Processed bovine pericardium as patch angioplasty for carotid endarterectomy: a preliminary report

Selection criteria for patch angioplasty material in carotid endarterectomy

Background:

Carotid endarterectomy (CEA) with patch angioplasty has been favored due to its lower reoccurrence of restenosis compared to primary CEA. There are multiple types of patch angioplasty material available. However, selection of patch material is based on uncertain criteria. The aim of this study is to determine the ideal criteria for selecting the best patch material for CEA.

Methods:

We conducted a comprehensive literature search for studies that describe the ideal criteria for selecting patch material for CEA. We compiled all of the criteria mentioned into one table and selecting the criteria which were most frequently mentioned with a simple scoring system.

Results:

A total of 65 studies out of 784 studies were assessed for its full-text eligibility. Thus, we found 23 studies that were eligible for analysis. There are 22 ideal criteria that were mentioned in the analyzed studies. We grouped these criteria into physical characteristics, safety, contribution to hemodynamic, contribution in tissue healing, economic aspect, and ability to prevent postsurgical complication. We proposed 10 ideal criteria for guiding vascular surgeon in selecting the best patch angioplasty material.

Conclusion:

To this day, no material has been discovered which meets all ten criteria. This study’s proposed ideal criteria serve as the foundation for the creation of the best patch angioplasty material.

In vivo endothelialization and neointimal hyperplasia assessment after rabbit carotid endarterectomy with bovine pericardium

Background

Previous studies have reported that the use of a patch in carotid endarterectomy (CEA) surgery can reduce the rate of restenosis and perioperative complications. The goal of this study was to compare the short- and medium-term outcomes of endothelialization and neointimal hyperplasia of patch closure (PC) angioplasty in CEA with direct closure (DC) in a rabbit model. A bovine pericardial patch (BPP) was used in the PC procedures.

Methods

Two carotid arteries were dried by air flow to simulate endarterectomy and selected for PC and DC in each rabbit. Different animals were sacrificed at 1, 2, 3, 4, and 8 weeks after the procedure. The endarterectomized segments were extracted and examined microscopically with histopathological and immunohistochemical analysis, and electron-microscopy measurements.

Results

In all, 19 rabbits were included in this study; 3 rabbits were placed in a 2-week postoperative group and 4 rabbits were placed in the 1-, 3-, 4-, and 8-week postoperative group respectively. Hematoxylin-eosin (HE) staining showed neointima on the PC side at an early stage (1-week postoperatively), and intimal hyperplasia could be seen on both sides. Immunohistochemical analysis showed that Ki-67 was higher on the PC side than on the DC side at an early stage (1,661.5±1,122.9 cells/mm², P=0.060). In the 2-week postoperative group, von Willebrand factor (vWF) was higher on the DC side (−377.0±155.6 cells/mm², P=0.052). Alpha-smooth muscle actin (α-SMA) values were comparable on both sides (P>0.05). Electron microscopy measurements showed that functional endothelial cells exhibited a cobblestone-like morphology and were nicely elongated in the direction of blood flow.

Conclusions

The use of BPP in PC angioplasty during CEA can maintain stability and also provide rapid endothelialization. PC with BPP has comparable ability of efficient endothelialization with DC, but is more likely to have early endothelialization.

Outcomes of carotid endarterectomy in the Vascular Quality Initiative based on patch type

OBJECTIVE

The Vascular Quality Initiative (VQI) is the largest registry of vascular surgical procedures and as such is capable of distinguishing small but important differences in outcomes. The goal of this study was to determine the outcomes of carotid endarterectomy (CEA) based on patch type, including bovine pericardium, autogenous vein, polytetrafluoroethylene (PTFE), and Dacron.

METHODS

All primary CEAs performed with primary repair and patching (n = 70,987) within the VQI were retrospectively analyzed. Reoperative CEA and combined CEA and coronary artery bypass were excluded. Rates of any postoperative neurologic event, return to the operating room (bleeding, neurologic event, or wound complication), and restenosis (>50% and >80%) at 1-year follow-up were primary outcomes. Rates were compared by patch type using χ² and Bonferroni analysis. Multivariate hierarchical logistic regression models were used to predict end points of postoperative neurologic event, return to the operating room, and 1-year restenosis.

