Gastroschisis revisited: role of intraoperative measurement of abdominal pressure

Background

Animal studies have shown that visceral circulation is well preserved when intraabdominal pressure does not exceed 20 mm Hg. Our aim was to analyze the outcomes of a series of infants with gastroschisis whose surgical management was directed by the intraoperative measurement of bladder pressure.

Methods

Forty-two neonates with gastroschisis were surgically managed using intraoperative measurement of bladder pressure at a tertiary care center between July 31, 1992, and March 20, 2004, and their outcome was evaluated. Primary closure with or without prosthetic material was performed when pressures measured 20 mm Hg or less. Delayed closure using a silon pouch was performed when pressures measured more than 20 mm Hg. Categorical variables were analyzed including mode of delivery, associated anomalies, type of closure, complications, and mortality. Continuous variables were analyzed including gestational age, birth weight, bladder pressure, time to full feeds, and length of hospital stay. Categorical and continuous variables for both groups were compared using Fisher's Exact and Wilcoxon's rank-sum tests, respectively, and a significance level of .05 was used. Preapproval of this study was obtained from the Institutional Review Board (No. 6690).

Results

Thirty-three (79%) neonates with a mean bladder pressure of 16 mm Hg underwent primary closure and 9 neonates with a mean bladder pressure of 27 mm Hg underwent delayed closure with a silon pouch that was not spring loaded (P < .03). Patients treated with primary closure had faster return to full feeds and significantly shorter hospital length of stay compared with patients treated by delayed closure (P = .04). Surgical morbidity and mortality was nil in patients after primary closure. One patient with total abdominal evisceration died during attempted delayed closure and another patient required reoperation for bowel necrosis after delayed closure.

Conclusion

Primary closure was safely accomplished in 100% of neonates with gastroschisis whose bladder pressure measured 20 mm Hg or less. Further, this group of patients had a faster return to full feeds and a significantly shorter hospital length of stay compared with neonates who required delayed closure.     

Hyperoxaluria-induced oxidative stress and antioxidants for renal protection

Renal cellular exposure to oxalate (Ox) and/or CaOx crystals leads to the production of reactive oxygen species (ROS), development of oxidative stress followed by injury and inflammation. Renal injury and inflammation appear to play a significant role in stone formation. ROS are produced from many sources and involve a variety of signaling pathways. Tissue culture and animal model studies show that treatments with anti-oxidants and free radical scavengers reduce Ox/CaOx crystal induced injuries. In addition, CaOx crystal deposition in kidneys is significantly reduced by treatments with antioxidants and free radical scavengers, indicating their efficacy. These results point towards a great potential for the therapeutic application of antioxidants and free radical scavengers to reduce stone recurrence particularly after shock wave lithotripsy, which is itself known to generate ROS and cause renal damage.     

Citrate and vitamin E blunt the shock wave-induced free radical surge in an in vitro cell culture model

Free radical formation plays a major role in shock wave lithotripsy induced renal damage. Moreover, previous studies suggest that free radicals may also promote de novo calcium oxalate crystallization of previously damaged urothelium. Citrate is a known inhibitor of renal stone formation and has also been used as a free radical scavenger. Using an in vitro model with Madin-Darby canine kidney (MDCK) cells, we investigated the influence of two free radical scavengers, citrate and vitamin E, on the prevention of the shock wave-induced free radical surge. Suspensions of MDCK cells were placed in containers for shock wave exposure. Six groups of six containers each were examined: (a) no scavengers 0 shocks, (b) no scavengers 100 shocks, (c) citrate 0 shocks, (d) citrate 100 shocks, (e) vitamin E 0 shocks, (f) vitamin E 100 shocks. An unmodified HM3 was used to deliver 100 shocks at 24 kV. The cell groups that were not shocked acted as the control group and were handled identically, except for the lack of shock wave exposure. After shock wave administration, the containers were emptied and cell suspensions were immediately centrifuged. The supernatant was examined for lactate dehydrogenase (LDH) and 8-isoprostane (8-IP), markers of cellular injury and free radical formation, respectively. Intracellular LDH uniformly increased in all groups exposed to shock wave energy. Similarly, 8-IP increased in all shocked groups. However, the 8-IP increase was significantly reduced when the free radical scavengers were employed. As citrate is a well-known inhibitor of calcium nephrolithiasis, its mechanism of action may be further enhanced, based on its ability to reduce free radical formation, by a protective effect on the urothelium. These data further support the use of citrate based medications during the peri-operative period of shock wave lithotripsy, not only to inhibit stone formation and facilitate fragment passage, but also to reduce the incidence of shock wave induced renal damage. Further studies are warranted to clinically test this hypothesis.     

