Tumor necrosis factor-alpha and interleukin-6 release from white blood cells induced by different graft materials in vitro are affected by pentoxifylline and iloprost

Transcatheter Closure of Perimembranous Ventricular Septal Defect Using KONAR-MF™: A Multicenter Experience

Transcatheter closure of perimembranous ventricular septal defect (PmVSD) is an established procedure. However, the occurrence of complete heart block limits its scope. The newer KONAR-MF™ occluder has specific design characteristics that may improve the safety of PmVSD closure. The objective of the study was to describe the efficacy and mid-term follow-up of transcatheter closure of PmVSD using KONAR-MF™. The study was conducted prospectively in 3 Indian centers (January 2018-December 2022). PmVSD closure was done by both antegrade and retrograde methods, and patients were followed up at 1, 3, 6, 12 months, and annually after that. 121 out of 123 patients were included with the following characteristics: median age 4.4 (0.18-40) years; weight 15 (2.1-88) kg; mean Qp/Qs ratio 1.87 ± 0.52 and pulmonary artery mean pressure: 22 ± 6.9 mmHg. The procedure was successful in all but 3; the device was removed due to significant residual shunt (n = 2) and new development of aortic regurgitation (AR) (≥ mild) in 1. The median defect size was 5.2 (2.5-12) mm. Device sizes from 6/4 to 14/12 were deployed (median fluoroscopy time 13.3 min; range 3.6-47.8). Shunt occlusion rates were 90%-Immediate, 95%-pre-discharge, and 97%-1 month, with no instances of complete heart block after the procedure and during follow-up. Six had new onset AR (mild: 2, trivial 4), and one had increased tricuspid regurgitation. All patients were well during follow-up (median: 20 months; range: 6-46). The new KONAR-MF™ occluder appears to be a promising and safe alternative for the closure of the PmVSD; further long-term follow is merited.

Two decades of experience in explantation and graft preserving strategies following primary endovascular aneurysm repair and lessons learned

Objectives

We aim to scrutinize our evolving re-intervention strategies following primary endovascular aortic aneurysm repair (EVAR) - EVAR GORE SalvAge Fabric Technique (ARAFAT), aortic sac double breasting with endograft preservation, and stent-graft explantation.

Methods

We performed 1,555 aortic interventions over the study period, including 910 EVARs. Factors associated with the need for reintervention and the likelihood of chronic fabric fatigue failure (CFFF) were investigated. Using conventional and innovative diagnostic modalities with Prone contrASt enHanced computed tomography Angiography (PASHA), 136 endoleaks (ELs) were identified (15 type I, 98 type II; 18 type III; 5 type IV).

Results

Forty-four (4.84%) patients underwent re-intervention post-primary EVAR; 18 ARAFATs, 12 double breastings, and 14 explantations. Choice of re-intervention was based on patient fitness and mode of failure. Mean EL detection duration following primary EVAR was 53.3 ± 6.82 months, while mean time to re-intervention was 70.20 ± 6.98 months. The mean sac size before the primary EVAR and re-intervention was 6.00 ± 1.75 cm and 7.51 ± 1.94 cm, respectively. Polyester (61.40%) was the most commonly employed stent-graft material. Use of more than three modular stent-graft components (3.42 ± 1.31, p = 0.846); with the proximal stent-graft diameter of 31.6 ± 3.80 cm (p = 0.651) and the use of iliac limbs more than 17 mm (p = 0.364), all added together are contributing factors. We had one peri-operative mortality following explantation due to sepsis-induced multiorgan failure.

Conclusions

Our re-intervention strategies matured from stent graft explantation to graft preservation with endovascular relining of the stent-graft. Graft preservation with aortic sacotomy and double breasting were used to manage concealed ELs due to aortic hygroma.

Incidence and risk factors of post implantation syndrome after elective endovascular aortic aneurysm repair

BACKGROUND

Post implantation syndrome (PIS) represents an acute phase systemic inflammatory response following endovascular aortic aneurysm repair (EVAR). Our objective was to investigate the risk factors associated with the manifestation and severity of PIS with various available stent-grafts.

