Reconstructive Vascular Surgery Research Articles

Ca2+ Signalling in Damaged Endothelium and Arterial Remodelling: Do Connexin Hemichannels Provide a Suitable Target to Prevent In-stent Restenosis?

A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and forms a multifunctional transducing organ that regulates cardiovascular homeostasis. Disruption of endothelial integrity, as a result of either angioplasty or stent deployment, may produce a late in-stent restenosis and limit the beneficial outcome of reconstructive vascular surgery. Restoration of endothelial lining requires spreading, migration and proliferation of ECs nearby the lesion site. Intracellular Ca2+ signalling plays a major regulatory role in stimulating wound healing, however, the mechanism whereby injury increases Ca2+ levels at the wound edge is still unclear. The analysis of Ca2+ signals elicited by scraping an endothelial monolayer in vitro suggested the involvement of intracellular Ca2+ release from InsP3-sensitive stores and Ca2+ entry through unknown ion channels in the plasma membrane. Recent studies carried out on excised rat aorta highlighted a novel role for connexin hemichannels (CxHcs) in mediating Ca2+ entry in injured endothelium. Understanding the signal transduction pathway leading to EC activation is likely to provide novel targets to design therapeutic applications aiming to restore endothelial integrity and treat cardiovascular diseases. Therefore, alternative drug-eluting stents might be devised to trigger CxHc opening and reduce in-stent restenosis following vascular regenerative surgery.

Extracellular matrix graft for vascular reconstructive surgery: evidence of autologous regeneration of the neoaorta in a murine model

The study aimed to evaluate the efficacy of the porcine small intestine submucosa extracellular matrix (SIS-ECM) in a murine model, as a possible vascular patch for clinical use in reconstructive vascular and potentially cardiac surgery. Fifteen adult male Sprague Dawley rats and five green fluorescent protein (GFP) rats were enrolled in this study. The SIS-ECM graft (6 mm long, 4 mm wide) was implanted for patch plasty on the abdominal aorta of the animal, after excising part of its anterior wall. Histology and immunohistochemistry were used to evaluate the results at 15, 30, 90 and 180 days post-surgery. Graft re-population was demonstrated 15 days after implantation. The luminal surface of the regenerating tissue was partially covered by endothelial cells, and intimal hyperplasia occurred in the central part of the graft. Complete re-endothelialization of the patch with smooth muscle cells colonizing the graft and acting as the neoaortic wall was observed after 30 days. Near complete absorption of the biomaterial was observed after 180 days. No inflammatory cell reaction occurred. All animals survived and no graft aneurysm was observed. A SIS-ECM patch allowed the colonization of host endothelial and smooth muscle cells in the graft. This material may be an ideal substitute for reconstructive vascular surgery, and its use could be extended to surgical repair of cardiac defects.

Effect of Triclosan‐Coated Sutures on Incidence of Surgical Wound Infection after Lower Limb Revascularization Surgery: A Randomized Controlled Trial. By Turtiainen et al. DOI:10.1007/s00268‐012‐1655‐4

