[Surgical therapy of peripheral arterial occlusive disease]. / Zur operativen Therapie der peripheren arteriellen Verschlusskrankheit.

The surgical treatment of peripheral arterial occlusive disease focuses not only on the direct restoration of the femoral bifurcation but also on the peripheral bypass, especially in the case of chronic amputation-threatening ischemia. Comprehensive imaging is indispensable for planning surgical therapy. The local reconstruction of the femoral bifurcation offers very good long-term results and can be easily combined with endovascular methods. The peripheral bypass is the central pillar of surgical therapy, especially in CLTI. Autologous vein should always be the first-choice material. It delivers good long-term results in every position. Prosthetic material is only used if there is no vein and should be combined with autologous veins in the crural and pedal area if possible. The technical limit for a bypass system lies in the pedal arteries and their branches. These methods can be combined with upstream and downstream endovascular interventions in the form of a hybrid intervention. Surgical and endovascular interventions are to be considered as complementary.

Long-Term Results of Femorodistal Sequential Composite-Bypass Combining Heparin-Bonded PTFE-Prosthesis and Autologous Vein Using the Deutsch Bridge Technique in Critical Limb-Threatening Ischemia.

BACKGROUND: Autologous vein bypass provides excellent long-term results in critical limb-threatening ischemia (CLTI), but a substantial portion of patients have insufficient vein length. In limbs with two distal outflow vessels and limited vein length, a vascular prosthesis may be combined with autologous vein for a sequential composite bridge bypass (SCBB). Results regarding graft function, limb salvage and reinterventions are presented. METHODS: Between January 2010 and December 2019, 47 consecutive SCBB operations with a heparin-bonded PTFE-prosthesis and autologous vein were performed. Grafts were followed with a duplex scan with prospective documentation in a computerized vascular database. Retrospective analysis of graft patency, limb salvage and patient survival was performed. RESULTS: Mean follow-up was 34 months (range 1-127 months). 30-day mortality was 10.6% and 5-year patient survival 32%. Postoperative bypass occlusion occurred in 6.4% and late occlusions or graft stenoses in 30%. Two prostheses developed late infection and seven legs were amputated. Primary, primary assisted, secondary patency and limb salvage rate were 54%, 63%, 66% and 85% after 5 years, respectively. CONCLUSIONS: SCBB patency and limb salvage were good despite a high early postoperative mortality. Combination of a heparin-bonded PTFE-prosthesis and autologous vein appears to be a valuable tool in CLTI in case of insufficient vein.

Contemporary results with the biosynthetic glutaraldehyde denatured ovine collagen graft (Omniflow II) in femoropopliteal position.

OBJECTIVE: The objective of this study was to analyze the outcome of a contemporary series of femoropopliteal bypass operations with the glutaraldehyde denatured polyester mesh-reinforced ovine collagen prosthesis (OCP; Omniflow II [LeMaitre Vascular, Inc, Burlington, Mass]). The experience of two tertiary centers regarding long-term graft function, secondary reinterventions, and biodegeneration of the OCP prosthesis is presented. METHODS: Between January 2006 and January 2014, a series of 205 consecutive operations with the OCP in the femoropopliteal position (54 above knee and 151 below knee) were performed in 194 patients in 202 limbs for disabling claudication (72), chronic critical ischemia (105), acute ischemia (18), popliteal artery aneurysm (4), degeneration of a venous or prosthetic graft (5), and infection of a synthetic bypass graft (1). Grafts were observed with duplex ultrasound scan supplemented by additional angiography in case of recurrent ischemia with prospective documentation of follow-up data in a computerized vascular database. Retrospective analysis of graft patency, limb salvage, and diagnosis of aneurysmal graft degeneration was performed. RESULTS: The 30-day mortality was 3.9%. Early thrombotic bypass occlusion occurred in 8.2% of cases. Four early graft infections could be successfully managed by local treatment with graft preservation. After a mean (median) follow-up of 56 (55) months (range, 1-135 months), primary patency, primary assisted patency, secondary patency, and limb salvage were 71%, 78%, 78%, and 91% for above-knee bypass and 40%, 50%, 63%, and 87% for below-knee bypass at 5 years. Biodegeneration in the form of graft aneurysm or graft stenosis was detected in 26 grafts (12.6%), resulting in secondary open or endovascular procedures in 16 cases. CONCLUSIONS: The OCP provides satisfactory medium- and long-term patency and limb salvage in the femoropopliteal position. Aneurysmal degeneration or graft stenosis may develop over time, demanding lifelong duplex ultrasound surveillance and secondary intervention if needed. Its possible infection-resistant behavior in a contaminated field combined with an acceptable graft patency and limb salvage justifies the use of this graft in the absence of autologous vein.