MATERIALS AND METHODS

We performed a retrospective analysis of prospectively collected data covering the period 2016 - 2020. 191 patients were included. Body temperature was recorded regularly and blood sample was obtained daily. The imaging protocol included computed tomography aortoiliac angiography before surgery and one month after. The volumes of pre-existing and new-onset mural thrombus were calculated in a semiautomated fashion. Five abdominal aortic stent-graft devices were used: Endurant™ ΙΙ, Anaconda™, Treo®, E-tegra® and AFX® 2. Subgroup analysis was performed between woven polyester and ePTFE lined devices.

RESULTS

The incidence of PIS was 21.5%. No significant differences were observed regarding demographics, risk factors, aneurysm anatomy or operative data. The amount of preexisting and new-onset mural thrombus were not related with PIS (p=0.117 and p=0.096). PIS incidence in the polyester subgroup was 24.2%, significantly higher compared to 8.3% in the ePTFE subgroup. In-subgroup analysis revealed that the use of Anaconda™ was associated with the higher frequency (61.1%, p=0.021). Multivariate logistic regression showed that polyester was the single factor significantly associated with PIS (hazard ratio=2.6, p=0.043), as opposed to the new onset thrombus (hazard ratio=1.29, p=0.101).

CONCLUSIONS

PIS is not uncommon and should be taken into consideration in patients presenting with fever after EVAR. The endograft's liner material seems to play the primordial role, with woven polyester to be attributed with significantly higher incidence.

Postimplantation syndrome in endovascular aortic aneurysm repair - a systematic review

Postimplantation syndrome (PIS) following endovascular aortic aneurysm repair (EVAR) is a poorly understood phenomenon occurring in the early post-operative course. The underlying aetiology, risk factors, clinical sequalae, and treatment options, are largely unknown. The lack of any standardised diagnostic criteria limits current research in this field. The MEDLINE database was interrogated using a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) search strategy. Five search terms were used; "postimplantation syndrome" AND "aneurysm", AND "infection", AND "complications", AND "biomarkers", AND "outcomes". 19 studies were included in the review process, reporting a 17.4%-39.0% incidence of PIS. IL-6 was the most commonly elevated biomarker in PIS vs. non-PIS patients. There was a higher incidence of PIS in patients who received polyester rather than expanded-polytetrafluoroethylene (ePTFE) grafts. There was a lower rate of type 2 endoleaks observed in patients who developed PIS. Early major adverse cardiovascular events (MACE) were higher in PIS patients, however there were no studies reporting long-term MACE. Length of stay was higher in PIS patients. Current data support the role of IL-6 as being key to the development of PIS following EVAR. Further work describing the effect that PIS has on long-term clinical outcomes is needed. Lack of standardised diagnostic criteria limit the reporting of PIS between centres, the criteria proposed by this review may resolve this.

Postimplantation Syndrome Is Not Associated with Myocardial Injury after Noncardiac Surgery after Endovascular Aneurysm Repair

BACKGROUND

Postimplantation syndrome (PIS) is the clinical and biochemical expression of an inflammatory response following endovascular aneurysm repair (EVAR), with a reported incidence ranging from 2% to 100%. Although generally benign, some studies report an association between PIS and postoperative major adverse cardiovascular events (MACEs). Nonetheless, the role of PIS in postoperative myocardial injury after noncardiac surgery (MINS) is unknown. This work aims to evaluate the relationship between PIS and MINS in a subset of EVAR patients, as well as assess the impact of PIS in all-cause mortality.

METHODS

All patients undergoing elective standard EVAR between January 2008 and June 2017, and with at least one measurement of contemporary (cTnI) or high sensitivity troponin I (hSTnI) in the first 48h after surgery, were retrospectively analyzed. PIS was defined as the presence of fever and leukocytosis in the postoperative period in the absence of infectious complications. MINS was defined as the value exceeding the 99th percentile of a normal reference population with a coefficient of variation <10%, which was >0.032 ng/mL for cTnI and 0.0114 (female) and 0.027 ng/mL (male) for hSTnI. Patients' demographics, comorbidities, medication, access, and anesthesia were also evaluated.