This prospective, randomized, multicenter, double-blind, parallel group trial by Dr. Turtiainen and her associates in Finland [1] was designed to investigate the potential effect of an antibacterial triclosan-coated suture on the incidence of wound infection in patients undergoing reconstructive vascular surgery. In producing a negative result, the investigators have clarified the role, or lack thereof, of this approach to wound infection. They raise at least two important topics that need to be discussed. The first is the relative dearth of articles in the medical literature reporting negative results, and the other is the matter of wound infections associated with vascular surgery. In general terms, the reluctance of investigators (and journals) to publish negative results contributes significantly to the imbalances that lead to reporting bias. This bias is now assuming more importance than previously because we increasingly depend on meta-analyses to guide medical care via the development and use of guidelines and protocols. The absence of negative studies in the literature inevitably leads to the production of conclusions from such analyses that are biased toward the positive. To reduce such misleading tendencies, the publication of carefully designed and wellconducted studies such as this one should be encouraged even when the results are negative [2]. The problem studied in the article by Turtiainen et al. [1]—infection associated with reconstructive vascular surgery—is a source of particular anxiety because of its potentially disastrous consequences, especially in this age of methicillin-resistant Staphylococcus aureus (MRSA) and health care-associated infections. The consequences of infection can be catastrophic. ‘‘... outcomes often worse than those of the natural history of the condition that led to implantation [of the graft]’’ [3]. Infection of a prosthetic conduit not uncommonly leads to limb loss or death. Add to this mix the propensity of groin wounds disproportionately to be affected and the preponderance of diabetic patients involved and we understand why vascular surgeons should be so concerned about this topic. The incidence of surgical-site infections (SSIs) after vascular surgery varies widely from one publication to another, as does the definition of wound infection. The incidence reported here is not out of keeping with other reports. Vascular surgery is often regarded largely as ‘‘clean’’ surgery in that incisions are made through apparently uncontaminated tissue, and the procedures do not involve opening any hollow viscus. Published audits of wound infection in vascular surgery report wide variations in wound infection rates. Those at the lower end probably involve a certain amount of selection bias as authors strive to demonstrate the excellence of their practice. Studies such as the one published here almost certainly give a more accurate picture of the real world. Clear definition of what constitutes an SSI and impartial, blinded follow-up are important aspects of this accuracy. It seems possible that infection rates outside the confines of a trial (where patients are known to receive more error-free care) are even higher than those discovered here. So what is to be done about the problem of wound infection in vascular surgery? It seems that there is no magic bullet yet, and we therefore must depend upon rigorous application of techniques and policies that are well established. Appropriate prophylactic antibiotics, meticulous maintenance of intraoperative sterility, accurate surgical technique avoiding excessive dissection and cautery, and most importantly careful patient selection have major roles in the minimization of this substantial risk. P. Rogers (&) Western Infirmary, Glasgow G11 6NT, UK e-mail: pn.rogers@btinternet.com

Vasa vasorum quantification in human varicose great and small saphenous veins

Recent research regarding saphenous vasa vasorum (VV) has focused on two main topics: the VV during varicogenesis in chronic venous insufficiency and the VV in saphenous grafts used in reconstructive vascular surgery. Our aim has been (i) to establish a technique for the histological quantification of the VV in human varicose great and small saphenous veins and (ii) to describe the density and distribution of the vasa vasorum within varicose veins. Great (n=11) and small (n=5) saphenous veins (length, 15-40cm) were collected from 12 patients who were undergoing venous stripping due to chronic venous insufficiency (Clinical-Etiology-Anatomy-Pathophysiology class 2-3). The veins were divided into 5-cm long segments. In total, 92 tissue blocks were collected to trace the variability of the density and distribution of the vasa vasorum in the proximo-distal direction. The endothelium was detected by immunohistochemistry using the von Willebrand factor. We quantified the number of microvessel profiles per section area and the relative distance of the microvessels from the outer border of the adventitia. The VV did not exhibit a preferential orientation in the varicose veins. VV density profiles were highest in the middle third of the venous wall and lowest in the inner third of the venous wall. Both the density and distribution of VV were uniform along the veins, and no differences were observed between the great and small saphenous veins. The VV density was statistically independent of the relative distance from the adventitia. The usability of this technique for perioperative frozen sections remains to be tested.

An Anatomical Study of Primary Pattern of Arteries of Upper Limb With Relevance to Their Variations

AbstractA detailed description of the vascular pattern of upper limbs especially their variations in their origin, course and branching pattern is of utmost importance anatomically in general and clinically in particular. These variations have drawn attention of surgeons, physicians, radiologist and interventionists due to the advanced surgical procedures practicd in vascular surgeries, plastic (reconstructive) surgeries and also for diagnostic and therapeutic approaches. 50 cadavers (100 upper limbs) were used for the study, which were dissected as the part of routine dissection for teaching undergraduate students at our institution. Length of the normal and variant arteries with mean, standard deviation, 'p' and 't' values are noted in each of the limbs. The following variations are observed - i) high division of brachial artery ii) higher origin of profunda brachii artery, iii) high origin of radial artery, iv) absence of common interosseous artery. The variations are of particular importance to the surgeons operating in the area, especially for those involved in vascular reconstructive surgeries. So it is prudent to do pre-operative studies of the brachial and antebrachial arteries and their branching patterns, to prevent possible complications post operatively.

