Continuous irrigation as a therapeutic option for graft infections of the groin.

BACKGROUND: Wound infections following vascular procedures occur in 1-7 % of patients and can lead to severe problems including amputation and death. There are no established treatment options for this complication. The aim of our study was to introduce continuous irrigation as a new treatment technique. METHODS: We retrospectively evaluated patients who had undergone bypass surgery involving the groin and had been treated with continuous irrigation because of deep wound infections. The irrigation solution was saline in all cases. The patients were additionally treated with antibiotics. The end point of the study was either complete wound healing or complications such as recurrent infection, amputation, or death. RESULTS: Wound complications occurred in 65 (15.3 %) of 424 operations. Overall, 20 patients (4.7 %) developed a deep wound infection involving prosthetic graft material. They were treated with continuous irrigation. Complete wound healing was achieved in 13 cases (65.0 %). One patient died. No amputations were necessary. CONCLUSIONS: Based on our results, constant irrigation may be a therapeutic option in patients with deep wound infections. The main advantages of continuous irrigation over other treatments are ongoing bacterial reduction despite primary wound closure and the ability to measure the remaining colonization by microbiologic examination of the irrigation fluid.

Proximalization of the arterial inflow: new treatment of choice in patients with advanced dialysis shunt-associated steal syndrome?

Dialysis-associated steal syndrome (DASS) is a potentially devastating complication. As a new surgical technique, proximalization of the arterial inflow (PAI) has been described recently to be of good effect in case of DASS. As there has not yet been much general familiarity with this technique, our aim with this prospective study was to establish its indication for a special group of patients who developed advanced DASS (finger necrosis) following autogenous hemodialysis access (HA). Twenty-three patients (18 brachial, five wrist HA) with advanced DASS underwent PAI. Graft material included either heparinized (13 patients) or nonheparinized (10 patients) polytetrafluoroethylene prosthetic material. Vascular function was evaluated pre- and postoperatively with duplex ultrasound. Procedural success was determined by restitution of limb circulation and preservation of the HA. In 15 cases (65%) symptoms of DASS disappeared completely, and in six patients (26%) adequate wound healing with improvement of symptoms was achieved. Symptoms were persistent in two patients (9%) who had tissue loss >1 cm at the fingertips. Overall there was a significant increase in radial artery flow velocity (from 35.65 +/- 7.69 to 55.21 +/- 8.51 cm/sec, p < 0.005) after PAI. A decrease of fistula flow (from 1.38 +/- 0.48 to 0.94 +/- 0.14 L/min, p = 0.003) was measured in patients with elbow HA but not in patients with wrist HA. Secondary patency after 18 months was 85%. PAI effected an improvement in distal radial artery circulation with an additional banding component in elbow HA. We found that PAI led to good clinical success, especially in patients developing small finger necrosis as a form of advanced DASS. However, in case of severe tissue loss (>1 cm in diameter), PAI was not successful (n = 2). In such situations, other treatment options have to be discussed.

Dialysis shunt-associated steal syndrome (DASS) following brachial accesses: the value of fistula banding under blood flow control.

BACKGROUND: Dialysis shunt-associated steal syndrome (DASS) is a rare complication of hemodialysis access (HA) which preferably occurs in brachial fistulas. Treatment options are discussed controversially. Aim of this study was to evaluate flow-controlled fistula banding. MATERIALS AND METHODS: Patients treated between 2002 and 2006 were included in this prospective survey. According to a classification we established, patients were typed DASS I-III (I: short history, no dermal lesions; II: long history, skin lesions; III: long history, gangrene). Surgical therapy was HA banding including controlled reduction (about 50% of initial flow) of HA blood flow (patients type I and II). Patients with type III underwent closure of the HA. RESULTS: In 15 patients with relevant DASS, blood-flow-controlled banding was performed. In ten patients (all type I), banding led to restitution of the hand function while preserving the HA. In five patients (all type II), banding was not successful; in two patients, closure of the HA was performed eventually. In five patients (type III), primary closure of the HA was performed. Four patients with DASS type II but only two with DASS type I had diabetes mellitus (p = 0.006). CONCLUSIONS: Banding under blood flow control resulting in an approximately 50% reduction in the initial blood flow is an adequate therapeutic option in patients with brachial HA and type I-DASS. In type II-DASS, banding does not lead to satisfying results, more complex surgical options might be more successful. Diabetes is associated with poor HA outcome in case of DASS.

The isoenzyme of glutaminyl cyclase is an important regulator of monocyte infiltration under inflammatory conditions.

