Early and long-term results of open repair of inflammatory abdominal aortic aneurysms: Comparison with a propensity score-matched cohort.

OBJECTIVE: The aim of our study was to compare early and long-term results of open repair of patients with inflammatory abdominal aortic aneurysm (IAAA) with matched cohort of patients with abdominal aortic aneurysm (AAA). METHODS: This retrospective single-center cohort study used prospectively collected data from an institutional registry from 1786 patients between 2009 and 2015. Patients with IAAA and AAA were matched by propensity score analysis controlling for demographics, baseline comorbidities, and AAA parameters in a 1:2 ratio. Patients were followed for 5 years. RESULTS: There were 76 patients with IAAA and 152 patients with AAA. Patients with IAAA had more common intraoperative lesion of intraabdominal organs (P = .04), longer in-hospital (P = .035) and intensive care (P = .048) stays and a higher in-hospital mortality rate (P = .012). There were four patients (5.26%) with in-hospital lethal outcome in IAAA there were no deaths in the AAA group. During the follow-up, there was no difference in survival (χ2 = 0.07; DF = 1; P = .80) and overall aortic related complications (χ2 = 1.25; DF = 1; P = .26); however, aortic graft infection was more frequent in IAAA group (P = .04). CONCLUSIONS: Open repair of IAAA is challenging and comparing to AAA carries a higher perioperative risk and long-term infection rate, even in high-volume centers. The main causes of complications are intraoperative injury of adjacent organs, bleeding, and coronary events. Patients with AAA in a matched cohort showed equal long-term survival, which should be assessed in bigger registries.

Effects of atmospheric pressure dynamics on abdominal aortic aneurysm rupture onset.

BACKGROUND: The effect of atmospheric pressure (AP) on the onset of abdominal aorta aneurysm rupture (RAAA) remains an unanswered question. We have investigated the seasonal variation and the effect of AP dynamics on RAAA by analysing the largest series of intraoperatively confirmed RAAA. PATIENTS AND METHODS: To realize this study we have performed a retrospective analysis of 546 patients with RAAA, operated within 503 days at the Clinic for vascular and endovascular surgery CCS between 1.1.2003 and 31.12.2012. AP data for Belgrade city were obtained from meteorological yearbooks published by the Republic Hydrometeorological Service of Serbia measured at the hydrometeorological station "Belgrade Observatory". Only patients with a residence within the extended Belgrade region, exposed to the similar AP values, were included in the analysis of the AP effect on RAAA. RESULTS: RAAA were observed more frequently during winter and autumn months but without significant difference in comparison to other seasons. Months with higher AP values were associated with a higher RAAA rate (p = 0.0008, R2 = 0.665). A similar trend was observed for the monthly AP variability (p = 0.0311, R2 = 0.374). Average AP values did not differ between days with and without RAAA. However, during the three and seven days periods preceding RAAA AP variability parameters were greater and AP was rising. CONCLUSIONS: Although these pressure differences are very small, higher AP values over longer periods of time as well as greater variability are associated with RAAA. The exact mechanism behind this association remains unclear. The postulation that low AP may precipitate RAAA based on the Laplace law should be discarded.

Bilateral Internal Carotid Artery Occlusion, External Carotid Artery Stenosis, and Vertebral Artery Kinking: May It Be Asymptomatic?

The clinical spectrum of internal carotid artery occlusion ranges from being a completely asymptomatic occlusion to a devastating stroke or death. The prevalence of asymptomatic internal carotid artery occlusion is unknown, particularly for bilateral occlusion. The distal branches of the external carotid artery anastomose with distal branches of the internal carotid artery provide important sources of collateral circulation to the brain. Stenosis of the external carotid artery with ipsilateral/bilateral internal occlusion may result in ischemic sequelae. Coiling or kinking of the vertebral artery is a rare morphological entity that is infrequently reported because it remains asymptomatic and has no clinical relevance. Currently, there is little evidence to support management strategies for this disease entity and no official recommendations for asymptomatic bilateral carotid artery occlusion. We present a case of a 62-year-old female with asymptomatic bilateral internal carotid artery occlusion, bilateral external carotid artery stenoses, and bilateral kinking of the vertebral artery at the V2 segment, who has been successfully managed conservatively for over 5 years. An individualized approach to management of patients with bilateral internal carotid artery occlusion, especially in combination with external carotid artery stenosis and elongation malformations of the vertebral artery is key to a successful strategy.