A case of true brachial artery aneurysm in an elderly male.

Brachial artery aneurysms are relatively rare and are mostly pseudoaneurysms rather than true aneurysms, as true aneurysms are even rarer entities. Patients can be asymptomatic, or present with pulsatile masses, or ischemia due to associated thromboembolic complications. Distal embolism can occur with transient or minimal ischemic symptoms; however, aneurysm itself can thrombose entirely. The authors report a case of upper limb acute ischemia caused by true brachial artery aneurysm thrombosis in an elderly man, managed by reconstructive vascular surgery.

THE PLACE OF VASCULAR SURGERY IN TREATMENT OF DIABETIC PATIENTS

This article is dedicated to diagnostics, prevention and surgical treatment of vascular complications of diabetes mellitus, particularly prevention of ischemic strokes and treatment of critical ischemia of lower limbs. The main tendency in treatment of brachiocephalic artery lesions nowadays is a surgical intervention in the latent stage of the disease. X-ray endovascular surgical techniques are being increasingly used to treat lesions of lower limbs arteries. Limb preservation is impossible without cooperation of many specialists. It's essential to perform careful out-patient follow up of the patient after vascular reconstructive surgery.

Operative or Interventional Treatment in Infrainguinal Bypass Occlusion: Are There Predictive Factors Affecting Outcome?

Purpose: To evaluate outcome of interventional and surcigal treatment in infrainguinal bypass occlusion and to identify predictive factors affecting therapeutic success. Material and Methods: Over a period of three years 96 patients with infrainguinal bypass occlusion were included in this retrospective study. 52 patients were treated by catheter-directed thrombolysis and 44 patients by reconstructive vascular surgery. Results: 41 grafts could be reopened in thrombolytic group (78.8%), thrombolysis failed in 11 cases (21.2%). 34 grafts were treated successfully by reconstructive vascular surgery (77.3%), 10 grafts couldn’t be reopened or reoccluded within 30 days after surcical therapy. After a median observation time of 14.7 months 30 of 48 (62.5%) bypass grafts treated with intraarterial thrombolysis and 19 of 27 (70.4%) grafts treated with thrombectomy were overall patent. Limb salvage was 81.3% in thrombolytic group and 88.8% in surgery group. No predictive factors affecting outcome could be identified in both groups except the localization of the occluded graft (above/below knee). Conclusion: Infrainguinal bypass occlusion is a serious and challenging complication in vascular surgery. Our study showed similar results for both therapeutic strategies. Despite our data was retrospective with a small number of patients the localization of the occluded graft as predictive pretherapeutic factor was significant in thrombolytic and surgery group. Based on these scientific findings we established a guideline for choice of therapeutic treatment in our institution after searching current literature.

Experience with the treatment of diabetic foot syndrome in Barnaul

The interdisciplinary service organized in the city of Barnaul provides care for patients with diabetic foot syndrome (DFS) including regular medicalexamination, diagnostics, treatment, and prophylactic measures to prevent new lesions and amputations. The service is based on the DiabeticFoot Cabinet of City Hospital No 5, Department of Wound Infections of City Hospital No 3, and Barnaul Prosthetics and Orthopedics Company,a manufacturer of prostheses and orthopedic devices for patients with DFS. These organizations have just begun cooperation with the Departmentsof Vascular Surgery of City Hospital No 5 and Regional Clinical Hospital aimed to perform vascular reconstructive surgery. The joint efforts areexpected to ensure long-term observation of the patients, their education in podiatric self-care, and introduction of the total contact cast method foroff-loading the foot at the stage of ulcer formation with the ultimate purpose of reducing it by 45-75%. Almost 3000 patients (10,000 visits) have beenexamined by specialist of Diabetic Foot Cabinet since 2005; most of them were referred to the group of high and very high risk of foot ulceration. Thenumber of patients with DFS hospitalized for the treatment of wound infections decreased from 263 in 2005 to 122 in 2010 despite a rise in overalldiabetes morbidity among the population of Barnaul. During the same period, the total number of amputations decreased from 269 to 64 and thenumber of high-level amputations from 119 to 3. The number of amputations in the patients regularly visiting the Cabinet is much lower than in thegeneral population and continues to decrease (4.7% in 2008 and 1.6% in 2010). 23% of the patients with DFS referred to the Cabinet underwentamputation in 2008 compared with 11% in 2010. In 2010, savings to the Altai region budget in direct medical expenditures for the patients with DFSamounted to 41,000,000 rubles (exclusive of management and drug costs and social benefits). The total savings to the budget in direct expendituresfor the hospital-based treatment of such patients during the last 3 years are estimated at more than 108,000,000 rubles.

