LAPAROSCOPIC AUGMENTATION CYSTOPLASTY WITH DIFFERENT BIODEGRADABLE GRAFTS IN AN ANIMAL MODEL:

Native extracellular matrix: a new scaffolding platform for repair of damaged muscle

Effective clinical treatments for volumetric muscle loss resulting from traumatic injury or resection of a large amount of muscle mass are not available to date. Tissue engineering may represent an alternative treatment approach. Decellularization of tissues and whole organs is a recently introduced platform technology for creating scaffolding materials for tissue engineering and regenerative medicine. The muscle stem cell niche is composed of a three-dimensional architecture of fibrous proteins, proteoglycans, and glycosaminoglycans, synthesized by the resident cells that form an intricate extracellular matrix (ECM) network in equilibrium with the surrounding cells and growth factors. A consistent body of evidence indicates that ECM proteins regulate stem cell differentiation and renewal and are highly relevant to tissue engineering applications. The ECM also provides a supportive medium for blood or lymphatic vessels and for nerves. Thus, the ECM is the nature's ideal biological scaffold material. ECM-based bioscaffolds can be recellularized to create potentially functional constructs as a regenerative medicine strategy for organ replacement or tissue repopulation. This article reviews current strategies for the repair of damaged muscle using bioscaffolds obtained from animal ECM by decellularization of small intestinal submucosa (SIS), urinary bladder mucosa (UB), and skeletal muscle, and proposes some innovative approaches for the application of such strategies in the clinical setting.

Laparoscopic augmentation cystoplasty: a comparison between native ileum and small intestinal submucosa in the porcine model

OBJECTIVES

To determine the feasibility of laparoscopic augmentation cystoplasty (LAC) in the porcine model and to compare LAC using standard bowel vs a small intestinal submucosa (SIS) allograft.

MATERIALS AND METHODS

Fourteen female pigs underwent LAC; six had standard ileal AC and eight AC with SIS. All the pigs had limited cystometrogram studies before surgery to determine bladder capacity. At 6 weeks after surgery the pigs were anaesthetized, the bladder capacities were re-assessed and then the pigs were killed; the bladders were harvested and examined histologically.

RESULTS

In all, 12 of 14 pigs completed the 6-week survival period; two pigs from the SIS group died from urinary ascites secondary to anastomotic leaks at the cystoplasty site. There were no complications in the ileal augmentation group. The operative duration was similar in both groups. The bladder capacities increased significantly in both groups, although more reliably in the native ileum group. In two pigs in the SIS group there was no increase in bladder capacity.

CONCLUSIONS

LAC is feasible in the porcine model and results in a significant increase in bladder capacity. AC using SIS does not appear to increase bladder capacity as reliably as native ileum, and has a higher complication rate.

Comparison of two laparoscopic suture patterns for repair of experimentally ruptured urinary bladders in normal neonatal calves

OBJECTIVE

To compare 2 laparoscopic suture patterns for repair of experimentally ruptured urinary bladders in normal neonatal calves.

STUDY DESIGN

Experimental surgical study.

ANIMALS

Thirty male Holstein calves.

METHODS

A bladder defect was created in 24 anesthetized calves (day 0). They were randomly divided into 4 groups (n=6/group). In groups 1 and 3, the defect was closed laparoscopically using a one layer full thickness simple continuous (FTSC) suture pattern (pattern A). In groups 2 and 4, the defect was closed laparoscopically in 2 layers using a FTSC suture pattern followed by Lembert continuous suture pattern (pattern B). Groups 1 and 2 calves were euthanatized at the end of the surgery and groups 3 and 4 at day 10. Six healthy calves were also euthanatized and used as a control group. The bladders were harvested and tested for bursting strength (BS). The surgical time (ST) data from the two groups for each pattern were pooled. A Student t-test was used to compare ST data. For the BS data, a 2-factor ANOVA test with post-hoc Student t-test was used to determine if treatment, time, or treatment-time interaction was significant. A Dunnett's test was used to compare BS of the 4 treatment groups to the control group. P<.05 was considered significant.

RESULTS

Mean ST was significantly shorter for pattern A than for pattern B. In all treatment groups, the mean bladder BS (MBBS) was significantly lower than the MBBS for the control group. The MBBS was significantly lower for group 1 than for group 2. There was no significant difference in the MBBS between groups 3 and 4.

CONCLUSION

In this study, a 1-layer laparoscopic closure technique had advantages compared with 2-layer laparoscopic closure technique. Further work is required before a 1-layer laparoscopic closure technique can be recommended clinically.

CLINICAL RELEVANCE

One-layer bladder closure is fast and safe in clinically normal calves and permits additional research to evaluate its safety in foals and clinical ruptures.