Chaos and anomalous transport in a semiclassical Bose-Hubbard chain.

We study chaotic dynamics and anomalous transport in a Bose-Hubbard chain in the semiclassical regime (the limit when the number of particles goes to infinity). We find that the system has mixed phase space with both regular and chaotic dynamics, even for long chains with up to 100 wells. The consequence of the mixed phase space is strongly anomalous diffusion in the space of occupation numbers, with a discrete set of transport exponents. After very long times the system crosses over to the hydrodynamic regime with normal diffusion. Anomalous transport is quite universal and almost completely independent of the parameters of the model (Coulomb interaction and chemical potential): It is mainly determined by the initial distribution of particles along the chain. We corroborate our findings by analytical arguments: scaling analysis for the anomalous regime and the Langevin equation for the normal diffusion regime.

Extending the use of air quality indices to reflect effective population exposure.

Although there are tendencies to develop a single common index which would describe an overall air quality status within an area, constructed from a choice of measurements of individual pollutants, indices describing individual pollutants themselves have several potentials which can be used in ways which are not possible with pollutant concentrations. On the case of Belgrade, Serbia, we investigated possibilities of using such indices for comparisons between pollutants, characterization of monitoring sites, and extending their use to include elements of population exposure. A methodology of adjusting the results obtained at monitoring stations located in severe pollution conditions, like street canyons, is proposed and used.

"Close-open-close free-flap technique" for the cover of severely injured limbs.

The treatment of severely injured extremities still presents a very difficult task for trauma orthopaedic surgeons. Despite improvements in technology and surgical/microsurgical techniques, sometimes a limb must be amputated, otherwise severe and potentially fatal complications may develop. There is a well-established belief that severe open fractures should be left open. However, Godina proved wound coverage in the first 72 h (after an injury) to be safe and to bring good final results. So early wound cover (no later than one week after an injury) with well vascularized free flaps became the gold standard. Yet for many patients (some of whom have serious health problems), operative treatment needs to be postponed when they arrive to specialized microsurgical departments for microsurgical reconstruction much later than one week after incurring an injury.  As the definite wound cover period from one week to 3 months seems to be hazardous, especially due to the potential of infection, we developed a safe, original flap technique that prevents infection and covers important structures such as exposed bones, tendons, nerves and vessels. We named this technique the "close-open-close free flap technique". It enables difficult wound cover in any biological phase of the wound, by combining complete flap cover first, with the removal of stitches from one side of the flap after 6-12 h. This technique works very well for borderline cases as well; where even after a complete debridement, dead tissue still remains in the wound - making wound cover very dangerous. Closing completely severe open fractures with free (or pedicled) flaps and removing the stitches on one side after 6-12 h, enables orthopaedic surgeons to safely cover any kind of wound in any biological phase of the wound. Additional debridements, lavages and reconstructions can easily be performed under the flap and after the danger of a serious infection has disappeared, definitive wound closure can be carried out.

Treatment of pediatric vascular injuries: the experience of a single non-pediatric referral center.

BACKGROUND: Pediatric peripheral vascular trauma carries significant risk of complications including limb loss and long-term invalidity. Mechanisms and types of morphological lesions are very diverse. The objectives of this study are to present the experience of a single vascular center in the surgical approach to pediatric vascular injuries, and to analyze the main challenges related to this clinical entity. METHODS: Over a period of 25 years, 17 pediatric peripheral vascular injuries were treated in our institution. Patient's age ranged between one day (newborn) and 15 years (mean: 10.7 years). There were five injuries of upper and 12 injuries of the lower extremity. Preoperative diagnosis was established by clinical examination (N.=4), ultrasonography (N.=1) and angiography (N.=12). Blunt trauma mainly caused arterial thrombosis while penetrating trauma caused arterial laceration or complete transection. Five patients had associated orthopedic injuries (29,4%). There were two posttraumatic pseudoaneurysms and two arterio-venous fistulas. RESULTS: There was no perioperative mortality. Vascular reconstructions included arterial suture (N.=4), thrombectomy + patch angioplasty (N.=1), termino-terminal anastomosis (N.=3), venous anatomic bypass (N.=6), PTFE graft reconstruction (N.=2), and venous extra-anatomic reconstruction (N.=1). Two patients had associated venous injury demanding both arterial and venous reconstruction. In the only case of war trauma treatment ended with limb loss. Other reconstructions presented good early and long-term patency. CONCLUSIONS: Pediatric vascular injuries are extremely challenging issues. Treatment includes broad spectrum of different types of vascular reconstructions. It should be performed by vascular surgeon trained in open vascular treatment or pediatric surgeon with significant experience in vascular surgery.

