Benefits and Risks of Prophylactic Cerebrospinal Fluid Catheter and Evoked Potential Monitoring in Symptomatic Spinal Cord Ischemia Low-Risk Thoracic Endovascular Aortic Repair

Background To assess risks and benefits of a standardized strategy to prevent symptomatic spinal cord ischemia (SSCI) after thoracic endovascular repair (TEVAR) using routine cerebrospinal fluid (CSF) catheter placement and evoked potential (EP) monitoring.

Methods One hundred and ninety-five patients underwent 223 SSCI low-risk TEVAR procedures between 1998 and 2014. CSF catheter was used to measure CSF pressure and drain CSF if necessary throughout the procedure and up to 24 hours thereafter. EPs were used to monitor spinal cord integrity throughout the procedure.

Results Underlying pathologies included descending thoracic aortic aneurysm in 115 (52%), type B aortic dissection in 85 (38%), traumatic aortic rupture in 16 (7%), and others in 7 (3%) patients. CSF catheter was inserted before TEVAR in 116 procedures (52%). Active CSF draining was required in 29 patients (25%). The CSF catheter caused no major and 11 (10%) minor complications. EP were monitored during 88 (40%) procedures. We observed a reduction in the amplitude, prolonged latencies, or complete signal loss in nine procedures. There were no EP monitoring-related complications. SSCI incidence was higher in patients without CSF drainage (0.8% vs 4.7%, p = 0.031).

Conclusion Use of CSF drainage is associated with a significant lower incidence of SSCI after SSCI low-risk TEVAR than nonuse, whereas the complication rate associated with CSF drainage insertion or removal is very low. Routine EP monitoring is a useful tool to detect immediate arterial inflow obstruction to the spinal cord. The combination of these two methods serves as a safe and reliable standardized strategy in reducing the incidence of SSCI to a minimum.

Surgical Treatment of Native and Prosthetic Aortic Infection With Xenopericardial Tube Grafts

BACKGROUND

The study sought to report our results of surgical treatment of native and prosthetic aortic infection with xenopericardial tube grafts from the ascending aorta to beyond the bifurcation.

METHODS

Within a 28-month period, 20 patients were treated with a bovine self-made pericardial tube graft to replace infected vascular grafts (after conventional surgical aortic replacement or endovascular stent graft implantation) or to treat a contaminated surgical site. An integrated standardized therapeutic concept was applied in all patients, consisting of complete removal of the infected prosthetic material, extensive debridement, and orthotopic vascular reconstruction with self-made tube grafts constructed from a bovine pericardial patch.

RESULTS

Four patients died perioperatively (20%) due to sepsis, pulmonary failure, or sudden circulatory arrest. The mean follow-up was 18 months (first quartile 2, third quartile 17 months). Interval computed tomography scans revealed 100% freedom from proven aortic reinfection, but reinfection cannot be ruled out in 4 patients who died of unknown causes during follow-up or because of ongoing sepsis. Three patients required aortic reintervention for a suture-line aneurysm, for graft occlusion, and for the development of a neoaortointestinal fistulation, respectively.

CONCLUSIONS

Patients with infectious aortic disease present in a frail state and the initial and the late mortality is substantial. Yet, surgical treatment of native and prosthetic aortic infection with xenopericardial tube grafts shows promising short-term results with regard to durability and freedom from reinfection in any aortic segment. Further studies are needed to learn of the long-term behavior of these grafts.

Endovascular treatment of acute Type A aortic dissection-the Endo Bentall approach

Outcome after classical surgical repair of acute Type A aortic dissection has steadily improved over the years and several modifications in cannulation and perfusion added to this achievement. However, subgroups remain where results of classical surgical repair still have room for improvement, particularly patients with severe preoperative malperfusion as well as elderly patients with a limited physiological reserve. So far, only small case series or case reports have been published on the endovascular treatment of dissected ascending aortas. However, a tube alone is not sufficient to fix the entire complex underlying problem in the vast majority of patients with acute Type A aortic dissection. In addition, these published reports are either due to a favorable anatomy or due to very localized disease processes, which are the exception and not the rule. The concept of an endovascular valve-carrying conduit may significantly increase the number of patients suitable for endovascular therapy and it may soon be common practice.

Chronic type B "residual" after type A: what I would do?