RESULTS

During the period of study, 2003 to 2017, there were 70,987 CEAs entered into the VQI registry. Bovine pericardium was the patch material with the highest frequency of use (n = 51,480), followed by Dacron (n = 12,356), vein (n = 1460), and PTFE (n = 1638). Bovine pericardium, vein, and Dacron had lower rates of postoperative neurologic events compared with PTFE or primary repair. Bovine pericardium had the lowest rate of restenosis at 1 year. By multivariate analysis, bovine pericardium (odds ratio [OR], 0.70; 95% confidence interval [CI], 0.56-0.89) and protamine use (OR, 0.74; 95% CI, 0.60-0.91) were associated with a lower incidence of return to the operating room. The use of Dacron, vein, and PTFE patches was not significantly different from the reference of primary closure. Multivariate analysis of postoperative neurologic events revealed that bovine pericardium (OR, 0.59; CI, 0.48-0.72) and Dacron (OR, 0.56; CI, 0.43-0.72) were associated with lower incidence of stroke or transient ischemic attack, whereas vein and PTFE were no different from primary closure. Bovine pericardium (OR, 0.57; CI, 0.44-0.75), Dacron (OR, 0.70; CI, 0.50-0.98), vein (OR, 0.72; CI, 0.53-0.98), and never smoking (OR, 0.87; CI, 0.78-0.96) were associated with a lower incidence of restenosis at 1 year by multivariate analysis.

CONCLUSIONS

Bovine pericardium has superior outcomes both postoperatively and at 1 year compared with other patch materials. The large volume of patient data contained in the VQI makes it possible to compare outcomes that have small but meaningful differences.

Durability of Carotid Endarterectomy with Bovine Pericardial Patch

BACKGROUND

Multiple studies have shown that patch angioplasty after carotid endarterectomy (CEA) reduces the risk of stroke and restenosis when compared with primary closure. Biological, synthetic, or vein patches have been traditionally used in CEA. This article reports the early and long-term outcomes of bovine pericardium (BP) for patch angioplasty in CEA.

METHODS

A retrospective, consecutive analysis of 874 patients who underwent CEA during the past 17 years at Mayo Clinic, Florida, was performed. BP patch (BPP) was used in 680 patients. Other CEA techniques were used in 194 patients (standard without patch, 78; standard with Dacron, 74; standard with vein patch, 16; and other techniques: bypasses, 26). We defined group 1 as those who underwent BPP angioplasty and group 2 as those who underwent all other techniques. Early and late clinical outcomes and patch-related complications (restenosis, infection, and hematoma) were recorded and analyzed.

RESULTS

Median follow-up for the entire series was 39.6 months. There were no statistically significant differences in 30-day mortality and morbidity between the 2 groups, except that BP group has less 30-day stroke (0.1%, 1 of 680) versus other techniques (1.5%, 3 of 194, P = 0.03). Thirty-day postoperative mortality rate was 0.1% (1 of 680) in BPP group and 1.0% (2 of 194) in other technique group (P = 0.13). No statistically significant difference was noted in 30-day postoperative major complications (transient ischemic attack [TIA], wound infection, hematoma requiring surgical evacuation, and nerve injury) between the 2 groups. Ten-year freedom from stroke/TIA were 97.8% in the BP group compared with 98.5% in the other group (P = 0.86). Ten-year freedom from restenosis was also similar between groups (89.0% BP vs. 90.4% others, P = 0.69). Ten-year survival rate was 38.4% in BP group and 45.0% in other technique group, and this was statistically significant on univariate analysis only.

CONCLUSIONS

CEA with BP angioplasty has excellent early and late outcomes with minor morbidity and mortality.

Use of the vascu-guard bovine pericardium patch for arteriotomy closure in carotid endarterectomy. Early and long-term results

BACKGROUND

To report the early and long-term results of Vascu-Guard bovine pericardium (BP) for patch angioplasty in carotid endarterectomy (CEA).

METHODS

We retrospectively analyzed the data of 256 CEAs with BP patch closure performed in 238 patients during the past 12 years in our department. Patch-related complications (restenosis, infection, and aneurysm formation) and early and late (12 to 144 months follow-up) clinical outcomes were recorded and statistically analyzed.

RESULTS

Thirty-day postoperative stroke rate was 1.2% (3/256) with zero mortality. Major complications occurred in 3.5% (9 of 256) of the procedures and cranial nerve injury in 4.3% (11 of 256). At 12 years, cumulative estimates of freedom from any stroke, stroke-free survival, and freedom from restenosis were 88.4% (standard error [SE]: 3.3%), 60% (SE: 7.8%), and 98.3% (SE: 0.8%), respectively. No patient experienced patch infection or aneurysm formation.

CONCLUSIONS

This series shows the efficacy, safety, and durability of CEA with BP patch closure, in both the short and long term. BP combines the advantages of vein and synthetic patches, representing a suitable option when performing CEA.