Acute and chronic inflammatory disorders are characterized by detrimental cytokine and chemokine expression. Frequently, the chemotactic activity of cytokines depends on a modified N-terminus of the polypeptide. Among those, the N-terminus of monocyte chemoattractant protein 1 (CCL2 and MCP-1) is modified to a pyroglutamate (pE-) residue protecting against degradation in vivo. Here, we show that the N-terminal pE-formation depends on glutaminyl cyclase activity. The pE-residue increases stability against N-terminal degradation by aminopeptidases and improves receptor activation and signal transduction in vitro. Genetic ablation of the glutaminyl cyclase iso-enzymes QC (QPCT) or isoQC (QPCTL) revealed a major role of isoQC for pE(1) -CCL2 formation and monocyte infiltration. Consistently, administration of QC-inhibitors in inflammatory models, such as thioglycollate-induced peritonitis reduced monocyte infiltration. The pharmacologic efficacy of QC/isoQC-inhibition was assessed in accelerated atherosclerosis in ApoE3*Leiden mice, showing attenuated atherosclerotic pathology following chronic oral treatment. Current strategies targeting CCL2 are mainly based on antibodies or spiegelmers. The application of small, orally available inhibitors of glutaminyl cyclases represents an alternative therapeutic strategy to treat CCL2-driven disorders such as atherosclerosis/restenosis and fibrosis.

Proximalization of the arterial inflow (PAI) in patients with dialysis access-induced ischemic syndrome: first report on long-term clinical results.

PURPOSE: Proximalization of the arterial inflow (PAI) is a promising technique which was introduced several years ago as a treatment option for patients with dialysis access-induced ischemic syndrome (DAIIS). In our institutions we have been performing PAI since 2003 and have seen positive clinical results. The aim of this prospective survey is to present the long-term results of PAI. METHODS: Between 2003 and 2008, forty PAI operations were performed in our institutions: 4 patients had acute pain and sensorimotor dysfunction with no lesions, 33 had small acral lesions, and 3 had extended lesions following the creation of autogenous fistulas. In 22 cases a heparinized graft was used and in 18 cases a regular PTFE-graft. Criteria for successful treeatment of the disease course were evaluated by clinical and ultrasound examinations. RESULTS: In 36 cases (90%), PAI led to clinical success which was permanent in 33 patients (82%) seen in the follow-up period of 9 to 40 months. Primary patency was 62% after 12 months and secondary patency was 75% after 18 months. Heparinized grafts led to better patency rates. In 3 out of the 4 patients with large acral lesions, graft explantation was necessary due to infection or failing success. CONCLUSIONS: Based on our experience, clinical long-term results are successful in certain patients with DAIIS. The aim for the near future should be a better patency rate to minimize the need for reoperations. In cases of extended limb necrosis/gangrene results were poor. In such patients primary closure of the access must be discussed.

Dialysis shunt-associated steal syndrome with autogenous hemodialysis accesses: proposal for a new classification based on clinical results.

BACKGROUND: Dialysis-associated steal syndrome (DASS) is a multifactorial complication. There are several therapeutic options, although because of the lack of research decisions for certain procedures are often made individually. The aim of this retrospective survey was to propose a new classification for DASS, including therapeutic recommendations, to make standardized procedures easier. METHODS: A total of 63 patients (2001-2006) treated for DASS following autogenuous hemodialysis access (HA) were included in this survey. In 55 (87%) of these patients, surgery was performed. The courses of disease of the patients were evaluated according to clinical symptoms, HA-specific features, and therapeutic results. Statistical evaluation was performed by SSPS software. RESULTS: Eight patients with mild symptoms were treated successfully using conservative therapy. In 17 patients with pain during exercise or acute neurologic deficiencies, HA banding led to good results. In the case of acral lesions, however, banding was unsuccessful, although interruption of the retrograde flow was sufficient therapy in 94% of cases. Preservation of the HA was unsuccessful in all patients with extended tissue loss (n = 10). Statistical evaluation showed that tissue loss was generally associated with diabetes (p < 0.001) and peripheral arterial occlusive disease (p = 0.001). CONCLUSION: In addition to steal phenomenon (stage I), which can be treated conservatively, there are three stages of DASS following autogenuous HA that require surgical intervention (stage II, no acral lesions; stage III, small acral lesions; stage IV, extended acral lesions). HA banding leads to good results in stage II; in patients with stage III, interruption of the retrograde flow is indicated. However, in patients with extensive tissue loss (stage IV), closure of the HA should be considered.