"The major goal of surgery for acute type A aortic dissection is to have an alive patient." This motto still remains the most important directive. However, also depending onto the extent of the underlying pathology and consecutively depending onto the extent of primary surgery, there is and will be need for additional classical surgical or interventional treatment sooner or later during follow-up in a substantial number of patients having had surgery for acute type A aortic dissection. This article shall guide the interested reader through the underlying mechanisms as well as treatment options in patients with chronic type B "residual" after type A repair and shall finally suggest preventive strategies to reduce the occurrence of this pathology to a minimum.

Local and Lower Limb Complications during and after Femoral Cannulation for Extracorporeal Life Support

Objective The extracorporeal life support system (ECLS) system is a lifesaving option for patients in pulmonary and/or cardiac failure. We reviewed our data on local complications in the leg and groin during and after ECLS explantation.

Methods Patients were included when an ECLS was cannulated in the groin and the ECLS was successfully weaned and explanted. Data were collected retrospectively in patients from January 2013 to January 2016.

Results In this study, 90 patients were included; 39 (43%) ECLS were implanted with surgical cut down and 51 (57%) ECLS were implanted percutaneously. Most patients needed ECLS support following cardiac surgery: cut down: 25 (64%) versus percutaneous: 28 (55%) (p = 0.40). A distal leg perfusion cannula was implanted simultaneously in 61 (68%) patients (cut down: 25 [64%] vs. percutaneous: 36 [71%], p = 0.36). Distal leg ischemia was diagnosed in a total of 10 (11%) patients (cut down: 2 [5%] vs. percutaneous: 8 [16%], p = 0.18). Of those 10 patients, 5 patients had leg ischemia despite a distal leg perfusion cannula in place (cut down: 1 [3%] vs. percutaneous: 4 [8%], p = 0.38). Revascularization was successfully achieved in all patients and no amputations had to be performed. Similar rates of wound healing disorders were observed in both groups: cut down: 11 (28%) versus percutaneous: 10 (20%) patients (p = 0.45).

Conclusion Surgical and percutaneous implantation and explantation of ECLS are safe and feasible with comparable complication rates, including wound healing disorders. We recommend that a lower limb perfusion cannula should be placed to prevent leg ischemia. Surgical cut-down placement of the distal leg perfusion cannula may reduce the incidence of distal leg ischemia compared with percutaneous distal leg cannula implantation. Correct placement of the cannula should be controlled.

Spinal Ischemia in Thoracic Aortic Procedures: Impact of Radiculomedullary Artery Distribution

BACKGROUND

The aim of this study was to assess the influence of thoracic anterior radiculomedullary artery (tARMA) distribution on spinal cord perfusion in a thoracic aortic surgical model.

METHODS

Twenty-six pigs (34 ± 3 kg; study group, n = 20; sham group, n = 6) underwent ligation of the left subclavian artery and thoracic segmental arteries. End points were spinal cord perfusion pressure (SCPP), regional spinal cord blood flow (SCBF), and neurologic outcome with an observation time of 3 hours. tARMA distribution patterns tested for an effect on end points included (1) maximum distance between any 2 tARMAs within the treated aortic segment (0 or 1 segment = small-distance group; >1 segment = large-distance group) and (2) distance between the end of the treated aortic segment and the first distal tARMA (at the level of the distal simulated stent-graft end = group 0; gap of 1 or more segments = group ≥1).

RESULTS

The number of tARMA ranged from 3 to 13 (mean, 8). In the large-distance group, SCBF dropped from 0.48 ± 0.16 mL/g/min to 0.3 ± 0.08 mL/g/min (p < 0.001). We observed no detectable SCBF drop in the small-distance group: 0.2 ± 0.05 mL/g/min at baseline to 0.23 ± 0.05 mL/g/min immediately after clamping (p = 0.147). SCBF increased from 0.201 ± 0.055 mL/g/min at baseline to 0.443 ± 0.051 mL/g/min at 3 hours postoperatively (p < 0.001) only in the small-distance group.

CONCLUSIONS

We demonstrate experimental data showing that distribution patterns of tARMAs correlate with the degree of SCBF drop and insufficient reactive parenchymal hyperemia in aortic procedures. Individual ARMA distribution patterns along the treated aortic segment could help us predict the individual risk of spinal ischemia.

Descendo-bifemoral bypass grafting and renal artery revascularization to treat complex obliterative arteriopathy

OBJECTIVES

Our goal was to describe a new standardized approach in patients with extensive obliterative arteriopathy aimed at distal revascularization and surgical kidney recruitment via descendo-bifemoral bypass grafting and renal artery revascularization.