External polytetrafluoroethylene reinforcement of varicose autologous vein grafts in peripheral bypass surgery produces durable bypass function.

OBJECTIVE: Use of autologous veins as peripheral bypass graft may become critical in the presence of significant varicose degeneration of the harvested vein. External support of such dilated veins with standard polytetrafluoroethylene (PTFE) prostheses was recommended as an option to use these veins for peripheral bypass. A single-center experience with this technique regarding long-term graft function, secondary reinterventions, and potential graft degeneration is presented. METHODS: Between January 1995 and January 2006, there were 54 patients with varicose veins who underwent 57 consecutive infrainguinal vein bypass operations with PTFE reinforcement in 57 limbs. Indications for surgery consisted of disabling claudication (5), chronic critical ischemia (40), popliteal aneurysm (11), and acute ischemia (1). Grafts were observed with duplex ultrasound scan supplemented by additional angiography in case of recurrent ischemia, with prospective documentation of follow-up data in a computerized vascular database. Graft patency, limb salvage, and possible degeneration of the vein grafts were retrospectively analyzed. RESULTS: Mean follow-up was 79 months (range, 1-219 months). The 30-day mortality was 2%. Secondary procedures to maintain or to restore bypass patency were necessary in 12 grafts (21%). Primary, primary assisted, and secondary patency rates were 54%, 73%, and 73% after 5 years for all bypasses, with a limb salvage rate for limbs operated on for chronic critical or acute ischemia of 83%. Significant stenosis of a reinforced vein segment was detected in one case after 56 months, with subsequent replacement of the vein graft with a biologic vascular prosthesis. CONCLUSIONS: Good late graft patency and limb salvage combined with a low rate of late vein graft degeneration justify the use of external PTFE reinforcement of varicose vein segments in infrainguinal bypass surgery.

Very distal vein bypass in patients with thromboangiitis obliterans.

BACKGROUND: Surgical revascularization for chronic critical limb ischaemia in patients with thromboangiitis obliterans (TAO) still remains controversial. Generally, besides cessation of smoking, conservative treatment supported by intravenous administration of vasoactive agents is regarded as the treatment of choice, in combination with local wound therapy or minor amputation. PATIENTS AND METHODS: In four male patients (42-47 years) surgical revascularization was chosen as therapy for established gangrene or non-healing ulceration after unsuccessful conservative treatment and cessation of smoking. Angiography was able to identify a suitable distal arterial segment for the bypass which was revascularized by means of an autologous vein graft. Grafts were followed with repetitive duplex ultrasound. Revision of the bypass graft was initiated if indicated by pathological duplex findings. RESULTS: In all cases a bypass could be constructed with either the ipsilateral greater saphenous vein or arm veins. A distal origin configuration was possible in three cases with popliteo-pedal or cruro-pedal bypasses. In the fourth case the distal superficial femoral artery was used for inflow. Two early graft thromboses underwent successful revision. During follow-up, duplex ultrasound identified graft stenoses in three bypasses which were successfully treated with endovascular techniques. All grafts are patent with complete resolution of ischaemic symptoms after 46, 42, 32, and 29 months. The patients remained non-smokers and returned to a professional life. CONCLUSIONS: Surgical therapy with distal vein bypass for persistent ischaemic symptoms after definitive cessation of smoking seems feasible in selected cases with TAO and a suitable distal artery. Close follow-ups of the patients with duplex ultrasound are necessary to identify developing vein graft stenoses. Angioplasty seems to be an important part of the long-term therapeutic concept.

