Tiam Mana Saffari

98 CHAPTER 5 Table 2. Long-term outcomes of vascular volume and vascular surface area. Values were expressed as the mean ± standard error of the mean. SIEF: superficial inferior epigastric fascial (SIEF) flap. Vascular volume Vascular surface area Control 12 wk 16 wk 5.0 ± 0.3 5.7 ± 0.3 26.0 ± 1.2 30.6 ± 1.1 Autograft 12 wk 16 wk 3.5 ± 0.4 5.0 ± 0.4 25.0 ± 2.8 28.1 ± 3.5 Allograft 12 wk 16 wk 2.7 ± 0.2 3.1 ± 0.2 18.0 ± 2.2 22.1 ± 1.7 SIEF 12 wk 16 wk 6.1 ± 1.5 12.6 ± 2.4 31.1 ± 2.2 37.6 ± 3.4 Revascularization patterns over time Starting at two weeks, vascularization consisting of a mesh-network occurred from both host stumps in nerve allograft and SIEF nerve samples, leaving the middle part avascularized. This invasion of microvessels was more evident from the proximal than from the distal end. Over time, these differences became more evident in the 12 and 16 week samples, as the sprouted vessels reached to the middle parts of the nerve. In nerve autografts, longitudinal running vessels were recognized that ran along the entire length of the nerve. These vessels appeared thicker compared to the newly formed vessels in the allograft and SIEF nerve samples. At 12 weeks, the proximal sections of the nerve samples showed that the addition of vascularization to allograft nerves (SIEF group) resulted in the highest number of vessels in the outer ring of the nerve (P<0.01). The SIEF group had significantly more vessels in the middle and central ring as well, compared to the allograft alone (P<0.05). In the mid-section of the nerve, the number of vessels in the allograft was lowest compared to all other groups in the middle ring (P<0.05). In the central ring, the allograft also measured the least number of vessels and was significantly inferior to SIEF nerves and control nerves (P<0.05). The number of vessels in SIEF nerves and control nerves were similar in the central ring of the mid-section of the nerve. In the distal section of the nerve, a trend towards a higher number of vessels was seen in