Biosynthetic vascular graft: a valuable alternative to traditional replacement materials for treatment of prosthetic aortic graft infection?

BACKGROUND AND AIMS: To report the experience of a tertiary vascular surgery center using Omniflow II® biosynthetic vascular grafts for treatment of prosthetic aortic graft infection. MATERIALS AND METHODS: Retrospective analysis of all patients with prosthetic graft infections who underwent in situ aortic reconstruction using Omniflow II® grafts or other conduits between March 2015 and May 2017. Early and late mortality, perioperative complications, and reinfection rate were analyzed. RESULTS: Sixteen patients (14 males, median age 68.5, range 57-89) with prosthetic aortic graft infection were treated at our center. Eight patients received an Omniflow II® biosynthetic graft, two patients silver-triclosan coated grafts, three patients bovine pericardial tube grafts, and three patients composite bovine pericardial tube grafts with Omniflow II® graft extensions. Perioperative complications occurred in seven patients (43.8%). Early mortality rate was 18.7% (n = 3). In addition, four patients died during follow-up after a median of 11 months (range 0-34 months). We did not observe any reinfections. Bypass grafts were patent in all patients. No major limb amputations were performed during follow-up. CONCLUSION: Treatment of prosthetic aortic graft infection with Omniflow II® vascular grafts is feasible. Graft material seems to have an excellent resistance to infection and might be a valuable alternative to traditional replacement materials. Especially long-term durability has to be continuously monitored and documented.

Comparison of Long-term Outcomes of Heparin Bonded Polytetrafluoroethylene and Autologous Vein Below Knee Femoropopliteal Bypasses in Patients with Critical Limb Ischaemia.

OBJECTIVE/BACKGROUND: Endovascular first is the preferred therapy approach to critical limb ischaemia (CLI). However, in spite of new endovascular techniques, bypass surgery still plays an important role, especially in patients with complex anatomy in whom endovascular therapy is not considered feasible, or has failed. The goal of this study was to analyse the outcomes of prosthetic or autologous vein for femoropopliteal (P3) bypasses performed under the abovementioned conditions. METHODS: A retrospective analysis of patients who underwent a femoropopliteal (P3) bypass for CLI (March 2007-December 2015) was conducted. Endovascular therapy was not possible. Patency rates, limb salvage, major adverse limb event (MALE) free survival, and survival after 5 years were analysed. RESULTS: In total, 151 cases were included in the analysis (rest pain 35.8%, ulcer/gangrene 64.3%). The graft material was autologous vein in 76 cases (vein group) and heparin bonded expanded polytetrafluoroethylene (HePTFE) in 75 cases (HePTFE group). Indications, risk factors, previous revascularisation procedures, and runoff vessels were similar in both groups. Thirty day mortality was 6.6% in the vein group and 5.3% in the HePTFE group (p = .508), early graft occlusion (6.6% vs. 5.3%; p = .508) and 30 day major amputation rate (0% vs. 2.7%; p = .245) were similar between the two groups. Overall primary patency was 51.7% (55.5% [vein group] vs. 51.7% [HePTFE group]; p = .897) and overall secondary patency was 64.2% (74.6% [vein group] vs. 55.6% [HePTFE group]; p = .119), all without significance after 5 years. However, limb salvage (79.1%) was significantly different (90.0% [vein group] vs. 62.9% [HePTFE group]; p = .021). Survival was similar between the groups (47.3% vs. 42.9%; p = .582) as well as MALE free survival (69.4% vs. 55.0%; p = .348). CONCLUSION: Bypasses to the below knee popliteal artery show good results in patients with CLI unsuitable for endovascular therapy. Vein is still the first line graft material.

Restenosis after Carotid Interventions and Its Relationship with Recurrent Ipsilateral Stroke: A Systematic Review and Meta-analysis.