Subclavian artery aneurysms.

We report the management of 14 subclavian artery aneurysms (13 true, one false) occurring in seven male and seven female patients (average age, 48 years). The aetiology of the aneurysms included thoracic outlet syndrome in eight, atherosclerosis in five and infection in one patient. Twelve aneurysms were of extrathoracic location, while two aneurysms were intrathoracic. Symptoms related to subclavian artery aneurysms were present in 11 patients (compression in four, haemorrhage in one, and ischaemia in six patients), whereas three aneurysms were asymptomatic. All aneurysms were treated surgically. The supraclavicular approach was used in 11 cases, and the combined transsternal and supraclavicular approach was used in two cases. After aneurysm resection, the reconstruction was performed with end-to-end anastomosis in five cases and with saphenous vein or synthetic grafts in eight cases. One infected subclavian artery aneurysm was treated with carotid to axillary saphenous vein bypass after exclusion of the aneurysm. Five associated brachial embolectomies and one bypass from the axillary to the distal brachial artery were performed. In all thoracic outlet syndrome cases, decompression at the thoracic outlet was also performed. There was no operative mortality, and the early patency rate was 100%. The follow-up period was from 6 months to 10 years (mean, 3.92 years). During this period, one patient died of malignancy and one patient required reoperation due to aneurysmal degeneration of the saphenous vein graft. Surgical treatment is recommended for all patients with subclavian artery aneurysms to prevent potential complications.

Accumulation of Mn and Pb in linden (Tilia platyphyllos Scop.) bark and wood.

As an indicator of environmental pollution, we collected tree rings and bark of linden (Tilia platyphyllos Scop.) from four sampling locations in Serbia. Mn and Pb were determined with a spectrochemical method that has an argon-stabilized U-shaped DC arc with aerosol supply as excitation source. Increased concentrations of Mn in linden tree rings and bark were found at the Debeli Lug location, where the Mn transfer factors were largest. The availability of Mn in soil and tree rings was greatly influenced by pH. Since 1950, Mn level decreased more noticeably on acidic soils. Higher concentrations of Pb were found in linden tree rings and bark at the locations Fruska Gora and Zemun. Proximity of the road to Novi Sad at both sites may be a possible reason for this. The Pb transfer factor was highest at Fruska Gora. The ratio of bioavailable elements in soil for Mn and Pb were also calculated. Close correlations between Mn and Pb concentrations in linden tree rings and the ratio of bioavailable elements in soil were seen at all four locations.

Long-term graft occlusion in aortobifemoral position.