Establishing a swine model to compare vascular prostheses in a contaminated field

OBJECTIVE

Patch arteriotomies are performed during many vascular procedures. Whereas synthetic materials are generally felt to be inappropriate for infected environments, the suitability of glutaraldehyde-treated bovine pericardium (GBP), a biologic material, in such instances is unknown. Our main objectives were to develop an animal model to study vascular prostheses while comparing the infectability of polyester (Dacron) and GBP in a topically infected environment.

METHODS

Twenty-three pigs underwent transabdominal patch arteriotomy of the infrarenal aorta with either Dacron or GBP. The patches were inoculated with sterile saline (1 per group), Staphylococcus aureus 10(4) colony-forming units (CFUs) (4 per group), or S. aureus 10(5) CFUs (6 per group). At 3 wk, the animals were euthanized, and the patches were removed via a left retroperitoneal approach. Specimens were collected for microbiologic and histologic analysis.

RESULTS

One animal from each group inoculated with 10(5) CFUs died during the study period, and another died immediately postoperatively of an airway complication. All aortas were patent and without evidence of pseudoaneurysm formation. Gross abscesses were found in 4/6 Dacron and 5/6 GBP animals receiving 10(5) CFUs. Similarly, 4/6 animals implanted with Dacron and 5/6 animals implanted with GBP had positive tissue cultures. A histologic grading system of inflammation substantiated the culture results.

CONCLUSIONS

No significant difference exists between Dacron and GBP to resist bacterial infection at 3 wk. We have established a reproducible in vivo model to study arterial patch materials in a topically infected environment.

Intermediate-term outcome of carotid endarterectomy with bovine pericardial patch closure compared with Dacron patch and primary closure

OBJECTIVE

Multiple studies have established that patch angioplasty following carotid endarterectomy (CEA) reduces the risk of subsequent stroke and restenosis compared with primary closure. Previous reports have also demonstrated bovine pericardium to be associated with similar rates of postoperative complications and restenosis compared with other patch materials. Due to favorable handling and sonographic properties, bovine pericardium has become increasingly popular as a patch option in recent years. However, the intermediate- and long-term performance of this material remains incompletely defined. Through a retrospective analysis of our carotid endarterectomy experience, we sought to compare the bleeding, infection, and pseudoaneurysm rates with bovine pericardium patch closure to those with Dacron patch and primary closure. In this study, 1331 primary carotid endarterectomies performed in our institution between 1996 and 2008 were grouped according to the method of arteriotomy closure: primary closure (PC) (216, 16.3%), Dacron patch angioplasty (DPA) (642, 48.2%), and bovine pericardial patch angioplasty (BPA) (457, 34.3%). Demographic variable and postoperative outcome measures collected real-time via a designated database manager were assessed by univariate and multivariate analysis.

RESULTS

Mean follow-up for the entire cohort was 46.1 months. There were no statistically significant differences in rates of postoperative wound infection, hematoma, pseudoaneurysm formation, or 30-day stroke or 30-day mortality among the three groups. Combined 30-day stroke and death was significantly lower in the PC cohort (0.5% vs 2.3% DPA vs 2.4% BPA; P = .94, BPA vs DPA; P = .001, BPA vs PC; P = .001, DPA vs PC), while 5-year restenosis after both DPA (2.0% ± 0.6%) and BPA (1.1% ± 0.6%) was significantly lower compared with PC (5.2% ± 1.6%) (P = .03, DPA vs PC; P = .008, BPA vs PC; P = .14, BPA vs DPA). Five-year survival following BPA (77.9% ± 3.6%) was significantly improved compared with PC (66.9% ± 3.5%) and DPA (60.8% ± 2.1%) in univariate analysis (P = .24, DPA vs PC; P = .01, BPA vs PC; P = .03, BPA vs DPA), with statin use (P = .004) and male gender (P = .05) being positive predictors of enhanced survival on multivariate analysis.

CONCLUSIONS

This single-institution, retrospective review represents the largest reported experience with BPA after CEA to date and is the only report comparing outcomes after BPA to PC or to DPA. Our experience further demonstrates that patch angioplasty is protective against restenosis after CEA compared with PC. Equivalent rates of perioperative bleeding, infection, and pseudoaneurysm formation were seen with each closure strategy in this study.

