Hernia recurrence after laparotomy: how to close an incised light-weight mesh?

A rising number of patients require relaparotomy after implantation of mesh materials for incisional hernia (IH) repair. No published recommendation concerning how to close the incision in a surgical mesh exists. We describe a central IH recurrence through a partly absorbable mesh positioned in the retromuscular plane 16 months after laparotomy due to a small bowel ileus. This recurrence was repaired using a heavy-weight, monofilament polypropylene mesh, again in the retromuscular position. Reducing the amount of nonabsorbable material in large pore hernia meshes leads to markedly reduced scar formation rather than the formation of a thick scar plate. Once cut and resutured, this scar may be too weak to withstand the mechanical strain, giving rise to a 'blow-out' IH recurrence, as demonstrated in our case. In these cases, re-enforcement with a nonabsorbable, small, porous polypropylene mesh in the retromuscular space is feasible and leads to the development of a mechanically stable scar.

Intravascular volume depletion in a 24-hour porcine model of intra-abdominal hypertension.

BACKGROUND: The purpose of the study was to examine hemodynamic parameters and intravascular volume in a porcine model in the presence of intra-abdominal hypertension (IAH) lasting for 24 hours. METHODS: Twelve pigs (52.5 +/- 4.9 kg) were studied over a period of 24 hours. In six animals, the intra-abdominal pressure was increased to 30 mm Hg via carbon dioxide-pneumoperitoneum. The others served as controls. Using the double-indicator dilution technique, intrathoracic blood volume (ITBV), total circulating blood volume, and cardiac output (CO) were measured. Standard parameters (e.g., central venous pressure [CVP]), were also recorded. RESULTS: In the presence of IAH, ITBV and total circulating blood volume were significantly reduced to 55% and 67% of control values. CO decreased to 27% and CVP increased fourfold. CONCLUSION: IAH leads to significant intravascular volume depletion that is not reflected by the CVP. Assessment of CO and ITBV in the presence of a critically increased intra-abdominal pressure is therefore recommended.

Evaluation of two novel methods for the direct and continuous measurement of the intra-abdominal pressure in a porcine model.

OBJECTIVE: Intravesical bladder pressure (IVP) measurement is considered to be the gold standard for the assessment of intra-abdominal pressure (IAP). However, this method is indirect, discontinuous, and potentially infectious and relies on a physiological bladder function. This study evaluated two novel methods for direct, continuous IAP measurement. DESIGN AND SETTING: Experimental study in an animal research laboratory. SUBJECTS: 18 male domestic pigs. INTERVENTIONS: CO(2) was insufflated to increase the IAP to 30 mmHg for 18 and 24 h in six animals each. Another six animals served as controls. A piezoresistive (PRM) and an air-capsule (ACM) pressure measurement probe were placed intra-abdominally and of IAP was measured every 1 h (PRM/ACM) or every 2 h (IVP). The mean difference between insufflator readings and IAP values and limits of agreement (mean difference +/-2 SD) were calculated. MEASUREMENTS AND RESULTS: In the presence of applied pressure IVP and PRM remained significantly below insufflator readings while ACM values showed no difference. Mean difference (and limits of agreement) were 4.5 (-2.1 to 11.1 mmHg), 1.6 (-8.0 to 11.2 mmHg), and 0.5 (-4.5 to 5.4 mmHg) for IVP, PRM, and ACM. The mean measurement-to-measurement drift of the ACM values was 9.0+/-10.2 mmHg. CONCLUSIONS: In this model agreement of PRM and ACM with insufflator readings was comparable to IVP. As both methods may be advantageous regarding continuous straightforward measurement of IAP, the employment in further experimental and clinical investigations is suggested.