TABLE 3.

Histological Evaluation of Brain and Dura Treated With DuraGen XS, a Collagen Dural Substitute, or Hemopatch, a Polyethylene Glycol-Coated Collagen Dural Sealant and Substitute, 1, 8, and 16 wk After Implantation to Treat a 0.5-mm Diameter Durotomy (n = 8 per Time Point per Group)

	DuraGen XS			Hemopatch
Histopathology evaluation	1 wk	8 wk	16 wk	1 wk	8 wk	16 wk
Implant
Implant resorptiona	0.0 (0.0)	3.1 (0.4)	4.0 (0.0)	0.0 (0.0)	3.0 (0.8)	2.9 (0.8)
Response to implantb,c
Overall inflammation	1.0 (0.0)	0.0 (0.0)	0.0 (0.0)	1.0 (0.0)	0.0 (0.0)	0.0 (0.0)
Polymorphonuclear cells	0.3 (0.5)	0.0 (0.0)	0.0 (0.0)	0.8 (0.5)	0.0 (0.0)	0.0 (0.0)
Macrophages	1.0 (0.0)	0.0 (0.0)	0.0 (0.0)	1.0 (0.0)	0.0 (0.0)	0.0 (0.0)
Lymphocytes	0.1 (0.4)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)
Plasma cells	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)
Giant cells	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	1.0 (0.0)	0.0 (0.0)	0.0 (0.0)
Vacuolated macrophages	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.4 (0.5)	1.6 (0.5)	1.3 (0.5)
Fibrosis	1.0 (0.0)	1.6 (0.7)	1.6 (0.5)	0.3 (0.5)	1.8 (0.5)	1.9 (0.6)
Granulation tissue	1.0 (0.0)	0.0 (0.0)	0.0 (0.0)	1.4 (0.5)	0.0 (0.0)	0.0 (0.0)
Necrosis	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)
Vascularization	1.0 (0.0)	0.0 (0.0)	0.0 (0.0)	1.0 (0.0)	0.0 (0.0)	0.0 (0.0)
Foreign body response	0.0 (0.0)	0.0 (0.0)	0.1 (0.4)	1.0 (0.0)	0.0 (0.0)	0.0 (0.0)
Edema/hemorrhage	1.5 (0.5)	0.0 (0.0)	0.0 (0.0)	1.4 (0.5)	0.0 (0.0)	0.0 (0.0)
Bacteria presence	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)
Brain responsec
Gliosis	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.1 (0.4)	0.0 (0.0)
Neurodegeneration	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)
Adhesion: dura to pia/arachnoid	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.1 (0.4)	0.6 (0.5)	0.3 (0.5)
Inflammation: pia (durotomy), subacute	0.3 (0.5)	0.0 (0.0)	0.0 (0.0)	0.9 (0.4)	0.1 (0.4)	0.0 (0.0)
Hemorrhage	0.3 (0.5)	0.0 (0.0)	0.0 (0.0)	0.1 (0.4)	0.0 (0.0)	0.0 (0.0)
Necrosis	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)

^aImplant resorption scale grade 0: no implant resorption; grade 1: minimal resorption (<25%); grade 2: <50% resorption; grade 3: >50% resorption; grade 4: fully resorbed.

^bInflammatory cell scale grade 0: not present, none; grade 1: rare, estimated 1 to 5 cells per high-power field (phf), grade 2: mild, estimated 5 to 10 cells phf; grade 3: moderate, heavy infiltrate; grade 4: severe, packed cells.

^cAll other parameters. Grade 0: absent/none; grade 1: minimal, present but minimal feature; grade 2: mild, notable feature; grade 3: moderate; prominent feature that does not disrupt tissue architecture and is not overwhelming; grade 4: severe, overwhelming feature or feature that effaces or disrupts tissue architecture.

DuraGen XS degraded faster than Hemopatch. Tissues treated with Hemopatch had a greater number of vacuolated macrophage than DuraGen XS. Data presented as mean (standard deviation).