RESULTS

One hundred thirty-three consecutive patients were included (95.5% male; mean age 75.66 ± 7.13 years). Mean follow-up was 46.35 months. Survival rate was 86.5%, 80.5%, and 57.6% at 1, 3, and 5 years of follow-up, with 2 fatalities at 30 days of follow-up. The prevalence of PIS was 11.4%. MACE occurred in 2.3% of the patients, while MINS was reported in 16.5% of the patients. No association was found between PIS and patients' gender, comorbidities, type of anesthesia, or transfusional support. The type of graft used significantly affected the prevalence of PIS, with all cases reported when polyester grafts were used (P = 0.031). MACE occurred in 2.3% of the patients, while MINS was reported in 16.5% of the patients. PIS was found to be significantly associated with postoperative MACE (P = 0.001), but not MINS. Survival analysis revealed no differences between patients with or without PIS regarding 30-day mortality as well as long-term all-cause mortality. American Society of Anesthesiologists score (hazard ratio [HR] 2.157, 95% confidence interval [CI] 1.07-4.33, P = 0.031) and heart failure (HR 2.284, 95% CI 1.25-4.18, P = 0.008) were found to be independently associated with increased long-term all-cause mortality in this cohort of patients.

CONCLUSIONS

PIS is a common complication after EVAR, occurring in 11.4% of the patients from this cohort. Graft type seems to significantly affect the risk of PIS, since all reported cases occurred when polyester grafts were used. PIS did not influence 30-day or long-term survival and was found to be significantly associated with postoperative MACE but not MINS, suggesting the involvement of different pathophysiological mechanisms.

Polyester Grafts Are a Risk Factor for Postimplantation Syndrome after Abdominal Endovascular Aneurysm Repair: Retrospective Analysis for Polyester Graft, Excluder®, and Endologix Powerlink®/AFX®

Objective: Postimplantation syndrome (PIS) is a postoperative syndrome that occurs after endovascular aneurysm repair (EVAR), accompanied by high fever, leukocytosis, and high serum C-reactive protein (CRP). Its pathogenesis and clinical meaning are still under discussion. Here, we evaluate the relationship between postoperative fever after EVAR and graft fabric focusing on Endologix Powerlink® and AFX® (EPL/AFX).

Materials and Methods: From January 2015 to July 2017, data on elective EVAR for abdominal aortic aneurysm (AAA) using mainbody were retrospectively collected. The primary endpoint was maximal postoperative fever.

Results: We identified 128 patients who underwent elective EVAR for AAA (105 males, 82%; aged 57–90, median: 74 years). The median maximal postoperative fever was 37.8°C (36.6–39.7°C): polyester graft, 38.2°C (37.1–39.7°C); Excluder®, 37.8°C (36.6–39.2°C); and EPL/AFX, 37.7°C (37–38.7°C). The maximal postoperative fever with a polyester graft was significantly higher than that with an expanded polytetrafluoroethylene (ePTFE) graft (p<0.001). However, there was no difference between Excluder® and EPL/AFX (p=0.214).

Conclusion: In this study, it was found that polyester grafts are significantly associated with PIS after elective EVAR for AAA. If patient anatomy is permitted, it may be better to choose the ePTFE graft, especially for patients with a poor general condition.

De novo periaortic fibrosis after endovascular aortic repair

We report a case of a 63-year-old man presenting with abdominal pain and hydronephrosis secondary to periaortic fibrosis (PAF) 8 months after an endovascular aortic repair (EVAR) using a woven polyester bifurcated graft. De novo delayed PAF after open repair is rare and even more infrequent after EVAR. All 3 previously reported cases occurred after woven polyester grafts and no reported cases after polytetrafluorethylene grafts. Management included steroidal anti-inflammatory treatment and bilateral double J tube placement. Satisfactory results were obtained.

Pentoxifylline influences the autocrine function of organ cultured donor corneas and enhances endothelial cell survival

BACKGROUND/AIMS

Scientific interest in pentoxifylline has been reawakened owing to the recognised effects of this drug on immune functions, particularly its influence on cytokine production. In a previous study, the authors demonstrated that spiking of organ culture media with endotoxin elicited a marked enhancement in the release of IL-6 and IL-8 from corneal tissue and that these events coincided with degenerative changes in endothelial cells and a higher incidence of actual loss among this population. Since traces of donor derived endotoxin can be detected in up to 50% of corneal organ cultures, this substance may have a direct influence on graft viability or trigger inflammatory responses in the host. They, therefore, wished to ascertain whether supplementation of media with pentoxifylline improved endothelial cell survival in organ cultured donor corneas.