Resistência tensional do pericárdio bovino fixado em glutaraldeído comparada com a da veia safena magna

CONTEXTO: O uso do pericárdio bovino como remendo na endarterectomia de carótida é uma alternativa à veia safena magna. As vantagens do pericárdio incluem facilidade de obtenção, menor tempo operatório e principalmente menor índice de ruptura. OBJETIVO: Avaliar a resistência tensional do pericárdio bovino tratado com glutaraldeído e compará-la com a da veia safena magna. MÉTODOS: Os remendos de pericárdio bovino (grupo I, n = 20) e de veia safena magna (grupo II, n = 20) foram recortados em dimensões iguais (50 x 5 mm) e preparados de modo habitual a sua utilização. Os grupos foram submetidos a ensaio de tração e comparados em relação a força de ruptura, força máxima e tensão de ruptura utilizando-se o teste t de Student. A correlação da espessura do remendo com a força de ruptura também foi analisada utilizando-se o coeficiente de correlação linear de Pearson. RESULTADOS: Os parâmetros força de ruptura e força máxima foram significativamente maiores no grupo dos remendos de pericárdio bovino: 1,97 versus 1,36 kgf (p = 0,001230) e 2,27 versus 1,51 kgf (p = 0,0001087), respectivamente. A tensão de ruptura média para o material pericárdio bovino também foi maior (193,99±43,05 versus 49,19±22,96 kgf/cm², p = 7,603e-16) do que na veia safena. A correlação entre a espessura e a força de ruptura foi considerada moderada (r = 0,5032993) para o pericárdio bovino e baixa (r = 0,3062166) para o grupo da veia safena. CONCLUSÃO: Os autores concluem que a resistência do pericárdio bovino à ruptura foi considerada adequada neste estudo, e é significativamente maior que a da veia safena magna, retirada da região da coxa. Além disso, a espessura do remendo em ambos os grupos não apresenta boa correlação com sua resistência a ruptura.

Carotid Endarterectomy with Bovine Pericardium Patch Angioplasty: Mid-Term Results

The objective of this study was to assess the efficacy of bovine pericardium (BP) as a patch material in carotid endarterectomy (CEA) in terms of peri- and postoperative complications and the incidence of recurrent stenosis. During a 4-year period, 148 CEAs were performed in 138 consecutive patients. The study group included elective, emergency, and combined with cardiac operation CEAs in both symptomatic and asymptomatic carotid artery disease patients. Patch angioplasty using the BP followed the standard CEA in all patients. Postoperative follow-up included clinical examination and periodical color duplex scans at 3, 6, and 12 months and yearly thereafter. Surgical outcome was evaluated by the operation-related parameters, early and late mortality and morbidity rates, and the incidence of recurrent stenosis. All CEAs were performed without any unfavorable event. In the early postoperative period, there were no deaths and the morbidity consisted of transient cranial nerve paresis (4.7%) in seven patients and two ipsilateral strokes (1.4%). During the follow-up period, three patients (2%) developed significant carotid restenosis, though they remain asymptomatic, while there were no deaths related to the CEA. Patch angioplasty of the carotid artery using BP showed unwittingly early and mid-term surgical outcome. Our results demonstrate the BP to be a suitable patch material for routine use in carotid surgery.

Antero-axillary access for hypoplastic aortic arch repair

A 16-year-old adolescent presented with systemic hypertension due to a hypoplasia of the aortic arch resulting in a significant stenosis. In childhood, he underwent surgery for aortic coarctation through a left posterolateral thoracotomy. We present the successful repair of the complete aortic arch that could be achieved applying a patch plasty of bovine pericardium through an anteroaxillary thoracotomy.

Hydroxyapatite implant wrapping materials: analysis of fibrovascular ingrowth in an animal model

PURPOSE

To compare the influence of seven currently available spherical orbital implant wraps on host fibrovascularization of a hydroxyapatite (HA) orbital implant.

METHODS

Five groups of 3 (15 total) adult male New Zealand albino rabbits underwent enucleation with placement of a 12-mm HA implant wrapped in high-porosity expanded polytetrafluoroethylene (e-PTFE), processed bovine pericardium, or processed human pericardium, sclera, or fascia lata. Magnetic resonance imaging before and after the intravenous administration of gadolinium-diethylenetriamine pentaacetic acid (DTPA, 0.1 mol/kg) was performed immediately before exenteration. Five rabbits (one with each of the different implant wraps) were killed at 4, 8, and 12 weeks, and the operated socket was exenterated. Histopathologic sections of the implants were then compared with the results of our previous study using polyglactin 910 mesh and autologous sclera as HA orbital implant wraps.

RESULTS

Complete fibrovascularization of all the implants occurred by 12 weeks; however, HA implants wrapped with sclera, polyglactin mesh, and e-PTFE appeared to undergo more rapid fibrovascularization than spheres wrapped with other materials.

CONCLUSIONS

Although all of the implant wraps studied may be suitable substitutes for donor sclera, we prefer polyglactin mesh because it is readily available, inexpensive, and without risk of transmissible diseases.