The biology of bone grafting

Many approaches are used to repair skeletal defects in reconstructive orthopaedic surgery, and bone grafting is involved in virtually every procedure. The type of bone graft used depends on the clinical scenario and the anticipated final outcome. Autogenous cancellous bone graft, with its osteogenic, osteoinductive, and osteoconductive properties, remains the standard for grafting. However, the high incidence of morbidity during autogenous graft harvest may make the acquisition of grafts from other sources desirable. The clinical applications for each type of bone graft are dictated by the structure and biochemical properties of the graft. An elegant cellular and molecular cascade follows bone transplantation. Bone graft incorporation within the host, whether autogenous or allogeneic, depends on many factors: type of graft (autogenous versus allogeneic, vascular versus nonvascular), site of transplant, quality of transplanted bone and host bone, host bed preparation, preservation techniques, systemic and local disease, and mechanical properties of the graft.     

Tamoxifen use in patients with ductal carcinoma in situ and T1a/b N0 invasive carcinoma

BACKGROUND: The purpose of this study was to determine how often patients with ductal carcinoma in situ and T1a/b N0 cancer are offered and accept tamoxifen for secondary chemoprevention. STUDY DESIGN: A retrospective review of 284 patients with T1a/b N0 invasive cancer treated between February 1995 and December 2001 and 129 patients with DCIS treated after September 1998 was carried out. Patient and tumor characteristics associated with being offered and accepting tamoxifen were compared. RESULTS: Tamoxifen was offered to 67% of the invasive cancer patients and accepted by 76% (51% of the entire group). Hormone receptor status was the only significant predictor of being offered tamoxifen (p = 0.004). Older age (p = 0.04), Caucasian race (p = 0.01), and parity (p = 0.04) in premenopausal women were significant predictors of tamoxifen acceptance on univariate analysis. After the publication of the National Surgical Adjuvant Breast and Bowel Project P-1 trial, significantly more patients were offered tamoxifen (p = 0.02), but acceptance rates did not change. Tamoxifen was offered to 91% of the ductal carcinoma in situ patients and accepted by 73% (67% overall). Lumpectomy was associated with significantly higher rates of being offered (p = 0.02) and accepting tamoxifen (p = 0.002) on univariate analysis. CONCLUSIONS: Factors associated with tamoxifen risks and benefits correlate poorly with the use of the drug.     

Awake surgery for glioma resection in eloquent areas--Zurich's experience and review--

Awake surgery was performed in a series of 21 patients with gliomas in eloquent areas with the use of intraoperative electrical mapping. Gross total removal was performed in 18 patients. There was no operative mortality. Postoperative findings included no change in symptoms and signs in 10 patients, improvement of the preoperative deficit in 11 patients. Four patients had improved Karnofsky performance status (KPS) scores after surgery, 17 patients were stable, and no patient had lower KPS score. Extensive radical resection of gliomas prolongs the overall survival and improves the patient's quality of life. However, surgical resection of gliomas located within the sensorimotor or language areas remains a neurosurgical challenge in reducing eloquent neurological sequelae. Awake surgery with intraoperative functional mapping is a safe approach to maximize the extent of tumor removal and to minimize the resultant neurological deficits in the treatment of glioma involving the eloquent cortex.