METHODS

Three patients with Leriche's syndrome and either a compromised single kidney or unilateral significant renal artery stenosis were treated with a standardized surgical approach, restoration of distal perfusion via descendo-bifemoral bypass with synchronous ( n  = 2) left-sided renal artery revascularization or metachronous ( n  = 1) right-sided renal artery revascularization.

RESULTS

The intended surgical aim was achieved successfully in all 3 cases. All patients showed a decline in serum creatinine levels. One patient who needed substitution therapy was free from dialysis 3 months after surgery. Additionally, blood pressure management was substantially reduced because uncontrolled peak systolic episodes were no longer observed and pharmacotherapeutic agents could be partially withdrawn.

CONCLUSIONS

Distal revascularization and surgical kidney recruitment via descendo-bifemoral bypass and renal artery revascularization is a promising option to treat complex obliterative arteriopathy.

Generalized Malperfusion Due to Systemic Embolization From a Large Thrombosed Pulmonary Vein Aneurysm

We report the case of a 61-year-old patient who presented with generalized malperfusion due to systemic embolization from a large, partially thrombosed aneurysm of the left upper pulmonary vein. When the patient arrived at our center, large thrombus formations were detected in the left atrium and the abdominal aorta, as well as the renal, iliac, and femoral arteries. Renal, splenic, and mesenteric ischemia was diagnosed with computed tomography. The patient was in shock, acute kidney failure, and in high vasopressor need. The case highlights the risk of intraluminal thrombus formation in pulmonary vein aneurysms and underlines the need for systemic anticoagulation therapy and surgical therapy, if diagnosed in time.

Fenestrated and Branched Aortic Grafts

BACKGROUND

Abdominal and thoracic aortic aneurysms are diagnosed in 40 and 10 to 15 out of 100 000 persons per year, respectively. Fenestrated (fEVAR) and branched (bEVAR) stent grafts have been developed for abdominal juxtarenal and thoracoabdominal aneurysms. We discuss the patency and complication rates of fEVAR and bEVAR procedures and compare them with the outcome of open surgery.

METHODS

This review is based on pertinent publications from 2011 to 2014 that were retrieved by a selective literature search. The clinical outcomes of case series involving a total of more than 1500 patients are presented. The discussion takes account of recommendations contained in the literature and the authors' own experience.

RESULTS

Open surgery and aortic stent grafting have not been compared in any randomized trial to date. We identified 7 clinical series that included a total of 1270 fEVAR patients and 5 with a total of 408 bEVAR patients. The perioperative mortality after fEVAR procedures was 0-4%. Spinal cord ischemia arose in 1% of cases. The stent patency rate in visceral vessels ranged from 93 to 98%. bEVAR procedures were associated with both higher mortality (4-7%) and more common spinal cord ischemia (4-13%). 5-8% of all patients needed dialysis perioperatively, and the stent patency rate in visceral vessels was 94-97%. Preoperative renal insufficiency was a risk factor for peri-interventional death. Impaired renal function after fEVAR/bEVAR procedures was mainly associated with intermittent lower limb ischemia.

CONCLUSION

The results of fEVAR/bEVAR procedures in the last 5 years are similar to those of open surgery. The high postoperative rate of spinal cord ischemia remains a serious problem in the endovascular treatment of thoracoabdominal aortic aneurysms. The decision to implant a stent graft by an endovascular approach or to treat surgically should be made on a case-to-case basis in an interdisciplinary vascular conference.

Ablation of biglycan attenuates cardiac hypertrophy and fibrosis after left ventricular pressure overload

AIMS

Biglycan, a small leucine-rich proteoglycan, has been shown to play an important role in stabilizing fibrotic scars after experimental myocardial infarction. However, the role of biglycan in the development and regression of cardiomyocyte hypertrophy and fibrosis during cardiac pressure overload and unloading remains elusive. Thus, the aim of the present study was to assess the effect of biglycan on cardiac remodeling in a mouse model of left ventricular pressure overload and unloading.

METHODS AND RESULTS

Left ventricular pressure overload induced by transverse aortic constriction (TAC) in mice resulted in left ventricular dysfunction, fibrosis and increased biglycan expression. Fluorescence- and magnetic-assisted sorting of cardiac cell types revealed upregulation of biglycan in the fibroblast population, but not in cardiomyocytes, endothelial cells or leukocytes after TAC. Removal of the aortic constriction (rTAC) after short-term pressure overload (3weeks) improved cardiac contractility and reversed ventricular hypertrophy but not fibrosis in wild-type (WT) mice. Biglycan ablation (KO) enhanced functional recovery but did not resolve cardiac fibrosis. After long-term TAC for 9weeks, ablation of biglycan attenuated the development of cardiac hypertrophy and fibrosis. In vitro, biglycan induced hypertrophy of neonatal rat cardiomyocytes and led to activation of a hypertrophic gene program. Putative downstream mediators of biglycan signaling include Rcan1, Abra and Tnfrsf12a. These genes were concordantly induced by TAC in WT but not in biglycan KO mice.