In vitro evaluation of the antimicrobial efficacy of a new silver-triclosan vs a silver collagen-coated polyester vascular graft against methicillin-resistant Staphylococcus aureus

Vascular graft infection is a rare but serious complication of vascular reconstructive surgery. This in vitro study investigated the antimicrobial efficacy of a new, silver-triclosan collagen-coated polyester vascular graft compared with a silver collagen-coated polyester vascular graft alone during the first 24 hours. The antimicrobial efficacy of the investigated vascular grafts was assessed by performing a time-kill kinetic assay following Clinical and Laboratory Institute Standards-approved guidelines M26-A. For the purpose of the experimental study, the ATCC 33591 strain of methicillin-resistant Staphylococcus aureus (American Type Culture Collection, Manassas, Va) was used. All assays were repeated sixfold. Bacterial survival numbers were obtained at 1, 4, 8, 12, and 24 hours using a standard plate count procedure. Bactericidal activity was defined as a 3 log(10) reduction factor (logRF), according to the approved guideline M26-A. Both antimicrobial vascular grafts achieved >3 logRF and fulfilled the efficacy criterion for bactericidal activity but performed differently in their speed of antimicrobial action. The silver-triclosan vascular graft achieved 3.37 logRF after 8 hours, and the silver vascular graft showed a 4.19 logRF after 24 hours. The silver-triclosan graft yielded significantly lower colony-forming units/mL counts after 4 hours compared with the silver graft (4.29 × 10(4) vs 1.03 × 10(6); P = .031). Both antimicrobial collagen-coated polymer vascular grafts showed bactericidal activity against methicillin-resistant Staphylococcus aureus in vitro. Although the silver-triclosan vascular graft showed a faster antimicrobial efficacy, the silver graft exhibited its antimicrobial properties after 24 hours. Which concept will protect an implanted vascular prosthetic graft better from bacterial contamination and subsequent infection needs to be investigated further in in vivo animal and clinical studies.

First textbook in vascular surgery

First textbook in vascular surgery

A simple technique to prevent and correct graft vessel kinking in the subcutaneous tunnel: Technical note

Object A simple method for preventing and correcting graft kinking for vascular reconstructive surgery through a subcutaneous tunnel is described. Patients and methods Using a chest tube, 1-0 silk suture and cerebral aneurysmal clips, the problem of postoperative ischemic complications due to kinking can be solved. Conclusion The main advantages of this method are its simplicity and low cost. Using this method does not require any special equipment and the problem of postoperative ischemic complications due to vascular injury, kinking and vasospasms can be addressed.

Cryopreserved, cultured, allogenic, human epidermal grafts for the treatment of chronic ischemic ulcers: A report on two cases

Cultured, allogenic, human epidermal grafts have been successfully used to treat extensive burns, donor sites, leg ulcers, and eroded areas in recessive dystrophic epidermolysis bullosa. The following report describes the use of cryopreserved cultured human epidermal allografts in the treatment of long-standing ischemic ulcers unresponsive to conventional medical therapy in two patients who had previously undergone unsuccessful vascular reconstructive surgery. A marked reduction in ulcer size as well as rapid pain relief was achieved in both patients. In selected cases the use of epidermal grafts as a biologic topical therapy could represent an alternative to other medical treatments. However, thus far, only a few cases have been reported and the uncertain short- and long-term results as well as the excessive costs may limit the widespread application of this treatment modality.