METHODS

12 fellow pairs of donor corneas were cultured for 20 days, with a change of medium on day 10: One of each pair was incubated in the absence, and the other in the presence, of pentoxifylline (25 microg/ml). Samples of medium were withdrawn at regular intervals during the course of incubation and screened for cytokines IL-6, IL-8, and prostaglandin E2 by ELISA. Endothelial cell morphology and numerical density were assessed on days 0, 10 and 20.

RESULTS

Addition of pentoxifylline to organ culture media led to a significant improvement in endothelial cell survival. This drug also elicited a significant increase in the level of IL-6 and marginally suppressed that of IL-8 during the initial 10 day phase of incubation. During the second 10-20 day phase, the level of both IL-6 and IL-8 decreased significantly in the presence of pentoxifylline, the relation between these two cytokines being the inverse of that observed in the absence of the drug. No significant changes in the level of prostaglandin E2 were apparent.

CONCLUSION

The addition of pentoxifylline to organ culture media leads, ultimately, to a suppression of IL-6 and IL-8 secretion by corneal tissue. The potentially damaging effects of these cytokines are thereby quelled, as evidenced by the improvement in endothelial cell survival.

Biocompatible hydrogel supports the growth of respiratory epithelial cells: possibilities in tracheal tissue engineering

Extensive tracheal defect reconstruction is a major challenge in plastic and reconstructive surgery. The lack of an epithelial lining on the luminal surfaces of tracheal prostheses is among the major causes of their failure. Chitosan-gelatin hydrogels were synthesized for the development of biocompatible, growth-supportive substrata for respiratory epithelial cells. We employed J774 macrophages to test the immunocompatibility of this gel. The hydrogel did not exert a cytotoxic effect on macrophages, as confirmed by tetrazolium reduction and neutral red uptake assay. Flow cytometric analysis of macrophages cultured on the hydrogel showed a comparable expression of activation markers CD11b/CD18, CD45, and CD14 to the control. Semiquantitative RT-PCR results showed an absence of upregulation of interleukin-6 (IL-6) and TNF-alpha in these macrophages with respect to the controls. Primary human respiratory epithelial cells cultured on the hydrogel showed proper attachment, normal morphology, and growth. A small proportion of cells on the hydrogel showed synchronously beating cilia. RT-PCR analysis showed that cells on the hydrogel expressed mucins 2 and 5 and cytokeratin 13, which are markers for secretory goblet and squamous cells, respectively. All these results demonstrate that the hydrogel supports the growth of a mixed population of differentiated epithelial cells. This hydrogel is suitable as a culture substratum for respiratory epithelial cells and could be used as a potential candidate for coating tracheal prostheses.

Interleukin-1 receptor type I gene-deficient mice are less susceptible to Staphylococcus epidermidis biomaterial-associated infection than are wild-type mice

Elevated concentrations of interleukin-1 (IL-1) were found in tissue surrounding biomaterials infected with Staphylococcus epidermidis. To determine the role of IL-1 in biomaterial-associated infection (BAI), IL-1 receptor type I-deficient (IL-1R(-/-)) and wild-type mice received subcutaneous implants of silicon elastomer (SE) or polyvinylpyrrolidone-grafted SE (SEpvp), combined with an injection of 10(6) CFU of S. epidermidis or sterile saline. Neither mouse strain was susceptible to BAI around SE. IL-1R(-/-) mice with SEpvp implants had a no abscess formation and a reduced susceptibility to persistent S. epidermidis infection. The normal foreign body response, characterized by giant-cell formation and encapsulation, was delayed around SEpvp in wild-type mice but not in IL-1R(-/-) mice. This coincided with enhanced local IL-4 production in IL-1R(-/-) mice. These data suggest that inhibition of local IL-1 activity may be beneficial for the outcome of BAI.