Patency of renal and visceral vessels after open thoracoabdominal aortic replacement.

OBJECTIVE: In thoracoabdominal aortic aneurysms (TAAAs), a paradigm shift is observed from open surgery toward total endovascular aortic repair using fenestrated and branched endografts. Whereas outcome after open replacement in terms of mortality and paraplegia has been evaluated extensively, no studies exist addressing long-term patency of visceral and renal vessels. To enable comparison of target vessel patency between open and endovascular treatment, we analyzed our series of open TAAA replacements. METHODS: Our vascular surgery database was screened for patients who received open TAAA replacement between 1998 and 2012, and patient records were analyzed retrospectively. All available imaging scans (computed tomography and magnetic resonance angiography: preoperative, postoperative, and follow-up) were evaluated for graft and vessel patency. RESULTS: We identified 62 patients (mean age, 66 ± 10 years; 40 men) who had been operated on for aneurysms of Crawford types I (8), II (13), III (13), and IV (24) and Safi type V (4). A total of 181 vessels were revascularized by either patch inclusion (n = 147) or selective revascularization (bypass or transposition, n = 34); 48 survived the procedure, resulting in a number of vessels available for follow-up of 154 (patch, 126; selective revascularization, 28). The respective patency rates for overall, patch, and selective revascularization were 95.2%, 94.2%, and 100% at 5 years and 83.7%, 81.3%, and 100% at 10 years, respectively. In addition, a trend for better performance of selective revascularization (bypass or transposition) was evident as all vessel occlusions were observed in cases of patch inclusion, whereas all selectively revascularized vessels were patent. The respective patency rates for the celiac trunk, superior mesenteric artery, and left and right renal artery were 100%, 97.5%, 92.3%, and 90.3% at 5 years. CONCLUSIONS: In our series of open thoracoabdominal aortic replacement, excellent patency rates for revascularized renal and visceral vessels were observed during long-term follow-up. We were able to provide a reference value of long-term target vessel patency that can and should be taken into account to judge the efficacy of endovascular repair in TAAA.

Outcomes of complex femorodistal sequential autologous vein and biologic prosthesis composite bypass grafts.

OBJECTIVE: Femorodistal autologous vein bypass proves to be the preferred surgical therapy for long arterial occlusions and provides excellent early and long-term results in critical lower limb ischemia. Whenever vein length was insufficient and two distal outflow arteries were present, a sequential composite bypass configuration was chosen with human umbilical vein (HUV) or ovine collagen prosthesis (Omniflow II; Bio Nova International Pty Ltd, North Melbourne, Australia) as the proximal prosthetic part of the bypass. Single-center experience with this technique regarding limb salvage, graft function, secondary reinterventions, and biodegeneration is presented. METHODS: Between January 1998 and January 2009, 122 consecutive sequential composite bypass operations were performed on 116 patients for short-distance claudication (2), chronic critical ischemia (117), or acute ischemia (3) in the absence of sufficient autologous vein length. HUV was used in 90 cases and Omniflow II in 32 cases. Grafts were followed by duplex scan supplemented by angiography in case of recurrent ischemia with prospective documentation of follow-up data in a computerized vascular database. Retrospective analysis of graft patency, limb salvage, and aneurysmal degeneration of the biologic prosthesis was performed. RESULTS: Mean follow-up was 59 ± 45.5 months (range, 1-161 months). The 30-day mortality was 4.1%. Early postoperative complete or partial bypass thrombosis developed in 16% (20 cases) and required successful revision in 16 cases. During follow-up, 30 complete and 12 partial bypass occlusions occurred, necessitating selective surgical or interventional revision. Primary, primary assisted, and secondary patency rates and the limb salvage rate were 48%, 62%, 71%, and 87%, respectively, after 5 years and 26%, 46%, 54%, and 77%, respectively, after 10 years for all bypasses. Late biodegeneration of HUV prostheses was detected in four instances. CONCLUSIONS: Late graft patency and limb salvage were good. These factors, combined with a tolerable rate of late aneurysmal degeneration, justify the use of biologic vascular conduits and autologous vein for complex femorodistal reconstructions.

