Mild anorexia, general inactivity was seen in all the animals after 2-3 days of surgical reconstruction; however, they recovered and seemed active and alert by 10th post-surgical day. None of the animal developed any sign of persistent inflammatory reaction, chronic pain, scar formation, suture sinuses, wound infection, wound dehiscence or herniation. The skin wounds in all the animals were completely healed as recorded on 10th post-surgical day and external stitches were removed. The changes of clinical parameters and gross evaluation of the surgical wound (Table 1) revealed that the rectal temperature (°C), heart rate (beat/minute) and respiration rate (rate/minute) were increased significantly on 3rd day in all the groups; however it was non-significant between the groups which indicates that biomaterial implant
i.
e. ACP and APP imparts little or no immediate effects on body clinical parameters. The post-surgical elevation of clinical parameters might be attributed to surgical pain, post-surgical fever and swelling. In agreement with the author’s findings
Nath (2018) recorded similar changes in clinical parameters in pigs in application of biomaterial for surgical reconstruction of abdominal wall. The gross evaluation of surgical wound revealed highest scores
viz. degree of swelling, exudation, warmth and pain on 3
rd day following operation; however, the changes remained non-significant between the groups. The gross changes of the surgical wound might be due to host tissue reaction as well as surgical stress. Similar observation was also noticed by
Kumar et al., (2013) in goats with acellular dermal matrix and
Abass et al., (2008) in sheep after correction of umbilical hernia using bovine tunica vaginalis. The changes in the haemato-biochemical parameters have been depicted in Table 2. There was mild decrease in blood haemoglobin concentration in all the groups on 10th post operative day, which might be due to blood loss during surgery.
Munoz et al., (2015) stated that decrease of blood haemoglobin is of multifactorial origin following surgery.
Kumar et al., (2016) observed significant decline of haemoglobin level on day7 following fracture corrections in goat. There was mild level fall of PCV in all the groups on 10
th day which was insignificant between the groups. It indicates that use of different biomaterial had a trifling effect on packed cell volume. A contemporaneous fall in blood haemoglobin concentration and regarded as post operative anaemia as discussed by
Babu et al., (2014); Munoz et al., (2015) and
Shander (2016). The elevated PCV on 20
th and 30
th might be due to regenerative action of haemopoetic system. TLC increased significantly in Group A and B and non-significantly in Group C on10
th postoperative day which returned to normalcy towards the end. This could be due to local inflammatory reaction following surgical trauma. Similar findings were observed by
Fazio et al., (2015) in bitch and cat;
Kumar et al., (2016) in goats. In all the Groups the serum alkaline phosphatase (ALP) showed significant elevation on 10
th day which returned gradually in subsequent observations. This might be attributed to ubiquitous nature of the enzyme as well as acute wound healing involves type III collagen formation. In agreement with the author’s findings
Vimalraj (2020) also mentioned ALP expression during hard tissue healing and inflammation. The magnitude of increase in enzyme activity in Group A and B was more as compared to Group C which could be due to extra cellular matrix regulated ALP induction. Similar observation recorded by
Vimalraj (2020) hard tissue healing. In contrary,
Arun et al., (2015) mentioned that there is an acute decrease in plasma ALP activity after brain injury. The total serum protein in all the animals exhibited significant elevation on 10
th day following surgical reconstruction; however the values decreased on 20
th and 30
th day. There was non-significant difference of the values between control and treated groups might be attributed to comparative tissue reaction to xenograft. In accordance to the author’s observation
Munthe-Kaas et al., (2018) recorded elevated serum total protein level in correction of inguinal hernia in pig. A state of hyperglycemia was developed in all the animals on 10th day after operation followed by declined significantly on 20
th day and reached to base value on 30
th day. This might be attributed to surgical trauma and metabolic stress response. The authors findings also supported by
Duncan (2012).
The wounds were reopened on 10
th, 20
th and 30
th post-surgical day in order to record the gross changes of the surgical site, implanted tissue, surrounding host tissue reaction, adhesions and the degree of incorporation of the engrafted biomaterial with the host tissue. In Group C the abdominal suture was slenderly palpable and moderately palpable in the other two groups on 10th post surgical day (Fig 5, 6 and 7). Mild adhesion of the grafted tissue viscera was seen in Group B which was easily separable (Fig 8). Moderate adhesion was recorded between biomaterial and omentum in Group A, which was comfortably separated by blunt dissection (Fig 9). On contrary, there was no adhesion noticed in Group C (Fig 10). On 20thpost-surgical day in Group A, the abdominal suture was inconspicuously detectable with the outline (Fig 11); there was also mild adhesion with visceral organs (Fig 12). In group B the sutures were no more visible although the outline of the pericardium matrix was clear; the host tissue proliferation towards the engrafted tissue was clearly visible without abdominal adhesion (Fig 13). On the other hand, in Group C there was complete integration between the graft and native tissue, abdominal suture was feebly visible with a mild elevation over the surgical knot without any adhesion (Fig 14). On 30th post-operative day significant host tissue proliferation over the biomaterial and fibroplasias with fuzzy line of demarcation without any adhesion was seen in Group A (Fig 15). In Group B the matrix was entirely concealed by host tissue proliferation without any visceral adhesion (Fig 16). Group C animals exhibited completely normalized abdominal wall with no traces of abdominal suture line and visceral adhesion (Fig 17). The initial mild to moderate visceral adhesion found resolved automatically in tested groups as observed on 30th day was also supported by findings of
Singh et al., (2008) in rabbits with biomaterial application and
Nath et al., (2022) in rabbits with synthetic mesh application.
On 10
th day, the histopathological examination of the implanted graft revealed early signs of neovasculariztion with cellular infiltration (Fig 18) in Group C and B (Fig 19); while in Group A there were polymorphonuclear, mononuclear and fibroblast cellular infiltration (Fig 20). Fibrosis with marked angiogenesis was recorded on 20
th day in Group C (Fig 21), which was well organized in Group A (Fig 22) and remained nearly unchanged in Group B (Fig 23). A mild degree of cellular infiltration along with neovascularization in all the groups was recorded till 30
th day of examination (Fig 24). Cellular infiltration of polymorph nuclear cells, mononuclear cells and fibroblasts was observed in all the groups in entire experiment however highest was in Group A long with angiogenesis and fibrosis. This indicates that acellular caprine pericardium is well suited for integration with host tissue. The author’s findings were in accordance with the observation of
Singh et al., (2008) after abdominal reconstruction with porcine bladder, diaphragm and dermal matrix in rabbits at day 7.
Doria et al., (2018) found that inflammatory reaction had mostly subsided by 180 days after surgical repair of abdominal wall defects.
