Optimal Solution Volume for Luminal Preservation: A Preclinical Study in Porcine Intestinal Preservation.

BACKGROUND: Rodent studies suggest that luminal solutions alleviate the mucosal injury and prolong intestinal preservation but concerns exist that excessive volumes of luminal fluid may promote tissue edema. Differences in size, structure, and metabolism between rats and humans require studies in large animals before clinical use. METHODS: Intestinal procurement was performed in 7 pigs. After perfusion with histidine-tryptophan-ketoglutarate (HTK), 40-cm-long segments were cut and filled with 13.5% polyethylene glycol (PEG) 3350 solution as follows: V0 (controls, none), V1 (0.5 mL/cm), V2 (1 mL/cm), V3 (1.5 mL/cm), and V4 (2 mL/cm). Tissue and luminal solutions were sampled after 8, 14, and 24 hours of cold storage (CS). Preservation injury (Chiu score), the apical membrane (ZO-1, brush-border maltase activity), and the electrolyte content in the luminal solution were studied. RESULTS: In control intestines, 8-hour CS in HTK solution resulted in minimal mucosal changes (grade 1) that progressed to significant subepithelial edema (grade 3) by 24 hours. During this time, a gradual loss in ZO-1 was recorded, whereas maltase activity remained unaltered. Moreover, variable degrees of submucosal edema were observed. Luminal introduction of high volumes (2 mL/mL) of PEG solution accelerated the development of the subepithelial edema and submucosal edema, leading to worse histology. However, ZO-1 was preserved better over time than in control intestines (no luminal solution). Maltase activity was reduced in intestines receiving luminal preservation. Luminal sodium content decreased in time and did not differ between groups. CONCLUSIONS: This PEG solution protects the apical membrane and the tight-junction proteins but may favor water absorption and tissue (submucosal) edema, and luminal volumes >2 mL/cm may result in worse intestinal morphology.

PREDISPOSANT FACTORS FOR INTIMAL HYPERPLASIA AND THEIR MECHANISMS OF ACTION IN OPEN VASCULAR SURGERY. A REVIEW.

BACKGROUND: Intimal hyperplasia is a multifactorial process that determines local stenosis and subsequent ischemia after revascularisation procedures. It is controlled by a plethora of cytokines, growth factors and proteases that interact through multiple mechanisms, empowering or inhibiting their hyperplasic action. Although the elements involved are the same, the resulted degree of vascular stenosis varies. METHODS: To highlight the predisposing conditions which enhance the vascular response to injury we consulted articles from Pubmed database, searching for the keywords "intimal hyperplasia", "neointimal hyperplasia" and "risk factor". RESULTS: 101 articles were included in the study. Risk factors analyzed are classified into local and systemic and the mechanisms by which they augment the process are explained. CONCLUSION: Knowledge of risk factors and their control when possible is a key element in increasing revascularization patency.

Infrarenal abdominal aorta approach through median minilaparotomy.

Classically, infrarenal aortic exposure is achieved by xyphopubic or xypho-infraumbilical laparotomy, in transperitoneal approach, or through a left abdominal incision, in retroperitoneal approach. The transperitoneal approach is associated with longer intestinal activity resumption time and incisional hernias on long term, due to intestinal extracavitary mobilization and long incision. These disadvantages disappear in laparoscopic approach, but this method is extremely laborious, requires an extended period for dissection, and elicits increased difficulty in performing the anastomosis on the aorta. The purpose of the study is to evaluate the infrarenal abdominal aorta approach through median minilaparotomy, a method that combines the excellent exposure of xypho-pubic incision with the low morbidity of laparoscopic approach. Between 07.01.2010 - 07.01.2011, we performed 37 revascularization surgeries in 36 patients with aorto-iliac occlusive disease (one patient required reintervention due to graft thrombosis), approaching the infrarenal aorta through median minilaparotomy. The sex distribution was 35 men and one woman. The average age was 61.1 years. There have been 25 aorto-bifemoral bypasses, 11 aorto-unifemoral bypasses, and one aorto-biiliac bypass. The mean aorta clamping time was 15 minutes. Average operating time was 150 minutes. We used 26 bifurcated Dacron prostheses and 11 linear ePTFEprostheses. The average intestinal activity resumption time was 32 hours. All patients included in the study were mobilized 24 hours after surgery. The average length of hospitalization was 7.7 days. 5 patients experienced complications during hospitalization and 3 patients suffered long term complications. Infrarenal abdominal aorta approach through median minilaparotomy is a viable alternative to conventional surgical techniques used in aortoiliac occlusive disease.