Durability of open popliteal artery aneurysm repair.

OBJECTIVE: The objective of this study was to analyze our long-term results after open surgery for popliteal artery aneurysm. METHODS: Records of patients who received surgery between 1998 and 2010 were retrieved from a computerized database and analyzed retrospectively. End points of the study were perioperative mortality and morbidity and patency and limb salvage rate. RESULTS: Two hundred and six popliteal aneurysms (median diameter, 30 mm; interquartile range, 18 mm) were treated (161 elective, 45 emergent) in 154 patients (mean age, 67 ± 11 years) using vein grafts (82%) via the medial approach (92%). Above-knee popliteal artery (45%) and below-knee popliteal artery (65%) were the predominant inflow and outflow vessels. The overall surgical mortality was 2% (2% for elective and 3% for emergent procedures; P = not significant). Primary, assisted primary, and secondary patency rates were 88.1% (73.5%), 92.1% (84.3%), and 96.5% (89.8%) at 5 (at 10) years, respectively, with no significant difference between elective and emergent surgeries. Limb salvage rate was significantly reduced in the emergent group vs the elective group with 91.1% vs 98.6% at 5 and 10 years (P = .0049). The rate of freedom from any reintervention was 84.3% at 5 and 69.8% at 10 years, respectively. CONCLUSIONS: Open surgery for popliteal artery aneurysm is marked by low perioperative mortality and morbidity and provides excellent long-term results.

Use and durability of femoral vein for autologous reconstruction with infection of the aortoiliofemoral axis.

OBJECTIVE: To analyze early and late mortality, venous morbidity, reinfection, and freedom from reintervention after using the femoral vein (FV) for vascular reconstruction with infection of the aortoiliofemoral axis. METHODS: By reviewing our database, 86 patients could be identified with implantation of FV grafts in infected fields between November 1995 and July 2012. The patient records were retrospectively analyzed and follow-up information obtained from patients or their general physician. Seventy-one patients presented with prosthetic graft infection and 15 with an infected aneurysm. For data analysis, patients were divided into an aortoiliac (n = 67) and a femoral group (n = 19). Study end points assessed were early and late mortality, incidence of deep vein thrombosis of the FV donor limb, graft patency, limb salvage, reinfection, and freedom from reintervention. RESULTS: Sixty-seven aortoiliac reconstructions were performed using 84 FV grafts with an operative mortality of 9%. After a mean follow-up of 45 months, survival, patency, limb salvage, and freedom from reintervention were 45%, 97%, 94%, and 91%, respectively, at 5 years. Twenty FV grafts were employed for 19 femoral reconstructions with an operative mortality of 10.5%. Here, mean follow-up was 35 months and survival, patency, limb salvage, and freedom from reintervention were 29%, 87%, 93%, and 81%, respectively, at 5 years. Specimen culture confirmed Staphylococcus (epidermidis and aureus) as the predominant microorganism. Venous morbidity after FV harvest showed an incidence of deep venous thrombosis of 13.7% for popliteal and 10.6% for tibial level at a follow-up of 24 months with only mild clinical symptoms (21% limb swelling). CONCLUSIONS: Vascular reconstruction using autologous FV in arterial and graft infection of the aortoiliofemoral axis provides durable long-term results with acceptable mortality and morbidity.

Minimum cause--maximum effect: the travelogue of a bullet.

This case report involves a 57-year-old male, accidentally shot in the chest with a small bore firearm. The bullet entered the left hemithorax, disrupting the left internal mammarian artery. It then penetrated the anterior wall of the right ventricle causing a pericardial tamponade. After leaving the base of the right heart it perforated the diaphragm, the liver, the spleen and the pancreas. Finally, it penetrated the abdominal aorta 3 cm proximally to the coeliac trunk and reached its final position paravertebrally. This case report illustrates that the management of even minimum gunshot wounds requires a maximum variety of surgical skills.

Ten-year follow-up of endovascular aneurysm treatment with Talent stent-grafts.