Pulse oximetry: An adjunct in the management of penetrating vascular trauma

Twenty-eight patients with penetrating trauma to the extremity were assessed by history, physical examination, and pulse oximetry. The group was divided by pulse oximetry greater or less than 92%. Group A, 17 patients (14 men, 3 women), mean age 22 years, had a pulse oximeter reading of greater than 92% and an arteriogram, but had no surgical intervention. There was no adverse outcome or episodes of adverse outcome. None had any adverse sequelae. Group B, 11 patients (8 men, 3 women), mean age 24 years, had pulse oximetry readings from 0% to 88%; all patients in this group required vascular reconstructive surgery based on history, physical examination, and arteriogram; two lost their limb(s).

Factors related to outcome of neuroischemic/ischemic foot ulcer in diabetic patients

Peripheral vascular disease (PVD) is an important limiting factor for healing in neuroischemic or ischemic diabetic foot ulcer. The purpose of this study was to identify factors related to healing in patients with diabetes with foot ulcers and severe PVD. Patients with diabetes with a foot ulcer, consecutively presenting at a multidisciplinary foot center with a systolic toe pressure <45 mm Hg or an ankle pressure <80 mm Hg were prospectively included, followed according to a preset program, and with the exception of specified exclusions, subjected to angiography offered vascular intervention when applicable. All patients had continuous follow-up until healing or death irrespective of the type of vascular intervention. One thousand one hundred fifty-one patients were included. Eighty-two percent had a toe pressure <45 mm Hg and 49% had an ankle pressure <80 mm Hg. Eight hundred one patients (70%) underwent an angiography. Out of these, 63% had vascular intervention, either percutaneous transluminal angioplasty (PTA; 39%) or reconstructive surgery (24%). Nine percent of the patients had one or more complications after angiography. PTA was multisegmental in 46% and to the crural arteries in 46%. Reconstructive surgery was distal in 51%. Age (P < .001), renal function impairment (P = .005), congestive heart failure (P = .01), number and type of ulcer (P < .001), and severity of PVD (P = .003) affected the outcome of ulcers. PTA and reconstructive vascular surgery increased the probability of healing without amputation (odds ratio [OR], 1.77 and 2.05, respectively). Probability of ulcer healing is strongly related to comorbidity, extent of tissue involvement, and severity of PVD in patients with diabetes with severe PVD.

832 PROGNOSTIC CLINICAL PARAMETERS TO PREDICT THE NECESSITY OF RECONSTRUCTIVE VASCULAR SURGERY FOR PATIENTS WHO UNDERGO POSTCHEMOTHERAPY RETROPERITONEAL LYMPH NODE DISSECTION (PC-RPLND) FOR ADVANCED NONSEMINATOUS GERM CELL TUMORS (NSGCT). RESULTS OF THE GERMAN TESTICULAR CANCER STUDY GROUP (GTCSG) AND THE ASSOCIATION OF UROLOGIC ONCOLOGY (AUO)

