Tissue Expansion

Jose R. Colombo, Jr., Osamu Ukimura, and Inderbir S. Gill

Section of Laparoscopic and Robotic Surgery, Glickman Urological Institute, Cleveland Clinic Foundation, Cleveland, Ohio, U.S.A.

PATHOPHYSIOLOGY

Laparoscopic Augmentation

VISCERAL TISSUE EXPANSION IN URINARY

Ureterocystoplasty

TRACT

RESULTS

DESAI STUDY

CLINICAL STUDY

Percutaneous Insertion of Ureteral

CLINICAL IMPLICATIONS

Expansion Balloon

REFERENCES

Chronic Ureteral Expansion

Chronic Ureteral Expansion

Tissue substitutes for reconstructive procedures of the urinary bladder, such as augmentation cystoplasty, are needed in a variety of acquired and congenital pediatric and adult urological diseases. Amongst the various self-tissue substitutes such as buccal mucosa, scrotal skin, pericardium, or allograft tissues, which can be used for a variety of urologic reconstructive procedures, only vascularized intestinal segments have been successful as regards reconstructive surgery of the urinary bladder (1-5). However, use of intestinal segments in urinary tract reconstruction is associated with significant potential disadvantages, including metabolic complications, complicated infections, stone and tumor formation, and a variety of surgical risks associated with bowel surgery (1). These disturbances are exaggerated in patients with compromised renal function, and in children.

Currently, various vascularized intestinal segments are most commonly used as tissue substitutes for bladder augmentation.

Although it is difficult to estimate the total number of surgical cases performed in the United States, in which such excessive substitute tissue is needed, a recent article from a single pediatric hospital reported their experience with 483 cases of bladder augmentation during 25 years (6). The disadvantages of using intestinal segments in urinary tract reconstruction include metabolic changes, mucus production, high incidence of early and late surgical complications, and stone/tumor formation (1). These disturbances may be exaggerated in patients with compromised renal function, and in children. In a search for more suitable tissue for bladder reconstruction, a variety of sources have been explored (1-5,7). The majority of these sources are still considered experimental, lacking any meaningful long-term clinical or experimental follow-up results.

Chronic tissue expansion is an established concept for creating new tissue in plastic surgery. Expansion of native skin has been successfully employed in various surgical disciplines such as breast reconstruction, craniofacial surgery, and plastic reconstructive surgery in patients with extensive burns (8). The expanded, new tissue, created by chronic stretch, replicates the morphometric and functional characteristics of the native tissue. A large body of literature has been accumulated to explore the mechanisms involved in tissue expansion in response to chronic stretch. This literature demonstrates that the mechanisms behind the principle of stretch-induced cellular growth involve a network of several integrated cascades that include growth factors, extracellular, cytoskeletal and transmemberane structures, ion channels; protein kinases, second messenger systems; and transcriptional factors (9-29).

This multifaceted network is initiated by a mechanical stimulus that sets into play a series of precise reactions through what has been referred to as the stretch-induced signal transduction pathway (9).

Currently, various vascularized intestinal segments are most commonly used as tissue substitutes for bladder augmentation.

Chronic tissue expansion is an established concept for creating new tissue in plastic surgery.

This multifaceted network is initiated by a mechanical stimulus that sets into play a series of precise reactions through what has been referred to as the stretch-induced signal transduction pathway.

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