The purpose of this study was to evaluate the clinical results, complications, and secondary interventions during long-term follow-up after endovascular aneurysm repair (EVAR) and to investigate the impact of endoleak sizes on aneurysm shrinkage. From 1997 to March 2007, 127 patients (12 female, 115 male; age, 73.0 +/- 7.2 years) with abdominal aortic aneurysms were treated with Talent stent-grafts. Follow-up included clinical visits, contrast-enhanced MDCT, and radiographs at 3, 6, and 12 months and then annually. Results were analyzed with respect to clinical outcome, secondary interventions, endoleak rate and management, and change in aneurysm size. There was no need for primary conversion surgery. Thirty-day mortality was 1.6% (two myocardial infarctions). Procedure-related morbidity was 2.4% (paraplegia, partial infarction of one kidney, and inguinal bleeding requiring surgery). Mean follow-up was 47.7 +/- 34.2 months (range, 0-123 months). Thirty-nine patients died during follow-up; three of the deaths were related to aneurysm (aneurysm rupture due to endoleak, n = 1; secondary surgical reintervention n = 2). During follow-up, a total of 29 secondary procedures were performed in 19 patients, including 14 percutaneous procedures (10 patients) and 15 surgical procedures (12 patients), including 4 cases with late conversion to open aortic repair (stent-graft infection, n = 1; migration, endoleak, or endotension, n = 3). Overall mean survival was 84.5 +/- 4.7 months. Mean survival and freedom from any event was 66.7 +/- 4.5 months. MRI depicted significantly more endoleaks compared to MDCT (23.5% vs. 14.3%; P < 0.01). Patients in whom all aneurysm side branches were occluded prior to stent-grafting showed a significantly reduced incidence of large endoleaks. Endoleaks >10% of the aneurysm area were associated with reduced aneurysm shrinkage compared to no endoleaks or <10% endoleaks (Delta at 3 years, -1.8% vs. -12.0%; P < 0.05). In conclusion, endovascular aneurysm treatment with Talent stent-grafts demonstrated encouraging long-term results with moderate secondary intervention rates. Primary occlusion of all aortic side branches reduced the incidence of large endoleaks. Large endoleaks significantly impaired aneurysm shrinkage, whereas small endoleaks did not.

Gadofosveset-enhanced MR angiography of the pedal arteries in patients with diabetes mellitus and comparison with selective intraarterial DSA.

To compare gadofosveset-enhanced magnetic resonance angiography (MRA) of the pedal vasculature with selective intraarterial DSA. Eighteen patients with PAOD and type II diabetes were prospectively examined at 1.5 T. For contrast enhancement, 0.03 mmol/kg body weight gadofosveset was used. MR imaging consisted of dynamic and of high-resolution steady-state imaging. Selective digital subtraction angiography (DSA) was performed within 5 days and served as standard of reference. Image analysis was done by two observers. There were no differences between MRA and DSA regarding overall image quality. First-pass MRA detected significantly more patent vessel segments than did DSA (P<0.001, kappa=0.46). Interobserver agreement of MRA was very good with respect to the detection of patent vessel segments and the assessment of hemodynamically relevant stenoses (kappa=0.97 and 0.89, respectively). Steady-state imaging depicted significantly more patent metatarsal arteries than did dynamic imaging, and delineated inflammatory complications including osteomyelitis, soft-tissue abscesses, and fistulas related to the diabetic foot. Gadofosveset-enhanced MRA of the pedal vasculature proved to be superior to DSA. It offered a long imaging time window, and allowed for better depiction of the pedal outflow. Steady-state imaging delineated inflammatory complications associated with the diabetic foot.

Questionable value of adjuvant arteriovenous fistula in pedal bypass at high risk for early failure.