BACKGROUND/AIM: Aortobifemoral (AFF) bypass is still the most common surgical procedure used in treatment of aortoiliac occlusive disease. One of the most common complications of AFF bypass procedure is long-term graft oclussion. The aim of this study was to determine the cause of long-term graft occlusion in AFF position, as well as the results of early treatment of this complication. METHODS: This retrospective study, performed at the Clinic of Vascular and Endovascular Surgery, Clinical Center of Serbia in Belgrade, involved 100 patients treated for long-term occlusion of bifurcated Dacron graft which was ensued at least one year after the primary surgical pro cedure. RESULTS: The most common cause of the long-term graft occlusion was the process at the level of distal anastomosis or below it (Z = 3.8, p = 0.0001). End-to-end type of proximal anastomosis has been associated with a significantly increased rate of long-term graft occlusion (Z = 2.2, p = 0.0278). Five different procedures were used for the treatment of long-term graft occlusion: thrombectomy and distal anastomosis patch plasty (46% of the cases); thrombectomy and elongation (26% of the cases); thrombectomy and femoropopliteal bypass (24% of the cases); crossover bypass (2% of the cases) and a new AFF bypass (2% of the cases). The primary early graft patency was 87%. All 13 early occlusions occurred after the thrombectomy associated with patch plasty of distal anastomosis. Thrombectomy with distal anastomosis patch plasty showed a statistically highest percentage of failures in comparison to thrombectomy with graft elongation, or thrombectomy with femoro-popliteal bypass (Z = 2 984, p = 0.0028). Redo procedures were performed in all the cases of early occlusions. In a 30-day follow-up period after the secondary surgery, 90 (90%) patients had their limbs saved, and above knee amputation was made in 10 (10%) patients. CONCLUSION: Long-term AFF bypass patency can be obtained by proximal end-to-end anastomosis on the juxtarenal part of aorta and distal anastomosis on the bifurcation of the common femoral, or on the deep femoral artery.

Cervical plexus block versus general anesthesia in carotid surgery: single center experience.

INTRODUCTION: Carotid endarterectomy may be performed under general (GA) or regional anesthesia (RA). The aim of this study was to evaluate the influence of anesthetic techniques on perioperative mortality and morbidity in patients undergoing carotid surgery. MATERIAL AND METHODS: This prospective study included 1098 consecutive patients operated on between 2003 and 2009 (773 underwent cervical plexus block and 325 underwent general anesthesia). RESULTS: There were 6 deaths, 3 (0.9%) after GA and 3 (0.4%) after RA (p = 0.272). Neurological complication rates were not significantly different (GA 2.1% vs. RA 1.1%, p = 0.212). Incidence of myocardial infarction was similar (GA 0.31% vs. LA 0.39%, p = 0.840). Shunt placement rate was the same in both groups, 11.1%. Total operating time and carotid clamping time were significantly shorter in RA patients (RA: 92 min vs. GA: 106 min; p < 0.001 and RA: 18 min vs. GA: 19 min; p = 0.040). There was no significant difference in number of reinterventions (RA: 1.0% vs. GA: 0.6%; p = 0.504). Pulmonary complications were common in the GA group (RA: 0 vs. GA 0.9%; p = 0.007). Time to first postoperative analgesic was significantly shorter in the GA group (RA: 226 min vs. GA: 139 min; p < 0.001). CONCLUSIONS: Type of anesthesia does not affect the outcome of surgical treatment of carotid disease. However, it should be stressed that fewer respiratory complications, later requirement for first postoperative analgesic, and an awake patient who can continue oral therapy early after surgery, give priority to regional techniques of anesthesia.

Determination of O(3), NO (2), SO (2), CO and PM (10) measured in Belgrade urban area.

O(3), NO(2), SO(2), CO and PM(10) concentrations, simultaneously determined for the first time in Belgrade urban area in the autumnal period of 2005, are presented. The obtained results display similar behaviour of SO(2), NO(2), CO, PM(10) opposite from that of O(3). The weekend effect was also investigated showing diminution of average daily concentrations of SO(2), NO(2), PM(10) and CO for 72, 40, 37 and 42% respectively, and increase of the average daily concentration of O(3) for 56%. Influence of meteorological conditions on observed concentration levels was studied, too. The observed influence of wind speed on the O(3) nightly concentration levels was analyzed pointing to the phenomena of O(3) transport during episodic measurements. To make an identification of possible pollution sources and analyse the influence of meteorological parameters on pollution levels, air back trajectories for high level concentrations episodes were calculated and analysed. A multivariate receptor modelling (Principal Component Analysis, Cluster Analysis) has been applied to a set of data in order to determine the contribution of different sources. It was found that the main principal components, extracted from the air pollution data, were related to gasoline combustion, oil combustion and ozone transport.

Unusual forms of ruptured abdominal aortic aneurysms.

