Wound Closure After Port Implantation-A Randomized Controlled Trial Comparing Tissue Adhesive and Intracutaneous Suturing.

BACKGROUND: Wound healing after pectoral port implantation is a major factor determining the success or failure of the procedure. Infection and wound dehiscence can endanger the functionality of the port system and impede chemotherapy. The cosmetic result is important for patient satisfaction as well. METHODS: From August 2015 to July 2017, adult patients with an indication for port implantation were entered into a prospective, randomized and controlled single-center study. The skin incision was closed either with tissue adhesive or with an intracutaneous suture. The primary endpoints were the total score of the scar evaluated by the patient and the investigator on the POSAS scale (Patient and Observer Scar Assessment Scale: 6 [normal skin] to 60 points), blinded assessment of photographic documentation by ten evaluating physicians, and the patient's reported quality of life. The calculation of case numbers was based only on the patients' overall POSAS assessment, which was tested for non-inferiority. The secondary endpoints were other complications (infection, dehiscence) and the duration of wound closure (trial registration number NCT02551510). RESULTS: 156 patients (60 ± 13 years, 64% women) participated in the study. The patient-assessed total POSAS score of tissue adhesive revealed non-inferiority to suturing (adhesive 11.7 ± 5.8 vs. suture 10.1 ± 4.0, p for non-inferiority <0.001). Both the investigators in their POSAS assessments and the blinded physician evaluators in their assessment of photographically documented wounds rated wound closure by suturing better than closure with tissue adhesive. No significant differences were found between groups with respect to quality of life or the frequency of wound infection or dehiscence. CONCLUSION: Closure of the upper cutaneous layer with tissue adhesive is a suitable and safe method of wound closure after port implantation.

Robotic hepatic surgery in malignancy: review of the current literature.

The use of minimally invasive liver surgery, such as laparoscopic and robotic surgery, is increasing worldwide. Robot-assisted laparoscopy is a new surgical technique that improves surgical handling. The advantage of this technique is improved dexterity, which leads to increased surgical precision and no tremor or fatigue. Comparable oncological results were documented for laparoscopic and open surgery. Currently, "conventional" laparoscopic liver surgery has limitations with respect to the treatment of lesions in the posterior-superior segments, and there are limited technical features for the reconstruction steps. These limitations might be overcome with the use of robotic surgery. The use of robotic surgery for hepatic procedures originated because of the technical potential to overcome several of the major technical limitations known from conventional laparoscopy and the possibility of performing more extended liver resections. Additionally, there is increasing evidence indicating that robotic hepatic surgery is feasible and safe in resections of the posterior segments. Studies showed that using the robotic technique is associated with a decreased or at least equal amount of intraoperative blood loss compared to that of the conventional laparoscopic or open technique. There is increasing evidence that robotic liver surgery might be as safe as conventional laparoscopic procedures in cancer cases in terms of resection margins, disease-free and overall survival. Furthermore, robotic surgery might be more favorable with respect to postoperative patient recovery. Despite promising results, still large, multicenter, randomized and prospective studies are needed to analyze the exact value of robotic liver surgery in patients with malignant liver tumors.

Acute Stroke Treatment by Surgical Recanalization of Extracranial Internal Carotid Artery Occlusion: A Single Center Experience.

Ischemic stroke due to an acute occlusion of the extracranial internal carotid artery (eICA) is associated with high morbidity and mortality. The best treatment option remains unclear. This study aims to increase the available therapeutic experience documented for surgical recanalization of acute eICA occlusions. We retrospectively reviewed all hospital records of the University Hospital Jena between 2006 and 2018 to identified patients with acute ischemic stroke due to an occlusion of the eICA who underwent emergent surgical recanalization. We analyzed clinical data, surgical reports, imaging data, and outpatient records. The primary outcome parameter was the modified Rankin Scale (mRS) at 3 months. During the survey, 12 patients (mean age: 62.3 ± 10.8 years; range: 35-87) underwent emergent surgical recanalization for an acutely symptomatic eICA occlusion. All patients presented with neurological deficits with a mean National Institutes of Health Stroke Scale score at admission of 15.0 ± 5.1 (range 2-23). Patients were selected for surgery mainly due to the extent of the perfusion mismatch, while stroke severity and age were also considered. The median time from symptom onset to surgery was 309 ± 122 minutes (range 112-650 minutes). Complete recanalization was obtained in all 12 patients. No patient deteriorated postoperatively, no intracranial hemorrhage was observed, and no patient died in the following 3 months. Favorable outcomes (mRS: 0-2) after 3 months were achieved in 7 of 12 patients. The current study adds support to previous findings that the surgical recanalization of acute eICA occlusions is a possible and safe treatment option. However, a critical patient selection based on mismatch size in perfusion imaging is crucially important for successful treatment.