Results of an adjuvant arteriovenous fistula (AVF) in pedal bypass surgery in the presence of poor status of the recipient artery, severely impaired intraoperative runoff, or revision for early failure and flow restitution were analyzed in a retrospective study. From January 1998 to December 2006, 24 adjuvant AVFs were constructed in autologous vein or composite pedal bypasses with low intraoperative bypass flow, poor status of the pedal artery, or during successful early bypass revision to prevent graft failure. All infrainguinal bypass operations were registered in a computerized database and prospectively followed. Pedal bypasses with adjunctive AVF were reviewed for fistula function, graft patency, limb salvage, and patient survival. Primary and secondary bypass patency rates at 1 year were 59% and 77%, respectively, with an AVF patency of 36%. Four legs were amputated despite a patent bypass with patent AVF on three occasions. The corresponding limb salvage rate was 65% at 1 year. Patient survival was 50% at 3 years. Adjuvant AVF constructed in grafts considered at high risk for early failure in pedal vein graft or composite bypass does not seem to prevent future graft failure. In patent bypasses the fistula has a significant tendency for spontaneous occlusion. It may be considered in the use of prosthetic composite pedal grafts in selected cases.

Femoropopliteal prosthetic bypass with glutaraldehyde stabilized human umbilical vein (HUV).

OBJECTIVE: Femoropopliteal bypass still is the standard surgical therapy for disabling claudication and critical ischemia. When autologous vein is not suitable synthetic or biological prostheses may be considered. Second generation glutaraldehyde tanned human umbilical vein (HUV) graft was chosen for above and below knee femoropopliteal bypass when autologous vein was not available. A single center experience regarding long-term graft function, secondary reinterventions, and potential biodegeneration of the HUV is presented. METHODS: Between January 1994 and January 2005, 211 consecutive femoropopliteal bypass operations with HUV (65 above knee and 146 below knee) were performed in 197 patients for disabling claudication (57), chronic critical ischemia (130), popliteal artery aneurysm (9), acute ischemia (14), or aneurysmal degeneration of a synthetic graft (1) in the absence of suitable ipsilateral great saphenous vein. Grafts were followed with duplex scan supplemented by additional angiography in case of recurrent ischemia with prospective documentation of follow-up data in a computerized vascular database. Surveillance of the HUV included routine evaluation of potential biodegeneration with duplex scan. Retrospective analysis of graft patency, limb salvage, and signs of aneurysmal degeneration was performed. RESULTS: Mean (median) follow-up was 44 (35) months (range 1 to 143 months). Thirty-day mortality was 2.4%. Early postoperative bypass thrombosis after a median of 4 days postoperatively (0 to 30 days) prompted revision with thrombectomy in 16% of cases. Besides late bypass thrombosis in 14.7%, additional operative or endovascular reinterventions during follow-up to maintain or restore graft patency was necessary in 8.5% of bypasses. Primary, primary assisted, secondary patency rate, and limb salvage rate after 5 years were 54%, 63%, 76%, and 92%, respectively, for all bypasses with no significant difference between above and below knee anastomosis. Duplex scan identified segmental aneurysmal degeneration in six grafts, which led to operative reintervention in three cases. The rate of detected aneurysm for grafts patent for more than three years was 7% with a rate of reintervention for aneurysm of 3.5%. CONCLUSION: Although a considerable rate of early thrombotic occlusions occurred, excellent secondary graft patency and limb salvage combined with a tolerable rate of late aneurysmal degeneration detected by means of duplex scan surveillance justify the use of the HUV in femoropopliteal bypass surgery when ipsilateral autogenous vein is not suitable.

Ischemia-Reperfusion Injury : Pathophysiology and Clinical Implications.

The term ischemia-reperfusion injury describes the experimentally and clinically prevalent finding that tissue ischemia with inadequate oxygen supply followed by successful reperfusion initiates a wide and complex array of inflammatory responses that may both aggravate local injury as well as induce impairment of remote organ function. Conditions under which ischemia-reperfusion injury is encountered include the different forms of acute vascular occlusions (stroke, myocardial infarction, limb ischemia) with the respective reperfusion strategies (thrombolytic therapy, angioplasty, operative revascularization) but also routine surgical procedures (organ transplantation, free-tissue-transfer, cardiopulmonary bypass, vascular surgery) and major trauma/shock. Since the first recognition of ischemia-reperfusion injury during the 1970s, significant knowledge has accumulated and the purpose of this review is to present an overview over the current literature on the molecular and cellular basis of ischemia-reperfusion injury, to outline the clinical manifestations and to compile contemporary treatment and prevention strategies. Although the concept of reperfusion injury is still a matter of debate, it is corroborated by recent and ongoing clinical trials that demonstrated ischemic preconditioning, inhibition of sodium-hydrogen-exchange and administration of adenosine to be effective in attenuating ischemia-reperfusion injury.