Over 95% of abdominal aortic aneurysms (AAAs) rupture into the retroperitoneal space. Rare types of AAA ruptures comprise ruptures into the inferior vena cava with aortocaval fistula formation (ACF), ruptures into the duodenum with formation of a primary aortoduodenal fistula (ADF), and chronic contained ruptures (CCRs). This article presents a study of 41 cases with unusual forms of ruptured AAA of a series of 506 patients with AAA rupture treated within a 14-year period. There were 11 cases of CCR, 5 cases with ADF, and 25 cases with ACF. The correct preoperative diagnosis was established in 6 (of 11) cases of CCR, in 2 (of 5) cases of primary ADF, and in 13 (of 25) cases of ACF. AAA replacement was performed in 8 cases using a tube graft, whereas a bifurcated graft was used in 31 patients because of the distant extent of the atherosclerotic/aneurysmatic lesions engaging iliac arteries. Two patients had an axillobifemoral bypass. The overall 30-day mortality rate was 19% (8 of 41), with subgroup mortality rates of 0 (CCR), 60% (ADF), and 20% (ACF). Diagnosis and treatment are simplest in cases of CCR and the most complicated in cases of ADF.

[Comparative analysis of conventional and eversion carotid endarterectomy--prospective randomized study].

INTRODUCTION: Studies completed in the last decade of the 20th century showed benefits of carotid endarterectomy in the prevention of stroke in patients with a high-grade stenosis of the internal carotid artery. OBJECTIVE: The aim of this prospective, randomized study was the comparison of early and long-term results between the conventional and eversion carotid endarterectomy, and literature review. METHOD: By the method of random choice, 103 patients were operated on using the eversion carotid endarterectomy and 98 patients using the conventional technique. Operative treatment was carried out under general anaesthesia. Following the clammping of the carotid artery, retrograde blood pressure was determined by a direct puncture of the internal carotid artery above the stenotic lesions. In patients with retrograde pressure below 20 mm Hg intraluminal shunting was routinely performed. Early results were estimated (during the first seven postoperative days) based on mortality, central neurological complications (stroke, TIA) and cranial or cervical nerve lesions. Long-term results were estimated (after at least two years) based on long-term survival rate, central neurological complications (stroke,TIA) and the incidence of haemodynamically significant restenosis of the carotid artery treated by endarterectomy. RESULTS: The average time of clamming of the internal carotid artery in the eversion carotid anderectomy group was 5.36 minutes shorter than in the group treated by the conventional technique. Student's t-test showed a statistically highly significant difference in the time needed for clamming of the internal carotid artery between the two groups. The average duration of eversion endarterectomy (82 minutes) was most often 19 minutes shorter than the duration of the conventional endarterectomy (101 minutes). Student's t-test showed a statistically highly significant difference in the average length of surgeries. The distal intimal fixation was more often needed during the conventional carotid endarterectomy (34.7%) compared to eversion endarterectomy (3.9%). Chi 2-test showed a statistically highly significant difference. CONCLUSION: Eversion carotid endarectomy represents a statistically significantly shorter procedure. Distal intimal fixation demanded by this procedure is very rare, clammping of the internal carotid artery is significantly shorter, and it also has a lower rate of the early neurological complications. Based on the results of this study, as well as the opinions of other authors, it can be concluded that the eversion carotid endarterectomy has an advantage over the conventional procedure.We recommend conventional procedure only in cases when retrograde pressure indicates the use of the intraluminal shunting.

[Surgical treatment of abdominal tumours closely related to major blood vessels].