[Endovascular Therapy of Splanchnic Artery Aneurysms: For Each and Every Aneurysm?] / Endovaskuläre Therapie von Viszeralarterienaneurysmata ­ geht das immer?

True visceral artery aneurysms (VAA) and visceral artery pseudoaneurysms (VAPA) are located in the celiac trunk, the superior mesenteric artery and inferior mesenteric artery. In addition to surgical treatment, endovascular embolisation therapy of visceral aneurysms and pseudoaneurysms is an alternative interventional method that has developed precipitously over the last two decades and is considered a first-choice method in many centres. The procedure is characterised by a high technical success rate with a low complication rate. This article presents the basic principles of endovascular treatment and discusses the indications and limitations of the procedure.

Bowel Ischemia in ICU Patients: Diagnostic Value of I-FABP Depends on the Interval to the Triggering Event.

BACKGROUND: Intestinal fatty acid-binding protein (I-FABP) has been shown to be of high diagnostic value in patients with acute mesenteric ischemia. Whether these results can be reproduced in critically ill patients on the ICU was to be investigated. MATERIALS AND METHODS: I-FABP was measured in serum and urine of 43 critically ill patients in ICU when mesenteric ischemia was suspected. Bowel ischemia was confirmed in 21 patients (group 1). 22 patients who survived at least seven days without confirmation of ischemia were assigned to group 2. I-FABP levels were compared between the groups, and interval from the event that has triggered ischemia to I-FABP measurement was recorded. RESULTS: For the identification of patients with mesenteric ischemia, sensitivity, specificity, and area under the curve (AUC) for serum and urine I-FABP were 33.3%, 95.5%, and 0.565 and 81.3%, 70.0%, and 0.694, respectively. I-FABP measurements performed within 12 to 48 h after the event that triggered ischemia showed a sensitivity, specificity, and AUC for serum and urine of 75%, 100%, and 0.853 and 100%, 73.3%, and 0.856, respectively. CONCLUSIONS: In ICU patients, one single I-FABP measurement at the time of clinical suspicion failed to reliably detect or exclude mesenteric ischemia. A higher diagnostic value of I-FABP was only confirmed in the early stages of mesenteric ischemia. I-FABP may be used most appropriately in perioperative monitoring.

Hemodynamic aspects of reduced platelet adhesion on bioinspired microstructured surfaces.

Occlusion by thrombosis due to the absence of the endothelial cell layer is one of the most frequent causes of failure of artificial vascular grafts. Bioinspired surface structures may have a potential to reduce the adhesion of platelets contributing to hemostasis. The aim of this study was to investigate the hemodynamic aspects of platelet adhesion, the main cause of thrombosis, on bioinspired microstructured surfaces mimicking the endothelial cell morphology. We tested the hypothesis that platelet adhesion is statistically significantly reduced on bioinspired microstructured surfaces compared to unstructured surfaces. Platelet adhesion as a function of the microstructure dimensions was investigated under flow conditions on polydimethylsiloxane (PDMS) surfaces by a combined experimental and theoretical approach. Platelet adhesion was statistically significantly reduced (by up to 78%; p≤0.05) on the microstructured PDMS surfaces compared to that on the unstructured control surface. Finite element method (FEM) simulations of blood flow dynamic revealed a micro shear gradient on the microstructure surfaces which plays a pivotal role in reducing platelet adhesion. On the surfaces with the highest differences of the shear stress between the top of the microstructures and the ground areas, platelet adhesion was reduced most. In addition, the microstructures help to reduce the interaction strength between fluid and surfaces, resulting in a larger water contact angle but no higher resistance to flow compared to the unstructured surface. These findings provide new insight into the fundamental mechanisms of reducing platelet adhesion on microstructured bioinspired surfaces and may lay the basis for the development of innovative next generation artificial vascular grafts with reduced risk of thrombosis.

[Management of complications after reconstruction of mesenteric arteries]. / Management von Komplikationen nach Rekonstruktion viszeraler Arterien.

Because of the low ischemia tolerance of abdominal organs and the comorbidities of patients with abdominal ischemic syndromes, complications after the reconstruction of visceral arteries are often severe and associated with a significant mortality rate. The possible complications after interventions on the visceral arteries and their treatment are presented. Endovascular procedures have gained an increasingly important role in many primary interventions as well as in the treatment of complications.