Pentoxifylline improves learning and memory in glutamate-lesioned rats

The present work shows the effects of pentoxifylline (ptx), on learning and memory in rats with hippocampal lesions induced by glutamate (glu). Immediately after stereotaxic procedures and in the absence or presence of glu lesions, animals were treated with ptx (50, 100, or 200 mg/kg, IP) for 6 days. Twenty-four hours after the last injection, behavior and memory tests were performed, animals were sacrificed, and hippocampi dissected for cAMP determination or histopathological studies. Results from the T-maze task showed a less learning ability in the glu-lesioned group compared to other ones. Ptx alone or associated with glu significantly improved memory acquisition, but not memory consolidation compared to glu-lesioned rats. Except for the increased locomotor activity observed in the ptx100+glu-treated group compared to saline, no other difference was detected in the open-field test. A significant impairment in avoidance performance was observed in glu-lesioned group as compared to saline or to other groups in the short as well as in the late phase of memory. All groups showed an improved water-maze performance over time with similar performances on the final day of acquisition. The impairment in memory retention observed in glu-lesioned rats was reversed by the pretreatment with ptx200. Glu induced hippocampal lesion and reduced cAMP levels. Both effects were blocked by ptx, suggesting that its action may be the result of increased cAMP levels and/or inhibition of adenosine A1 receptors.

Subcutaneous abscess formation around catheters induced by viable and nonviable Staphylococcus epidermidis as well as by small amounts of bacterial cell wall components

The use of catheters is often complicated by infection, mainly due to Staphylococcus epidermidis. Recently, a novel poly(vinylpyrrolidone)-grafted silicone elastomer catheter (SEpvp) was introduced. Less bacteria adhered to SEpvp than to conventional SE catheters in vitro. The frequency of S. epidermidis infection associated with SEpvp and SE was assessed in a rabbit model. Unexpectedly, abscesses were induced by the injection of low numbers of S. epidermidis along subcutaneously inserted SEpvp. No abscesses were seen around SE, even when very high numbers of S. epidermidis were injected. This bioincompatibility reaction observed around the SEpvp was independent of the host, bacterial strain, and method of inoculation. Abscesses were also induced by nonviable S. epidermidis and by bacterial cell wall components. Because these incompatibility reactions were not observed in the absence of bacteria, biocompatibility testing should include experiments in which the inflammatory effects of the combination of catheter and (non)viable bacteria are tested.

The inflammatory response following treatment of abdominal aortic aneurysms: a comparison between open surgery and endovascular repair

OBJECTIVES

to compare the inflammatory response following endovascular and conventional AAA repair.

DESIGN

prospective study.

PATIENTS AND METHODS

ten patients were selected for open surgery (OPEN) and ten for endovascular (ENDO) AAA repair. Leukocytes, platelets, myeloperoxidase, lactoferrin, beta-thromboglobulin, C-reactive protein (CRP), interleukin 6 (IL-6), tumour necrosis factor alpha (TNF-alpha) and complement activation products were measured before, during and after surgery.

RESULTS

in the OPEN group the median hospital stay was longer (6 vs. 12 days, p=0.001) and more patients required transfusion (p=0.02). IL-6 and CRP increased postoperatively, most in OPEN (p<0.01). Platelet counts decreased after the first angiography in ENDO (p<0.01) and before aortic cross-clamping in OPEN (p<0.05). The decrease was larger in OPEN (p=0.02). Leukocyte counts decreased after the first angiography in ENDO, and thereafter increased (p=0.001). An equivalent increase was observed in OPEN after declamping (p=0.001). Leukocyte and platelet degranulation products increased after the first angiography in ENDO and after declamping in OPEN. Changes in complement activation products were small. TNF-alpha did not change significantly.

CONCLUSION

endovascular AAA repair caused significant leukocyte and platelet activation. Based on the timing of activation this could be caused by radiographic contrast media.

Artificial juxtacrine stimulation for tissue engineering

To endow biomaterials with the ability to regulate cell functions such as proliferation, differentiation, and apoptosis, growth factor proteins were covalently immobilized. The proteins were immobilized on various matrices using different chemical methods. It was shown that insulin and epidermal growth factor stimulated cellular functions even after immobilization. Pattern-immobilization of growth factor proteins clearly demonstrated the stimulation by immobilized proteins. In other words, this type of stimulation by non-diffusional growth factors enabled us to regulate tissue formation with artificial biomaterials. The stimulation was enhanced by coimmobilization with adhesion factors. These stimulations due to the immobilized growth factors may mimic juxtacrine stimulation of membrane-anchored growth factors such as heparin-binding epidermal growth factor, transforming growth factor-alpha, and tumor necrosis factor-alpha.