INTRODUCTION: Radical operative treatment of abdominal tumours closely related to major blood vessels often demands complex vascular procedures. OBJECTIVE: The aim of this paper was to present elementary principles and results of the complex procedures, based on 46 patients operated on at the Institute for Cardiovascular Diseases, Clinical Centre of Serbia, Belgrade, from January 1999 to July 2006. METHOD: Primary localisation of the tumour was the kidney in 14 patients, the suprarenal gland in 2, the retroperitoneum in 23 and the testis in 7 patients. Histologically, the most frequent were the following: renal carcinoma in 14 patients, teratoma in 7, liposarcoma in 5, fibrosarcoma and lymphoma in 3 patients. The tumour compressed abdominal aorta occurred in 3 cases, vena cava inferior in 5 and both the abdominal aorta and vena cava inferior in 11 cases. In 4 cases the tumour infiltrated the abdominal aorta, in 11 the vena cava inferior and in 8 both of them. In two patients, the tumour compressed the vena cava inferior and infiltrated the aorta; in two patients the aorta was compressed and the vena cava was infiltrated. In three cases only the exploration was performed due to multiple abdominal organ infiltration. The ex tempore biopsy showed the type of tumour in which the radical surgical treatment did not improve the prognosis. In 20 cases of tumour compression, subadventitional excision was performed. In 23 cases of infiltration, the tumour excision and vascular reconstruction had to be performed. Intraoperative blood cell saving and autotransfusion were applied in 27 patients. RESULTS: The lethal outcome happened in 3 (6.5%) patients during hospitalization. In other patients all reconstructed blood vessels were patent during the postoperative hospitalization period. CONCLUSION: Treatment of the abdominal tumours closely related to major blood vessels must be interdisciplinary, considering diagnostics, operability estimation and additional measures. Tumour reduction cannot improve long term prognosis, and has no major impact on life quality. There have been not many papers that analyse the long term results after such complex operations proving their appropriateness.

False anastomotic aneurysms.

This retrospective study covers the period from 1991 to 2002, during which 3,623 patients were operated on because of aneurysmal or occlusive disease of aortoiliac and femoropopliteal segments. Among them, 87 patients (2.4%) developed a false anastomotic aneurysm in the 12-year follow-up period and were treated operatively. Most frequently, in 53 patients (6.9%), a false anastomotic aneurysm developed after aortobifemoral bypass performed owing to aortoiliac occlusive disease. The cause of false anastomotic aneurysm was infection in 21 cases (24.7%); resection and revascularization were performed with a Dacron graft in 46 cases (52.9%), with a polytetrafluoroethylene graft in 10 cases (11.5%), and with the great saphenous vein in 16 cases (18.4%). Homograft implantation in 4 patients (4.6%) or extra-anatomic bypasses in 11 cases (12.6%) were performed when graft infection was suspected. Of 87 patients who underwent surgery, 74 (85.5%) had good early results without infection, reintervention, limb loss, and mortality. The presence of infection as a cause of false anastomotic aneurysm and comorbidity increased the mortality rate significantly after the reoperation, whereas the type of graft used in treatment had no influence on early results.

[Anastomotic pseudoaneurysms].

Anastomotic pseudoaneurysm is a form of false aneurysm, whose wall does not consist of all normal layers of arterial wall. Given the rising number of reconstructive vascular procedures, the increase of anastomotic pseudoaneurysm cases is expected. Therefore, identification of causes, clinical manifestations as well as factors which affect the outcome of operative treatment of anastomotic pseudoaneurysms is of great practical value. This retrospectively-prospective study included 87 surgically treated cases of anastomotic pseudoaneurysms in the period from 1991 to 2002. The most often localization of anastomotic pseudoaneurysms was the inguinal region (68-86.2%). In the majority of cases, they were caused by arterial degeneration in the anastomotic region--56 cases (65.9%) and infection--21 cases (24.7%). The most frequent manifestations of anastomotic pseudoaneurysms were bleeding due to rupture in 26 cases (29.9%) and chronic limb ischaemia in 22 cases (25.3%). An acute limb ischaemia was present in 17 cases (19.5%), the symptoms caused by local compression to the surrounding structures--in 9 cases (10.3%), and in 12 cases (13.8%), the only manifestation of anastomotic pseudoaneurysm was asymptomatic pulsatile mass. In 32 cases (36.8%), surgical treatment involved the resection of anastomotic pseudoaneurysm and graft interposition, whereas in 39 cases (44.8%), bypass procedure had to be performed after the resection. Comorbidity significantly increased mortality in the first 30 days. The use of Dacron graft in primary operation significantly improved early results of operative treatment. Absence of infection as the cause of anastomotic pseudoaneurysm is a statistically important prognostic factor of operative treatment, considering the graft patency, limb salvage, infection, need for reintervention and mortality.