Decreased regulatory T cells in vulnerable atherosclerotic lesions: imbalance between pro- and anti-inflammatory cells in atherosclerosis.

Atherosclerosis is a chronic inflammatory disease of the arterial wall in which presentation of autoantigens by dendritic cells (DCs) leads to the activation of T cells. Anti-inflammatory cells like Tregs counterbalance inflammation in atherogenesis. In our study, human carotid plaque specimens were classified as stable (14) and unstable (15) according to established morphological criteria. Vessel specimens (n = 12) without any signs of atherosclerosis were used as controls. Immunohistochemical staining was performed to detect different types of DCs (S100, fascin, CD83, CD209, CD304, and CD123), proinflammatory T cells (CD3, CD4, CD8, and CD161), and anti-inflammatory Tregs (FoxP3). The following results were observed: in unstable lesions, significantly higher numbers of proinflammatory cells like DCs, T helper cells, cytotoxic T cells, and natural killer cells were detected compared to stable plaques. Additionally, there was a significantly higher expression of HLA-DR and more T cell activation (CD25, CD69) in unstable lesions. On the contrary, unstable lesions contained significantly lower numbers of Tregs. Furthermore, a significant inverse correlation between myeloid DCs and Tregs was shown. These data suggest an increased inflammatory state in vulnerable plaques resulting from an imbalance of the frequency of local pro- and anti-inflammatory immune cells.

Quantitative characterization of endothelial cell morphologies depending on shear stress in different blood vessels of domestic pigs using a focused ion beam and high resolution scanning electron microscopy (FIB-SEM).

Microstructured surfaces mimicking the endothelial cell (EC) morphology is a new approach to improve the blood compatibility of synthetic vascular grafts. The ECs are capable of changing their shapes depending on different shear conditions. However, the quantitative correlation between EC morphology and shear stress has not yet been investigated statistically. The aim of this study was to quantitatively investigate the morphology of ECs in dependence on the shear stress. Blood flow rates in different types of natural blood vessels (carotid, renal, hepatic and iliac arteries) originated from domestic pigs were first measured in vivo to calculate the shear stresses. The EC morphologies were quantitatively characterized ex vivo by imaging with high resolution scanning electron microscopy (SEM) and cross-sectioning of the cells using a state-of-the-art focused ion beam (FIB). The relationships between EC geometrical parameters and shear stress were statistically analyzed and found to be exponential. ECs under high shear stress conditions had a longer length and narrower width, i.e. a higher aspect ratio, while the cell height was smaller compared to low shear conditions. Based on these results, suitable and valid geometrical parameters of microstructures mimicking EC can be derived for various shear conditions in synthetic vascular grafts to optimize blood compatibility.

Multimodal imaging of aortoiliac occlusive disease with three-dimensional postprocessing of PET angiography and CT.

Two patients with aortoiliac occlusive disease underwent dynamic and late-static positron emission tomography/computed tomography (PET/CT) acquisitions with 257 and 244 MBq F-18 FDG (CT scan parameters 50 mAs, 120 kV, pitch 1.25). Three-dimensional reconstructions revealed an occluded aortic stent and a high-grade aortic stenosis and demonstrated the relations of vascular pathologies to adjacent structures. Early-dynamic PET can be performed without additional radioactive tracer and may be valuable for evaluation and intervention planning in patients with contraindications to other angiographic modalities.

In vivo assessment of the hepatic microcirculation after mesenterico-portal bypass (REX-shunt) using orthogonal polarization spectral imaging.

BACKGROUND: Extrahepatic portal vein thrombosis, not associated with cirrhosis or tumours, is the second most frequent cause of portal hypertension worldwide. Especially in children, anatomic mesenterico-portal interposition (REX-shunt) has become an established treatment. The changes in hepatic microcirculation after reperfusion of the shunt have not been investigated so far. AIMS: This study investigates the hepatic microcirculation before and after REX-shunt interposition using orthogonal polarization spectral imaging (OPS). PATIENTS AND METHODS: Since 2004, three consecutive patients with extrahepatic portal vein thrombosis underwent REX-shunt interposition. We measured the hepatic microcirculation by OPS before and directly after REX-shunt reperfusion and analysed the capillary vessel diameter, red blood cell velocity, functional capillary density and volumetric blood flow. Furthermore, we compared our values with the physiological values of the hepatic microcirculation defined previously by other investigators. RESULTS: All shunts showed an excellent function in the follow-up investigations. The intra-individual microcirculatory analysis revealed a reduction in the red blood cell velocity after shunt reperfusion in particular. CONCLUSIONS: Our results provide preliminary evidence for the reversal of the hepatic arterial buffer response following the restoration of the portal venous blood flow. This may be a short-term effect because of the restored portal venous blood flow.