You have accessJournal of UrologyPenis/Testis/Urethra: Benign & Malignant Disease1 Apr 2011832 PROGNOSTIC CLINICAL PARAMETERS TO PREDICT THE NECESSITY OF RECONSTRUCTIVE VASCULAR SURGERY FOR PATIENTS WHO UNDERGO POSTCHEMOTHERAPY RETROPERITONEAL LYMPH NODE DISSECTION (PC-RPLND) FOR ADVANCED NONSEMINATOUS GERM CELL TUMORS (NSGCT). RESULTS OF THE GERMAN TESTICULAR CANCER STUDY GROUP (GTCSG) AND THE ASSOCIATION OF UROLOGIC ONCOLOGY (AUO) Axel Heidenreich, Klaus Peter Diekmann, Hans Schmelz, Christoph Winter, and David Pfister Axel HeidenreichAxel Heidenreich Aachen, Germany More articles by this author , Klaus Peter DiekmannKlaus Peter Diekmann Hamburg, Germany More articles by this author , Hans SchmelzHans Schmelz Koblenz, Germany More articles by this author , Christoph WinterChristoph Winter Düsseldorf, Germany More articles by this author , and David PfisterDavid Pfister Aachen, Germany More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.652AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES PC-RPLND remains an integral part of the multimodality treatment for advanced NSGCT. The need to resect and to replace the major retroperitoneal vessels must be known preoperatively to enable complete resection of the residual masses. METHODS PC-RPLND was performed in 411 patients with NSGCT and normalized (81%) or plateauing (19%) tumor markers following 3–4 cycles PEB/PEI. PC-RPLND was performed in 5 institutions with a variable surgical frequency of 14 to 158 PC-RPLNDs. Good, intermediate, and poor prognosis according to the IGCCCG criteria was identified in in 59.8%, 21.2%, and 19% respectively. RESULTS Resection of the inferior vena cava was performed in 28 (6.81%) patients, resection of the abdominal aorta was necessary in 13 (3.16%) patients. In 29/41 (70.7%) adjunctive surgical procedures such as nephrectomy, small bowel resection, ureteral resection had to be performed to ensure complete resection of the residual masses. Histologically vital carcinoma or mature teratoma was identified in 78.1% of the resected vascular specimens. Mean time of surgery was 295 (243–615) Min., mean blood loss was 690 (350 – 3400) ml. Good prognosis was identified in 15.4%, an intermediate and poor prognosis was present in 41%and 43.6%, respectively. Of all 411 patients involvement of the major retroperitoneal vessels was found in 3.2%, 18.4% and 21.8% with good, intermediate, and poor prognosis, respectively. The mean tumor diameter was 5.9 (1.0 – 32) cm for the entire cohort and 9.8 (4–32) cm for the cohort of patients with vascular surgery. Significant prognosticators to predict vascular involvement were identified by multivariate analysis: intermediate/poor prognosis, number of cycles of chemotherapy, tumor diameter > 14cm, circumferential encasement of > 50% of the vessel diameter. CONCLUSIONS Complete resection of the inferior vena cava or the abdominal aorta during PC-RPLND is necessary in about 10% of patients. The identified predictors enable already preoperatively a risk adapted interdisciplinary approach for complete resection of the residual masses in an experienced centre. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e335 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Axel Heidenreich Aachen, Germany More articles by this author Klaus Peter Diekmann Hamburg, Germany More articles by this author Hans Schmelz Koblenz, Germany More articles by this author Christoph Winter Düsseldorf, Germany More articles by this author David Pfister Aachen, Germany More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Update on Wartime Vascular Injury

Data from the Joint Theater Trauma Registry has led to changes in combat casualty care for Operations Iraqi and Enduring Freedom compared with previous wars. Currently, all recognized vascular injuries are repaired before leaving Iraq or Afghanistan. Extremity injuries are prevalent, accounting for the majority of reconstructive vascular surgery performed. Abdominal and chest injuries are less frequent in US forces than in local population, most likely because of the use of body armor. Increased use of tourniquets, modern advances in damage control resuscitation, and use of temporary vascular shunts are factors of increased survival. Use of autogenous or prosthetic grafts, vascular shunting, diagnostic imaging, and negative pressure wound therapy should continue to be encouraged. All of these advances contributed to an increase in amputation-free survival rates. The management of combat-related vascular injuries has progressed to the point of achieving reasonable outcomes for our country's military casualties.

Ca2+ Signalling in Damaged Endothelium: Do Connexin Hemichannels Aid in Filling the Gap?

A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and forms a multifunctional trans- ducing organ that regulates cardiovascular homeostasis. Disruption of endothelial integrity, as a result of either angioplasty or stent deployment, may produce a late in-stent restenosis and limit the beneficial outcome of reconstructive vascular surgery. Restoration of endothelial lining requires spreading, migration and proliferation of ECs nearby the lesion site. Intracellular Ca 2+ signalling plays a major regulatory role in stimulating wound healing, however, the mechanism whereby injury increases Ca 2+ levels at the wound edge is still unclear. The analysis of Ca 2+ signals elicited by scraping an endothelial monolayer in vitro suggested the involvement of intracellular Ca 2+ release from InsP3-sensitive stores and Ca 2+ entry through unknown ion channels in the plasma membrane. Recent studies carried out by our group on excised rat aorta highlighted a novel role for connexin hemichannels (ChHcs) in mediating Ca 2+ entry in injured endothelium. This observation sheds new light on the notion that the rate of wound repair is reduced in ECs transfected with dominant negative connexin inhibitors. Understanding the signal transduction pathway leading to EC activation is likely to provide novel targets to design therapeutic applications aiming at restoring endothelial integrity and treating cardiovascular diseases.