OBJECTIVE: Do asymptomatic restenoses > 70% after carotid endarterectomy (CEA) and carotid stenting (CAS) increase the risk of late ipsilateral stroke? METHODS: Systematic review identified 11 randomised controlled trials (RCTs) reporting rates of restenosis > 70% (and/or occlusion) in patients who had undergone CEA/CAS for the treatment of primary atherosclerotic disease, and nine RCTs reported late ipsilateral stroke rates. Proportional meta-analyses and odds ratios (OR) at end of follow-up were performed. RESULTS: The weighted incidence of restenosis > 70% was 5.8% after "any" CEA, median 47 months (11 RCTs; 4249 patients); 4.1% after patched CEA, median 32 months (5 RCTs; 1078 patients), and 10% after CAS, median 62 months (5 RCTs; 2716 patients). In four RCTs (1964 patients), one of 125 (0.8%) with restenosis > 70% (or occlusion) after CAS suffered late ipsilateral stroke over a median 50 months, compared with 37 of 1839 (2.0%) in CAS patients with no significant restenosis (OR 0.87; 95% CI 0.24-3.21; p = .8339). In seven RCTs (2810 patients), 13 out of 141 (9.2%) with restenosis > 70% (or occlusion) after CEA suffered late ipsilateral stroke over a median 37 months, compared with 33 out of 2669 (1.2%) in patients with no significant restenoses (OR 9.02; 95% CI 4.70-17.28; p < .0001). Following data correction to exclude patients whose surveillance scan showed no evidence of restenosis > 70% before stroke onset, the prevalence of stroke ipsilateral to an untreated asymptomatic > 70% restenosis was seven out of 135 (5.2%) versus 40 out of 2704 (1.5%) in CEA patients with no significant restenosis (OR 4.77; 95% CI 2.29-9.92). CONCLUSIONS: CAS patients with untreated asymptomatic > 70% restenosis had an extremely low rate of late ipsilateral stroke (0.8% over 50 months). CEA patients with untreated, asymptomatic > 70% restenosis had a significantly higher risk of late ipsilateral stroke (compared with patients with no restenosis), but this was only 5% at 37 months. Overall, 97% of all late ipsilateral strokes after CAS and 85% after CEA occurred in patients without evidence of significant restenosis or occlusion.

A comparison of tibial and peroneal venous and HePTFE bypasses in diabetics with critical limb ischemia.

OBJECTIVE: In this study we analyzed the outcome of tibial and peroneal venous and heparin-bonded expanded polytetrafluoroethylene (HePTFE) bypasses in diabetics with critical limb ischemia (CLI). We aimed to verify our hypothesis that HePTFE grafts will achieve acceptable 1-year patency and limb salvage results in patients who lack an adequate vein. METHODS: We conducted a retrospective analysis for all diabetics who underwent tibial bypass surgery in our department between October 2007 and October 2012. The study includes 97 grafts. All these patients were not suited for an endovascular therapy. We used autologous veins in 56 cases (Vein-Group) and HePTFE grafts in 41 cases (HePTFE-Group). Study endpoints were primary and secondary patency, limb salvage, and survival at 2 years postoperatively. RESULTS: Risk factors and indications were similar in both groups. The comparison between HePTFE- and Vein-Group showed significantly different patency rates. At 2 years, primary patency was 39.3% in HePTFE-Group vs. 78.5% in Vein-Group (P = .003) and secondary patency was 47.4% vs. 81.9% (P = .002). Limb salvage at 2 years was 79.3% vs. 87.4% (P = .073) and survival was 64.6% vs. 62.9% (P = .593) at the 2-year mark, with no significant differences. 30-days mortality, graft occlusion and major amputation rate showed no significant differences, either. CONCLUSIONS: This study shows that HePTFE bypasses are a viable option for diabetics undergoing tibial bypass surgery when no adequate vein is available.

Xenografts in septic vascular surgery.