CONCLUSIONS

Left ventricular pressure overload induces biglycan expression in cardiac fibroblasts. Ablation of biglycan improves cardiac function and attenuates left ventricular hypertrophy and fibrosis after long-term pressure overload. In vitro biglycan induces hypertrophy of cardiomyocytes, suggesting that biglycan may act as a signaling molecule between cell types to modulate cardiac remodeling.

Selective Heart, Brain and Body Perfusion in Open Aortic Arch Replacement

Open aortic arch replacement is a complex and challenging procedure, especially in post dissection aneurysms and in redo procedures after previous surgery of the ascending aorta or aortic root. We report our experience with the simultaneous selective perfusion of heart, brain, and remaining body to ensure optimal perfusion and to minimize perfusion-related risks during these procedures. We used a specially configured heart-lung machine with a centrifugal pump as arterial pump and an additional roller pump for the selective cerebral perfusion. Initial arterial cannulation is achieved via femoral artery or right axillary artery. After lower body circulatory arrest and selective antegrade cerebral perfusion for the distal arch anastomosis, we started selective lower body perfusion simultaneously to the selective antegrade cerebral perfusion and heart perfusion. Eighteen patients were successfully treated with this perfusion strategy from October 2012 to November 2015. No complications related to the heart-lung machine and the cannulation occurred during the procedures. Mean cardiopulmonary bypass time was 239 ± 33 minutes, the simultaneous selective perfusion of brain, heart, and remaining body lasted 55 ± 23 minutes. One patient suffered temporary neurological deficit that resolved completely during intensive care unit stay. No patient experienced a permanent neurological deficit or end-organ dysfunction. These high-risk procedures require a concept with a special setup of the heart-lung machine. Our perfusion strategy for aortic arch replacement ensures a selective perfusion of heart, brain, and lower body during this complex procedure and we observed excellent outcomes in this small series. This perfusion strategy is also applicable for redo procedures.

Multicentre analysis of current strategies and outcomes in open aortic arch surgery: heterogeneity is still an issue

OBJECTIVES

The study was conducted to evaluate, on the basis of a multicentre analysis, current results of elective open aortic arch surgery performed during the last decade.

METHODS

Data of 1232 consecutive patients who underwent aortic arch repair with reimplantation of at least one supra-aortic artery between 2004 and 2013 were collected from 11 European cardiovascular centres, and retrospective statistical examination was performed using uni- and multi-variable analyses to identify predictors for 30-day mortality. Acute aortic dissections and arch surgeries not involving the supra-aortic arteries were not included.

RESULTS

Arch repair involving all 3 arch arteries (total), 2 arch arteries (subtotal) or 1 arch artery (partial) was performed in 956 (77.6%), 155 (12.6%) and 121 (9.8%) patients, respectively. The patients' characteristics as well as the surgical techniques, including the method of cannulation, perfusion and protection, varied considerably between the clinics participating in the study. The in-hospital and 30-day mortality rates were 11.4 and 8.8% for the entire cohort, respectively, ranging between 1.7 and 19.0% in the surgical centres. Multivariable logistic regression analysis identified surgical centre, patient's age, number of previous surgeries with sternotomy and concomitant surgeries as independent risk factors of 30-day mortality. The follow-up of the study group was 96.5% complete with an overall follow-up duration of 3.3 ± 2.9 years, resulting in 4020 patient-years. After hospital discharge, 176 (14.3%) patients died, yielding an overall mortality rate of 25.6%. The actuarial survival after 5 and 8 years was 72.0 ± 1.5% and 64.0 ± 2.0, respectively.

CONCLUSIONS

The surgical risk in elective aortic arch surgery has remained high during the last decade despite the advance in surgical techniques. However, the patients' characteristics, numbers of surgeries, the techniques and the results varied considerably among the centres. The incompleteness of data gathered retrospectively was not effective enough to determine advantages of particular cannulation, perfusion, protection or surgical techniques; and therefore, we strongly recommend further prospective multicentre studies, preferably registries, in which all relevant data have to be clearly defined and collected.

