the surgical adverse events.