BACKGROUND: In general, autologous veins are the optimal replacement material for an infected vascular graft in terms of handling, durability and resistance to reinfection. In the absence of suitable autologous material, several options are available, each of which has specific advantages and drawbacks with regard to these characteristics. METHODS: In recent years, xenogeneic materials (in particular pericardial patches from different species and biosynthetic grafts) have been increasingly used as replacement material in the setting of infections. Bovine and equine pericardial patches are applied in particular as self-made tube grafts in the aortic region and also in infections of iliacofemoral prosthetic grafts and shunt infections. RESULTS: The results of small clinical series on durability and resistance to reinfection are promising. CONCLUSION: It is feasible to use biosynthetic materials to replace infected intracavitary and extracavitary vascular grafts with remarkably low reinfection rates; however, the unique mechanical properties of the grafts as well as the initially increased thrombogenicity, need to be taken into consideration.

The endovascular performance spectrum of vascular surgery departments in Germany: Results of an online survey among senior department physicians.

AIM: To survey the scope of vascular surgery services in Germany. METHOD: A total of 308 senior German vascular surgeons received a 19-point questionnaire pertaining to department structure and scope of services. Of these surgeons 223 replied between 16 August 2015 and 23 October 2015 (response rate 72 %), with 62.2 % reporting an additional qualification as an endovascular surgeon according to the guidelines of the German Society for Vascular Surgery and Vascular Medicine (Deutsche Gesellschaft für Gefäßchirurgie und Gefäßmedizin, DGG) and 43.5 % as a DGG® endovascular specialist. RESULTS: The number of respondents fully authorized to train in vascular surgery was 71.3 %, while 28.3 % were authorized for limited training. Authorization as a DGG® endovascular surgeon was reported by 24.2 % and authorization as a DGG® endovascular specialist by 17 % of respondents. All respondents performed endovascular interventions on pelvic vessels and 99.1 % also reported carrying out femoral and popliteal endovascular interventions. Endovascular procedures in crural vessels were carried out by 90.1 % and 93.7 % of vascular surgeons performed endovascular procedures in the region of the abdominal aorta (segment V), arteriovenous (AV) fistulas and shunts (85.2 %), upper extremity vessels (80.3 %), the thoracic aorta (segment III, 68.2 %), renal arteries (62.8 %) and visceral aorta (segment IV, 60.5 %). In all 43.5 % of respondents reported experience with endovascular procedures on the carotid bifurcation. Percutaneous arterial procedures formed the focus of endovascular activity, totalling on average 259 interventions per year and department, followed by diagnostic angiography (without intervention) at 166 procedures per year and hybrid arterial interventions at 141 interventions per year. CONCLUSION: This survey revealed a high level of endovascular expertise among vascular surgeons in Germany. This applies not only to the scope of endovascular activities in diagnosis and treatment but also to the number of estimated annual procedures.

The impact of infrainguinal endovascular interventions on the results of subsequent femoro-tibial bypass procedures: a retrospective cohort study.

BACKGROUND: Endovascular recanalization has become the accepted first-line treatment strategy for most lower extremity arterial occlusions, especially in patients with critical limb ischemia (Rutherford 4-6). Prior endovascular interventions have been described as risk factors for the outcome of subsequent lower extremity bypass surgery. The effect on subsequent tibial and peroneal bypasses is controversial. We analyzed the impact of prior endovascular lower extremity revascularization procedures on the short- and mid-term results of femoro-tibial and femoro-peroneal bypasses. METHODS: A retrospective analysis was conducted of all patients who had undergone tibial or peroneal bypass surgery after prior endovascular interventions (PEI-Group, n=40) of the same extremity in our department from October 2007 to October 2012. We compared this group with a group of patients who had received a tibial or peroneal bypass as primary revascularization procedure (BF-Group, n=93) during the same period of time because primary endovascular therapy had been deemed unfeasible in those cases. Indication in all cases was critical limb ischemia; the median age was 78 years (range 50-90 years), 45.1% were diabetics, and 42.9% were female. The graft material was autologous vein in 80 cases and HePTFE in 53 cases. Endpoints of the analysis were primary and secondary patency rates, limb salvage and survival at 2 years postoperatively. RESULTS: At 2 years overall primary patency was 68.4%, secondary patency was 69.5%, limb salvage was 83.6% and survival was 62.6%. Primary patency for the BF-Group was 74.3% vs. 55.1% for the PEI-Group (P=.310) at 2 years; secondary patency was 74.6% vs. 59.1% (P=.268). Prior endovascular intervention did not have any significant effects on limb salvage (83.7% vs. 83.6%; P=.470) or survival rates (61.0% vs. 65.0%; P=.258) at the 2-year mark, either. There were no significant differences in graft occlusion, death and major amputation rates within the first 30 postoperative days. Except for male gender, there were no significant differences in risk factors and indications between the two groups. CONCLUSIONS: Prior endovascular intervention of femoro-tibial vessels does not have a negative impact on the outcome of subsequent tibial or peroneal bypass surgery in patients with critical limb ischemia.

