The Application of Split-Thickness Skin Graft as an Autogenous Arterial Conduit in a Goat (Capra Hircus) Model

Adequate autogenous vein is often the limiting factor in achieving a successful infrainguinal bypass. Attempts have been made to find alternative conduits; however, these alternatives have demonstrated inferior patency rates. We attempt to show that a split-thickness skin graft conduit provides a feasible autogenous arterial conduit. Neoconduits were prepared with an autogenous split-thickness skin graft (STSG) tubularized for a length of 5-6 centimeters with an appropriate caliber match to native artery. The deep dermal side of the graft was randomized to form either the external surface or the luminal surface. The neoconduit was placed as an interposition graft in the left common carotid artery. Grafts were studied in vivo with duplex ultrasonography and ex vivo by histopathology and immunohistochemistry. Feasibility study involved 4 animals with grafts harvested for study at 24 hours (n= 2) and 7 days (n= 2). Two subsequent groups were studied to evaluate 3-month (n= 8) and 6-month (n= 5) patency. All grafts (n= 4) in the feasibility phase of the study were patent at the time of harvest without evidence of aneurysmal degeneration. In the subsequent 8 goats, grafts with the deep dermal side forming the extraluminal surface (n= 4) had a propensity to ulcerate and rupture or to become aneurysmal (75%). The patency rate of these grafts at 6 weeks was 25%. In contrast, grafts with the deep dermal side forming the intraluminal surface (n= 4) demonstrated 75% patency at 6 weeks. Because of these results the remaining goats underwent placement of neoconduits with the deep dermal side forming the luminal surface. These grafts maintained a patency rate of 80% at 6 months. Neoconduits implanted with a diameter greater than 1.5 times the native arterial diameter became aneurysmal. Histopathology demonstrated neointimal formation in all grafts patent for longer than 7 days. Immunohistochemical staining for Factor VIII/von Willebrand’s factor (vWF) was reactive in the endoluminal cells of these grafts. Immunohistochemical staining for a-smooth muscle actin demonstrated reactivity in conduits patent for greater than 1 month. Split-thickness skin may provide a feasible source for autogenous conduit in arterial reconstructions and warrants further study. Technical factors affecting patency include orientation of the deep dermal surface of the STSG and the diameter of the neoconduit at the time of implantation.

Whipple disease: a case report and review of the literature

Whipple disease is a chronic, relapsing, and multisystem disease. It presents a diagnostic challenge for both clinicians and pathologists. Recent advances in isolation and culture have identified the organism responsible for the disease to be a member of the order Actinomycetes designated Tropheryma whipplei. Several immune system changes have been noted in patients with Whipple disease, but whether these are primary or secondary is as yet undetermined. Long-term antibiotic therapy is required, and relapses are common, especially with central nervous system involvement.

Mesenchymal dysplasia of the placenta

Placental mesenchymal dysplasia is a rare human placental disorder in which the placenta is enlarged and contains cystic villi and dilated vasculature. It is important to recognize this disorder because it may mimic a partial hydatidiform mole. In contrast to a partial mole, mesenchymal dysplasia may coexist with a normal fetus. This case occurred at the Madigan Army Medical Center in Tacoma, Washington, in June 2002.

Relationship between the extent of histologic villous mineralization and stillbirth in aneuploid and euploid fetuses

OBJECTIVE

To describe the relationship between the degree of placental histologic villous mineralization (VM) and stillbirth in aneuploid and euploid fetuses.

METHODS

The extent of VM for aneuploid and gestational age-matched euploid placentas was graded semiquantitatively on a 0 to 3 scale based on the number of terminal or stem villi containing mineralizations in forty x10 fields of view. The extent of VM was analyzed in relation to fetal status at delivery (liveborn or stillborn) for both aneuploid and euploid fetuses.

RESULTS

For 14 available aneuploid placentas, grade 0 or 1 VM was recorded for seven aneuploid specimens, of which two were stillborn. Grade 2 or 3 VM was recorded for seven aneuploid specimens, of which six were stillborn. Fourteen gestational age-matched euploid placentas served as controls. Grade 0 or 1 VM was observed in nine euploid specimens, of which four were stillborn. Grade 2 or 3 VM was observed in five euploid specimens, of which four were stillborn. For aneuploid fetuses, stillbirth was significantly more frequent with grade 2 or 3 VM compared with grade 0 or 1 VM (chi(2) = 4.667, P <.05). This relationship did not exist for euploid fetuses (chi(2) = 1.659, P >.05).

CONCLUSION

Histologic VM is not a universal finding in, or exclusive to, stillbirths. Aneuploid but not euploid stillbirths show increased histologic VM compared with livebirths. This may implicate impaired placental or circulatory function as a mechanism for death in aneuploid fetuses.