In vitro testing of a newly developed arteriovenous double-outflow graft.

INTRODUCTION: The long-term prognosis of arteriovenous polytetrafluoroethylene (PTFE) hemodialysis grafts remains poor, causing significant morbidity and costs. The high failure rate is due to a stenosis development of the graft-vein anastomosis, consisting of two pathophysiologically separate and characteristic lesions emerging from two main mechanisms: development of intimal hyperplasia in the vein and pseudointima in the graft. We developed a new venous anastomotic graft design that combines a flow diffuser and flow division, thereby creating a double-channel graft (Bi-Flow graft) and tested it in vitro. METHODS: In vitro experiments have been performed using silastic models of six different anastomotic configurations (straight end-to-side, cuffed Venaflo-type, large and small diffuser, and large and small Bi-Flow) inserted into a pulsatile-flow circuit. The silastic models were created using a computerized numerical control design approach, varying only the venous anastomoses. Velocity fields and shear stresses were obtained using particle image velocimetry, and volumetric flow rates through the models were measured using an ultrasound flowmeter. RESULTS: The hooded graft configurations showed significantly lower shear forces than did the end-to-side anastomosis. The shear stresses in the straight end-to-side graft were as high as arterial wall stresses. Large separation areas were present in the hooded grafts, except for the small Bi-Flow graft, which showed only isolated separation zones near the baffle used to divide the flow. The double-channel grafts exhibited a parabolic flow profile consisting of laminar flow in the double-outflow portion of the model's laminar flow pattern through the venous anastomosis. A marked flow separation was present in the large Bi-Flow model. Volumetric flow measurements revealed an average flow increase of 21% through the small Bi-Flow graft, which was attributed to the optimization of flow dynamics and pattern within the venous anastomosis of the double-channel graft. CONCLUSION: The new arteriovenous Bi-Flow graft design addresses two major problems responsible for the development of venous stenosis of prosthetic hemodialysis grafts in vitro. The new graft design should be further investigated in animal studies.

Proximalization of the arterial inflow: a new technique to treat access-related ischemia.

OBJECTIVE: Arteriovenous access-related ischemia is an uncommon but serious and occasionally devastating complication. Distal revascularization-interval ligation (DRIL) has been established as a standard treatment procedure; however, an axial artery is ligated and the distal perfusion is maintained by the construction of an arterial bypass. Because such an approach, in principle, appears undesirable, we developed and applied an alternative technique referred to as proximalization of the arterial inflow (PAI). This procedure converts the arterial supply of the arteriovenous access to a more proximal artery with higher capacity by using a small-caliber polytetrafluoroethylene graft as a feeder. METHODS: From January 1999 to June 2005, the PAI technique was applied in 30 patients. The indication was seen in patients with severe distal ischemia who had a flow volume rate of <800 mL/min in a native fistula and <1000 mL/min in prosthetic access. RESULTS: Pain was the dominant symptom of ischemia in most patients before surgery. In 37%, a tissue loss was observed. The symptoms of access-related ischemia disappeared completely in 84% of patients and improved significantly in 16%. The significant hemodynamic improvement was confirmed by an increase of the intraoperatively measured mean distal arterial pressure from 32 +/- 9 mm Hg to 63 +/- 8 mm Hg. The digital-brachial index increased from 0.40 +/- 0.10 to 0.83 +/- 0.07. The mean access flow rate was 658 +/- 80 mL/min after PAI and did not differ significantly with the preoperative value (634 +/- 181 mL/min). With a mean follow-up interval of 26.1 +/-19.1 months, the primary and secondary patency rates were, respectively, 87% and 90% at 1 year and 67% and 78% at 3 years. CONCLUSIONS: The PAI procedure represents a well-suited alternative to the DRIL technique for the treatment of patients who develop ischemia after creation of an arteriovenous access. Results for access salvage and disappearance of ischemic symptoms are equivalent to the DRIL technique. In contrast to the DRIL procedure, the PAI technique preserves the natural arterial pathway. Hence, PAI is preferable for surgeons who are reluctant to ligate an axial artery and are concerned about potentially disastrous consequences.