[Hybrid operation theatre in vascular surgery. Options and perspectives]. / Hybridoperationssaal in der Gefäßchirurgie. Möglichkeiten und Perspektiven.

BACKGROUND: Demographic development leads to an increase in vascular interventions due to the increase in elderly and multimorbid patients. The aim of this study was to demonstrate the open interventional therapy options and their influence on staff and patients which have become possible due to the introduction of angio-hybrid operations including 3-D imaging Dyna-CT. MATERIAL AND METHODS: The modifications with respect to radiation protection for staff, improvements for patients and the possibilities of operative 3-D imaging Dyna-CT are described based on the current literature. RESULTS: The implementation of angio-hybrid operation theaters has resulted in new open interventional treatment options which can also be employed for high risk elderly patients with aortic and peripheral arterial pathologies. With hybrid operations the radiation exposure and contrast medium exposure can be reduced for patients and an improvement in the results can also be achieved. The implementation of 3-D imaging in the angio-hybrid operation theater could also lead to further improvements, especially for complex aortic procedures. DISCUSSION: Using angio-hybrid operational procedures complex interventions can be carried out with more safety for patients and personnel. The implementation of 3-D imaging Dyna-CT offers additional interesting options for complex aortic procedures.

Current status of Hemobahn/Viabahn endografts for treatment of popliteal aneurysms.

The aim of the present study was to review the literature reporting the use of the Hemobahn/Viabahn endograft (W. L. Gore and Assoc Inc., Flagstaff, AZ, USA) for endovascular treatment of popliteal artery aneurysms (PAA). A PubMed database search was performed looking for studies reporting endovascular treatment of PAA with the Hemobahn/Viabahn endograft within the period January 2000-December 2012. All relevant studies were independently assessed and all references were examined for potentially missed relevant reports. Studies were included if they reported experience with five patients or more. Eight studies with 222 patients (mean age 72.4 years, 92.3% male) and 251 PAA (mean diameter 2.9 mm, 14.3% symptomatic) were included. Thirteen cases (5.2%) were treated on an urgent basis, including three cases of ruptured PAA and 10 cases of acute limb ischemia. Initial technical success was 99.2%. The mean number of implanted endografts/PAA was 1.8 (range 1-4). Thirty-day mortality was 1 (0.4%) patient. Perioperative complications occurred in 1.6%, consisting of three access site hematomas and one acute endograft thrombosis. Cumulative mean follow-up duration was 36.9 months. During this period, a total of 46 endograft failures (42 occlusions, 4 stenoses) were observed within a mean postoperative time interval of 10.8 months. Cumulative primary and secondary patency rates were 85.6% and 93.4% at one year, and 78.5% and 90.4% at 2 years, respectively. Limb salvage rate during follow-up was 99.2%. Endoleak was noticed in 15 (6%) cases and endograft migration in 13 (5.2%) cases. Endograft fracture was reported in 14 (5.6%) cases, resulting in occlusion in six patients, and in type III and IV endoleaks in two patients. Secondary intervention during follow-up was required in 47 (18.7%) cases, including 32 reinterventions for endograft occlusion, four for endograft stenosis, and 11 for endoleak repair. Endovascular PAA repair with the Hemobahn/Viabahn endograft is feasible and safe yielding excellent initial technical success rates, minimum perioperative mortality and morbidity, and mid-term patency and limb salvage rates comparable to open surgery. These results suggest that a significant proportion of patients might benefit from endovascular PAA repair.