MRI versus helical CT for endoleak detection after endovascular aneurysm repair.

OBJECTIVE: The objective of our study was to investigate the diagnostic accuracy of MRI and helical CT for endoleak detection. SUBJECTS AND METHODS: Fifty-two patients underwent endovascular aneurysm repair with nitinol stent-grafts. Follow-up data sets included contrast-enhanced biphasic CT and MRI within 48 hr after the intervention; at 3, 6, and 12 months; and yearly thereafter. The endoleak size was categorized as < or = 3%, > 3% < or = 10%, > 10% < or = 30%, or > 30% of the maximum cross-sectional aneurysm area. A consensus interpretation of CT and MRI was defined as the standard of reference. RESULTS: Of 252 data sets, 141 showed evidence for endoleaks. The incidence of types I, II, and III endoleaks and complex endoleaks was 3.2%, 40.1%, 8.7%, and 4.0%, respectively. The sensitivity for endoleak detection was 92.9%, 44.0%, 34.8%, and 38.3% for MRI, biphasic CT, uniphasic arterial CT, and uniphasic late CT, respectively. The corresponding negative predictive values were 91.7%, 58.4%, 54.7%, and 56.1%, respectively. The overall accuracy of endoleak detection and correct sizing was 95.2%, 58.3%, 55.6%, and 57.1% for MRI, biphasic CT, uniphasic arterial CT, and uniphasic late CT, respectively. CONCLUSION: MRI is significantly superior to biphasic CT for endoleak detection and rating of endoleak size, followed by uniphasic late and uniphasic arterial CT scans. MRI shows a significant number of endoleaks in cases with negative CT findings and may help illuminate the phenomenon of endotension. Endoleak rates reported after endovascular aneurysm repair substantially depend on the imaging techniques used.

Systemic pulsatile pressure in type II endoleaks after stent grafting of experimental abdominal aortic aneurysms.

PURPOSE: To investigate pressure and maximum rate of rise of systolic pressure (peak dP/dt) in completely excluded aneurysms and endoleaks to determine the hemodynamic impact of endoleaks. METHODS: In mongrel dogs (n = 36) experimental aneurysms were created by insertion of a patch (portion of rectus abdominis muscle sheath) into the infrarenal aorta. In group I (n = 18), all aortic branches of the aneurysm were ligated and all aneurysms were completely excluded by stent grafts. Group II (n = 18) consisted of aneurysms with patent aortic side branches that represented sources of endoleaks. One week (n = 12), six weeks (n = 12), and six months (n = 12) after stent grafting, hemodynamic measurements were obtained in thrombosed aneurysms and proved endoleaks. Systemic blood pressure and intraaneurysmal pressure were simultaneously measured and the respective peak dP/dt were computed. RESULTS: At the six-month follow-up, the systolic-pressure ratio (intraaneurysmatic pressure: systemic pressure) was significantly increased in endoleaks compared to non-perfused areas (0.879 +/- 0.042 versus 0.438 +/- 0.176, p < 0.01, group II) or completely excluded aneurysms (0.385 +/- 0.221, group I). Peak dP/dt ratio (intraaneurysmal peak dP/dt: systemic peak dP/dt) was 0.922 +/- 0.154 in endoleaks, compared to 0.084 +/- 0.080 in non-perfused areas (group II, p < 0.01), and was 0.146 +/- 0.121 in completely excluded aneurysms (group I). The diastolic-pressure ratio was also increased in endoleaks compared to non-perfused areas (0.929 +/- 0.088 versus 0.655 +/- 0.231, p < 0.01, group II) or completely excluded aneurysms (0.641 +/- 0.278, group I). In excluded aneurysms, pressure exposure declined as the length of the follow-up period increased. CONCLUSION: Type II endoleaks transmit pulsatile pressure of near systemic level and indicate insufficient treatment result. In contrast, complete endovascular exclusion of aneurysms results in significantly reduced pressure exposure.