Two Aortic Ruptures in Two Months-Role of Cross-Clamp-Associated Late Injury

BACKGROUND

Aortic cross-clamping may lead to iatrogenic tissue damage resulting in immediate or later aortic dissection or rupture.

METHODS

We report on a patient with an acute type B aortic dissection with mega-aortic syndrome whose aorta ruptured twice within 2 months.

RESULTS

The second aortic rupture occurred at the level of prior cross clamping. The pressure along the clamp jaws is distributed unequally. According to the law of the lever, the aortic area near the hinge is under more stress than the aortic area distal to the hinge. Unequal pressure distribution may injure the aorta.

CONCLUSIONS

There is a need to evaluate pressure distribution along the various currently available aortic clamp jaws and to develop the perfect aortic clamp providing equal pressure distribution designed especially to clamp large aortas or those of patients with connective tissue disorders.

Unequal pressure distribution along the jaws of currently available vascular clamps: do we need a new aortic clamp?

OBJECTIVES

The pressure along vascular clamp jaws may be unequally distributed, with greater pressure near the clamp hinge than at its top. Such unequal pressure distribution may cause aortic injury, especially in large aortas. We evaluated pressure distribution along different currently availably clamp jaws.

METHODS

Seven descending thoracic aortas from pigs (diameter 2.0-3.0 cm) were plainly dissected and all side arteries closed. Aortas were filled up with water and cross-clamped. The pressure inside the aorta was raised to 100 mmHg and the aorta was clamped so tightly that no water exited from the distal aortic end. Each aorta was clamped seven times at different sites with the following clamps: DeBakey, Satinsky, femoral, iliac, Chitwood, angled handle Fogarty and straight handle Fogarty. The pressure along the clamp jaws was measured with a pressure-detecting film placed between the clamp jaws and aorta. The collagen-fibre disorganization was examined in haemotoxylin-eosin- and Elastica van Gieson-stained tissue samples.

RESULTS

The DeBakey clamp revealed the lowest maximum pressure along the clamp jaws after complete aortic occlusion (1.43 ± 0.49 MPa), whereas the Chitwood clamp's pressure was the highest (3.26 ± 1.93 MPa, P < 0.001). The angled handle Fogarty clamp displayed the lowest difference between maximum pressures across the jaws (33%), with the greatest difference measured in the iliac (72%) and Chitwood (66%) clamps. The highest collagen-fibre disorganization score was observed in the proximal-to-the-clamp-hinge quartile after clamping with the angled handle Fogarty (2.8 ± 0.4), straight handle Fogarty (2.3 ± 0.8) and Chitwood (2.3 ± 0.5) clamps.

CONCLUSIONS

The pressure along clamp jaws is unequally distributed in all the currently available vascular clamps. The Chitwood clamp is associated with the highest maximum pressure during complete aortic occlusion and with the most unequal pressure distribution along the jaws.

Secondary organ fistulation after thoracic endovascular aortic repair

This manuscript describes the mechanisms behind aorto-oesophageal fistulation (AOF) and aortobronchial/pulmonary (ABPF) fistulation after TEVAR, reports the therapeutical approaches and defines recommendations how to prevent these complications in the future.

Biomechanical analysis of wrapping of the moderately dilated ascending aorta

BACKGROUND

External wrapping is a surgical method performed to prevent the dilatation of the aorta and to decrease the risk of its dissection and rupture. However, it is also believed to cause degeneration of the aortic wall. A biomechanical analysis was thus performed to assess the stress of the aortic wall subjected to external wrapping.

METHODS

A stress analysis using the finite elements method was carried out on three models: a non-dilated aorta, a moderately dilated aorta and a wrapped aorta. The models were subjected to a pulsatile flow (120/80 mmHg) and a systolic aortic annulus motion of 11 mm.

RESULTS

The finite elements analysis showed that the stress exerted on the outer surface of the ascending aorta in the wrapping model (0.05-0.8 MPa) was similar to that observed in the normal aorta (0.03-0.7 MPa) and was lower than in the model of a moderately dilated aorta (0.06-1.4 MPa). The stress on the inner surface of the ascending aorta ranged from 0.2 MPa to 0.4 MPa in the model of the normal aorta, from 0.3 to 1.3 MPa in the model of the dilated aorta and from 0.05 MPa to 0.4 MPa in the wrapping model.

CONCLUSIONS

The results of this study suggest that the aortic wall is subjected to similar stress following a wrapping procedure to the one present in the normal aorta.