[Hybrid operating rooms: only for advanced endovascular procedures?]. / Angio-Hybrid-Operationsraum: Grundvoraussetzung nur für komplexe endovaskuläre Eingriffe?

The evolution of endovascular techniques has led to the concept of the "hybrid operating room" (hybrid OR). A hybrid OR combines the sterility of an OR in an operating theatre environment with a high-quality fixed imaging system. On the basis of these advantages it would be desirable that an angio-hybrid OR becomes a standard requirement for endovascular surgery. In Great Britain guidelines have already been published that require a hybrid OR even for normal endovascular management of the infrarenal aorta. However, in Germany there are no guidelines from professional societies or formal rules from the federal joint committee, thus in this article a classification of endovascular procedures according to their complexity and the necessary infrastructures are proposed in order to define particular procedures that should only be performed in an angio-hybrid OR. According to our experience, endovascular procedures can be classified into four categories based on their complexity and the requirements regarding fluoroscopy: level 1: standard EVAR, TEVAR, iliac and popliteal artery procedures; level 2: iliac branched (IBD) and standard (2 fenestrations for the renal arteries and a scallop for the superior mesenteric artery) fenestrated stent-grafting; level 3: more complex fenestrated procedures (three or four fenestrations); and level 4: branched stent-grafting for TAAA. At this moment it is still acceptable to perform level 1 and level 2 procedures outside of a hybrid OR. In our opinion, it is not recommended to perform level 3 and level 4 endovascular procedures without a hybrid OR.

Necrosis of the leg after intraarterial drug injection.

Inadvertent intraarterial injections in the context of drug abuse can cause damage to the vascular system. The clinical picture depends on the drug properties and ranges from partial ischemia to necrosis of the affected extremity. There are no current evidence-based guidelines regarding the management of intraarterial drug injections. In many cases the concept of solving vasospasm after injection is based on the use of intraarterial application of prostaglandins. We report a case in which a mixture of drugs was injected into the left femoral artery. The patient arrived 24 hours later with ischemia of the left leg at our emergency department. Angiography showed that there was no blood flowing in the leg. Despite intraarterial application of vasodilatators, regional neurolysis and thrombolyis with urokinase major amputation was unavoidable. The outcome after inadvertent injection depends on certain drug properties and the delay between injection and the beginning of therapy.

VEGF: a surrogate marker for peripheral vascular disease.

This study aims to evaluate the value of VEGF as a surrogate marker for peripheral vascular disease (PVD). Prior to treatment, serum VEGF levels were evaluated by enzyme-linked immunosorbent assay (ELISA) in 293 PVD patients. Risk factors and clinical parameters of PVD were documented. Twenty-six age-matched healthy volunteers served as controls. Serum VEGF values strongly correlated with Fontaine stages (p<0.006, stage IV vs. controls). High VEGF values prior to treatment were associated with poor outcome. Serum VEGF appears to indicate the severity of PVD and might serve as a surrogate indicator of disease severity.

Retrojugular versus ventrojugular approach to carotid bifurcation for eversion endarterectomy: a prospective randomized trial.