Endovascular aneurysm repair: Magnetic resonance monitoring of histological organization processes in the excluded aneurysm.

BACKGROUND: The purpose of the present study was to systematically analyze the histopathologic organization processes in excluded aneurysms after endovascular stenting and to develop a noninvasive monitoring method for these processes using MRI. METHODS AND RESULTS: In 36 mongrel dogs, autologous aortic aneurysms were created. Endovascular treatment was performed using covered stents. Follow-up was after 1 week, 6 weeks, and 6 months. MRI was performed with T2-weighted turbo-spin-echo sequences and T1-weighted spin-echo sequences and was repeated after contrast bolus with gadolinium. Histopathologic findings were correlated to signal intensities (SIs) of MRI images. SIs of distinct areas were analyzed and related to the SI of the reference tissue (SI ratio). The histological organization process was gradated in the following 4 classes: class 0, detritus without organization; classes I and II, connective tissue proliferation with increasing fiber synthesis; and class III, dense fibrous connective tissue. The SI ratios of T2-weighted images were significantly reduced from 4.76 in detritus (0) to 1.70 in dense fibrous connective tissue (III) as a function of histopathologic classes. SI ratios of T1-weighted images were reduced from 1.84 (0) to 1.12 (III). Contrast bolus with gadolinium-DTPA showed no change of SI ratio in detritus (0.99) but an increase from 1.12 (I) to 1.70 (III) as organization increased. CONCLUSIONS: The histological organization of excluded aneurysms can be monitored by MRI. Progressive organization is indicated by decreasing SIs in T2- and an increasing signal increase in T1-weighted images after gadolinium bolus.

[Endovascular aneurysm therapy--long-term treatment outcomes after 7 years]. / Endovaskuläre Aneurysmatherapie--Langzeitergebnisse nach 7 Jahren.

BACKGROUND: Stentgrafts for endovascular treatment of abdominal aortic aneurysms (AAA) have been commercially available since 1994, with now large numbers of implantations all over the world. PATIENTS AND METHODS: From 1994-2001, 115 patients were treated with Stentor, Vanguard and Talent stentgrafts in our institution. RESULTS: Late complications of the first- and second-generation stentgrafts as radiologic or surgical interventions to maintain complete exclusion of the aneurysm amounted to 30% with an additional 22% for observed endoleaks and configuration changes of the stentgraft. Third-generation stentgrafts had a lower complication rate of 12.2% for interventions and 18.3% for late endoleaks and graft changes. CONCLUSION: High costs of the devices, a pretty high late complication rate, and the uncertain maintenance of stentgraft function to prevent aneurysm rupture currently limit the widespread application of this new technology, leaving conventional aneurysmectomy the standard for aneurysm treatment and reserving the endovascular method for selected patients.

[Interdisciplinary diagnosis and therapy of ischemic-osteomyelitic diabetic foot syndrome]. / Interdisziplinäre Diagnostik und Therapie des ischämisch-osteomyelitischen diabetischen Fusssyndroms.

Advanced stages of the diabetic foot syndrome complicated by ischemia and osteomyelitis frequently result in minor amputation, followed by impaired wound healing and higher-level amputation in the context of regular health structures. Even in specialized foot care centers, peripheral arterial occlusive disease and osteomyelitis still represent the greatest challenge in the strife for limb salvage. Whereas the treatment of nonischemic foot lesions has increasingly become a matter of conservative medicine within recent years, for advanced diabetic foot wounds a multidisciplinary treatment policy is essential. A well-coordinated treatment concept aiming at the elimination of the most relevant prognostic factors ischemia and osteomyelitis is required to achieve high limb salvage rates. Surgical revascularization by distal bypass is a crucially important element of this approach. Percutaneous transluminal angioplasty represents a complementary option for short-segment arterial occlusive disease. Foot-sparing minor surgery improves healing time and rates. A specialized diabetologic foot care clinic provides preclinical diagnosis, planning of inpatient procedures, and selection of patients requiring hospitalization for surgical intervention. In addition, it safeguards postinterventional care for wounds with secondary healing and measures of secondary prevention.