Obstructive uropathy due to inflammatory abdominal aortic aneurysm occurring 18 years after surgical repair of an atherosclerotic aneurysm.

Sir, Chronic periaortitis has a wide range of causes [1]. Obstructive uropathy associated with chronic periaortitis complicating abdominal aortic aneurysm (AAA) repair is well recognized and tends to occur early within 12 months of AAA repair. It is unusual for this to occur many years after surgery. A 71-year-old male was referred to the renal team after an emergency hospital admission by the medical team with acute kidney injury. Serum creatinine was 774 µmol/L (eGFR 7 mL/min/L), having been 140 µmol/L (eGFR 47 mL/min/L) 4 months previously. There was history of an atherosclerotic AAA open repair with an aortic graft in 1990. In 1994, the patient had a surgical exploration and evacuation for retroperitoneal haematoma. In 1995, the patient underwent surgical repair for leaking AAA. The proximal half of the graft was resected and replaced with a second Gelsoft graft (rifampicin soaked). In September 2008, the patient was admitted to our hospital with malaise, anorexia and oliguria. On examination, there was a pulsatile abdominal mass just lateral (left) to his midline laparotomy scar. An abdominal CT scan showed a large infrarenal AAA measuring 9.2 cm. The right kidney was of normal size but severely hydronephrotic with a hydroureter extending down to the level of the aortic bifurcation. The left kidney was small and also hydronephrotic (Figure 1). There was extensive fibrosis noted at the level of the aortic bifurcation associated with obstructive uropathy (Figure 2). Fig. 1 Bilateral hydronephrotic kidneys. Fig. 2 A large infrarenal abdominal aortic aneurysm with extensive fibrosis. The patient remained hypotensive with a poor urine output. He subsequently deteriorated and died 4 days after admission. Early hydronephrosis developing within the first year occurs in 10–20% of patients following surgical graft repair of AAA. The most probable cause for this is mechanical due to the compression of the ureter against the native iliac artery from the anteriorly placed graft [2]. In a prospective study of 101 patients who underwent aortofemoral and aortoiliac reconstructive surgery, 12% of patients developed mild to moderate hydronephrosis. All patients were asymptomatic, and the obstruction resolved spontaneously in 10 of 11 patients within 3 months of onset. The incidence of delayed hydronephrosis occurring 1 year or more post surgical repair is unknown. This complication may be relatively common after reconstructive vascular surgery as in our patient, especially in association with infected grafts [3]. The mechanism for the development is not fully understood. The most widely held view is that this complication develops secondary to an inflammatory process causing fibrosis [4]. The long time interval is unusual and suggests perhaps a different mode of inflammatory pathways compared to what is commonly seen in early obstructive uropathy associated with surgical graft repair of AAA. More research is needed to elucidate the mechanisms underlying chronic periaortitis [5]. Conflict of interest statement. None declared.

対側閉塞を伴った頚部内頚動脈狭窄症４例のＰｏｓｉｔｒｏｎ Ｅｍｉｓｉｏｎ Ｔｏｍｏｇｒａｐｈｙ （ＰＥＴ）による血行再建術前後の脳循環代謝の評価

We analyzed changes in cerebral hemodynamics due to reconstructive vascular surgery using positron emission tomography (PET) in 4 patients with severe internal carotid artery (ICA) stenosis and contralateral ICA occlusion. Three patients had carotid artery stenting (CAS), while the remaining had superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery. Preoperative cerebral blood flow (CBF) studies of all patients demonstrated various decreases in CBF in a resting state and cerebral vascular reactivity (CVR) to acetazolamide (ACZ) and an increase in the oxygen extraction fraction (OEF) on both sides. These parameters improved on both sides after CAS was performed. Our results indicate that CAS performed on a stenosis contralateral to the site of occlusion will improve cerebral hemodynamics bilaterally and indirectly, patient prognosis. But further clinical trials are required to determine whether CAS significantly reduces in stroke above the occlusion.