OBJECTIVES: The aim of this prospective randomized study was to demonstrate the comparability of retrojugular access for carotid eversion endarterectomy compared to the conventional ventrojugular procedure. PATIENTS AND METHODS: Due to the expected minor and major complication rate of 5% in patients undergoing carotid surgery, a patient cohort of 600 study patients was planned. All patients underwent standard preoperative and postoperative assessment including clinical investigation and fiberoptic laryngoscopy. The 6 month follow-up examination included an evaluation of patient contentment, a duplex scan, clinical investigation and a fiberoptic laryngoscopy. RESULTS: After the first interim evaluation of 101 patients, the study was stopped because of a significant increase in temporary ipsilateral vocal cord motility dysfunction in the retrojugular access group (31% vs. 6%, p=0.0014). This early postoperative impairment was, however, not statistically significant at the follow-up examination at 6 months (2.4% vs. 0%). No other significant differences concerning major complications (death or stroke), other cranial nerve injuries, wound healing, or patient satisfaction was observed neither in the early postoperative phase nor at follow up. CONCLUSION: Due to the high incidence of temporary ipsilateral vocal cord dysfunction in patients undergoing retrojugular exposure of the carotid artery, we recommend the conventional ventrojugular approach, which can be performed by incision along the anterior border of the sternomastoid muscle or by transversal skin incision.

Early experience shows rapid shrinking of abdominal aortic aneurysms after endovascular treatment with Anaconda device.

BACKGROUND: The Anaconda prosthesis is a new endovascular device for abdominal aortic aneurysms repair. AIM: of the study was to evaluate successful access to the arterial site, safety and efficacy of stent placement and fixation, assessment of endoleaks, patency of the graft due to twists, kinks or obstruction within the first 30 days after the procedure. Secondary objectives were the assessment of clinical success after 6 months due to graft patency and aneurysm exclusion without endoleak as well as the continuing clinical success without showing aneurysm expansion or any graft failure. PATIENTS AND METHODS: Between 2003 and 2006 a total of 14 patients with infrarenal aortic aneurysm (median diameter prior to endovascular treatment: 56.7 mm (range: 50 to 70 mm) were treated with the Anaconda endovascular device. 8 of these patients were treated in accordance to a prospective Phase II clinical study protocol (Anaconda ANA 004). 6 more patients received the same endovascular device after CE-certification. RESULTS: Primary and secondary objectives were achieved in 12 of 14 patients after 6 months. In one patient insertion of the graft system was impossible due to kinking and circular calcification of the iliac arteries. Iliac access utilizing an alternative stent graft system (Cook, Zenith) was also unsuccessful. This patient underwent a conversion to open surgery and died. Another patient died 6 months after treatment unrelated to the procedure. A significant reduction of the median aneurysm diameter from 56.7 to 49.0 mm (range: 45 to 54 mm) was achieved after 6 months (p = 0.05). No endoleak was seen in the follow up. CONCLUSIONS: Early results show that he Anaconda endovascular device for aneurysm repair is a safe and effective device for patients with suitable abdominal aortic aneurysms and proper distal access vessels which results in significant aneurysm diameter decrease and a low complication rate after 6 months of follow-up.

[Diagnosis and endovascular treatment of proximal endograft instability after thoracic endografting]. / Diagnostik und endovaskuläre Behandlung einer proximalen Endograft-Instabilität nach thorakalem Endostent.

Four cases of proximal endostent instability after endovascular tube graft treatment of thoracic aortic disease using the TAG Gore system are reported. This potentially hazardous complication is characterized by a lack of attachment of the device to the small curvature of the aortic arch. Towering up against the hemodynamic forces in this area, the endograft could collapse and occlude the aorta. To identify this complication we recommend to perform an early postinterventional CT-scan with parasagittal reconstruction and an observation of the proximal endograft by fluorography. Endovascular solutions for the treatment of this complication may be either a proximal extension by another endograft or fixation of the proximal endograft by a balloon expandable Palmaz stent.

Thermoablation of colorectal liver metastases promotes proliferation of residual intrahepatic neoplastic cells.

BACKGROUND: Resection of liver neoplasms is believed to promote growth of residual intrahepatic neoplastic cells. As the effects of radiofrequency thermoablation (RFA) are still unknown, we aimed to compare the influence of RFA versus liver resection on residual intrahepatic neoplastic cells. METHODS: A primary metastasis was established by injection of syngenic CT-26 coloncarcinoma cells into the right liver lobe of Balb/C mice. Five days later, 3 x 10(5) GFP-transfected CT-26 tumor cells were injected intraportally, and the primary metastasis was treated by resection (group I, n = 7) or RFA (group II, n = 7). The effect of resection/RFA on the growth of single intrahepatic GFP neoplastic cells was evaluated by intravital microscopy 7 days later. RESULTS: Resection of a primary metastasis enhanced the proliferation of residual intrahepatic neoplastic cells, compared with the control group. RFA led to an increased survival of residual neoplastic cells (5% +/- 2% vs 1% +/- 1% single cells) and significantly promoted the proliferation of neoplastic cells, compared with resection (13% +/- 4% vs 2% +/- 2% micrometastases). CONCLUSIONS: RFA strongly promotes intrahepatic growth of residual neoplastic cells. On the basis of our findings, RFA should not be recommended as an alternative curative treatment to resection. Furthermore, if RFA is performed as palliative therapy, postinterventional chemotherapy may be advisable to overcome the stimulation of residual neoplastic cells by RFA.

Preferential migration of CD62L cells into the appendix in mice with experimental chronic colitis.

BACKGROUND: Clinical and experimental studies suggest that appendectomy can protect against development of ulcerative colitis and Crohn's disease. However, how T cells in the appendix affect the development of colitis has not been clarified. AIM: To investigate the in vivo migration and activation of colitis-inducing CD62L+ cells during development of chronic colitis. METHODS: CD62L+CD4+ cells were fluorescently labeled and transferred to severe combined immunodeficient (SCID) mice to induce colitis. In vivo migration of T cells into the mucosa of the appendix and colon was quantified by in vivo microscopy after 7 weeks. In a second experiment, unlabeled CD62L+CD4+ cells were transferred, reisolated after 7 weeks, and adhesion molecule (integrin alpha4beta7) and costimulatory molecule (CD154) expression was analyzed. RESULTS: Six to eight weeks after CD62L+CD4+ cell transfer, SCID mice developed chronic colitis. In vivo microscopic analysis demonstrated a preferential migration of fluorescence-labeled CD62L+CD4+ cells into the mucosa of the appendix versus the colon. Re-isolation of lamina propria cells from mice with colitis confirmed that CD62L+CD4+ cell migration was significantly enhanced in the appendix, compared to the colon (3.5-fold). Furthermore, a higher proportion of CD62L+CD4+ cells re-isolated from the appendix expressed integrin alpha4beta7 and CD154 than from the colon. CONCLUSION: This study demonstrates the preferential migration of CD62L+CD4+ cells into the appendix as compared to the colon. This migration pattern correlated with upregulation of integrin alpha4beta7 and CD154 (CD40 ligand) on T cells. Our results suggest an important role of the appendix in the pathogenesis of colitis.

[Popliteal vein entrapment in patients with unspecific symptoms of venous insufficiency]. / Belastungs- oder lageabhängige Schwellung der Wadenmuskulatur mit Spannungsgefühl und krampfartigen Schmerzen.

Popliteal vein entrapment must be taken in consideration in patients with symptoms of venous insufficiency. Leg edema, swelling, calf pain, and muscle cramps are all unspecific signs. Most patients thus far have presented with deep vein thrombosis or chronic venous insufficiency. Popliteal entrapment syndrome must be taken into account in younger patients in whom predisposing factors are absent and chronic calf swelling is notable. Diagnosis is easily confirmed by noninvasive stress testing with duplex imaging and pencil Doppler probe placed over the posterior tibial artery. Additionally, digital subtraction angiography with the foot in neutral and dorsi plantarflexion is recommended for arterial entrapment. Surgery is advisable for treatment and can be done without significant morbidity. In asymptomatic patients, we suggest using the term "popliteal vein entrapment phenomenon." We describe different etiologies of popliteal vein entrapment in three cases and present a review of the literature.