Traumatic Injury of the Superior Mesenteric Vein: Ligate,Repair or Shunt?

Abstract We report a case of SMV injury in a critically ill patient. The patient was a 19-year-old woman involved in a motor vehicle collision. Her injuries included grade II splenic and renal lacerations, devascularized and lacerated right and transverse colon, a transected transverse mesocolon, a massive shear injury of her abdominal wall, and two partial SMV transections. At initial damage control laparotomy, the SMV was ligated, the devascularized bowel resected and a temporary abdominal closure applied. At re-operation, a mesocaval shunt using saphenous vein was employed. The shunt failed and the patient required a saphenous vein jump graft. Although visceral vascular injuries are rare, ligation of the SMV in a damage control situation is acceptable. This case study is the first to discuss appropriate treatment when interruption to a patient's collateral visceral venous drainage limits the surgeon’s ability to ligate. In these situations, bypass shunts may be successful.     

Unicanalicular stent for nasolacrimal duct obstruction

The authors describe a method for silicone intubation of a single patent canaliculus associated with a nasolacrimal duct obstruction. Although bicanalicular intubation is always preferable when possible, unicanalicular stenting is necessary when only one canaliculus is patent. A chief advantage of this technique is that the lacrimal stent is inaccessible to the child and thus cannot be accidentally pulled out.     

Normal obstetric ultrasound reduces the risk of Down syndrome in fetuses of older mothers

The objective of this study is to determine whether a normal fetal morphology ultrasound scan in women older than 35 years reduces the risk of aneuploidy. We reviewed the results of amniocentesis and second trimester sonogram in all women older than 35 years from 1991 to 1995. None had prior screening. We excluded fetuses with structural anomalies. We determined the sensitivity and specificity of minor markers in detecting Down syndrome and also determined the reduction in risk of a normal sonogram. Among the 2060 women older than 35 years giving birth during the study period, 16 (0.78%) delivered an infant with Down syndrome. Of the 16 fetuses, two had no prenatal testing or ultrasound, two had invasive testing but no second trimester sonogram, five had a normal sonogram and seven had one or more sonographic markers of Down syndrome. At least 17% of women older than 35 years did not participate in prenatal testing or ultrasound. Ultrasound detected Down syndrome with a sensitivity of 59% (95% confidence interval: 45–72%), a false‐positive rate of 10.6% (9.4–11.8%) and a positive predictor value of 1 in 9. The likelihood of having normal karyotype if the sonogram was normal was 0.46 (0.31–0.61). In women older than 35 years, a normal second trimester sonogram reduces the risk of Down syndrome by more than 50%. At least 17% of women older than 35 years do not participate in prenatal testing or ultrasound.     

Stent fracture: an unusual cause of late restenosis after sirolimus-eluting stent placement.

Stent fracture is uncommon but may have consequences including restenosis. To date, stent fractures reported have been related to aggressive post dilation. We describe a case that involves fracture of a stent deployed to nominal pressure. Unlike most stent fractures reported that involve stent struts only our case demonstrated circumferential disruption with complete separation of the stent segments.     

Issues and challenges in staging of pressure ulcers.

Wound assessment is a key element of effective wound care, and assessment of pressure ulcers includes accurate determination of wound stage. Although the original staging system established by Shea was based on his understanding of the pathology involved in pressure ulcer development, subsequent staging systems (and the one currently in use) were intended simply to establish the level of tissue damage. Recently, clinicians have drawn attention to numerous limitations associated with the current staging system, including the inability to differentiate between an inflammatory response involving intact skin and a deep tissue injury (deep bruising) underneath intact skin. This is a clinically significant difference because clinicians have noted that most inflammatory responses resolve with intervention, whereas most areas of deep tissue injury progress to full-thickness ulcers even when appropriate intervention is provided. A second area of controversy involves partial-thickness (Stage 2) lesions; because many of these lesions are caused by maceration and/or friction (as opposed to pressure) clinicians are frequently unclear regarding which of these lesions should be staged. In response to these concerns, the National Pressure Ulcer Advisory Panel convened a consensus forum and published white papers to clearly outline the issues; they solicited clinician feedback on the white papers and the Wound, Ostomy, Continence Nurses Society provided a written response. This article summarizes the key points of the white papers, WOCN Society response, and consensus forum discussion.     

Subfractionation of human peripheral blood lymphocytes by partitioning in two-polymer aqueous phase systems. Characteristics of a small subpopulation of cells with high partition coefficient

Mixtures of aqueous solutions of dextran and poly(ethylene glycol) form immiscible 2-phase systems that are suitable for the separation of viable, functionally-competent cells on the basis of their surface properties. With the appropriate choice of ionic composition, these systems will separate cells on the basis of charge-related surface characteristics. We have previously shown that in charge-sensitive phase systems, human B lymphocytes have a low partition coefficient (K) and T cells have an intermediate K. The cell subpopulation with the highest K values contains large null lymphocytes that have most of the antibody-dependent and natural killer activities. The present study further characterizes this latter cell subpopulation. 8-33% of peripheral blood lymphocytes in normal persons had high K values. About 50% of these cells had typical Giemsa-staining granules characteristic of killer cells and one third had Fc receptors, but lacked complement receptors. Although 15-30% of the cells with high K values formed rosettes with sheep erythrocytes, there was virtually no response to T-cell mitogens such as PHA and Con A. Mixing cells having high K values with mitogen-responsive T cells from intermediate cell fractions revealed no evidence of suppressor-cell activity to explain the poor mitogen response. The studies indicate that a heterogeneous population of cells share charge-related surface properties resulting in a high partition coefficient. These cells comprise a significant proportion of human peripheral blood lymphocytes and include virtually all of the large granular lymphocytes as well as a large population without this morphology that shares the feature of unresponsiveness to T-cell mitogens.     

Increasing muscle strength as a treatment for strabismus: sustained release of insulin-like growth factor-1 in rabbit extraocular muscle.

PURPOSE: Currently, no drug treatment is available for strengthening underacting extraocular muscles (EOM) in strabismus. We showed previously that single injections of insulin-like growth factor (IGF-1) result in significant but short-term increases in muscle force generation. This study examined the effects of sustained release of IGF-1 on force generation in rabbit superior rectus muscles. METHODS: In adult rabbits, slow-release pellets containing IGF-1 were implanted on the global side of one superior rectus muscle. After 1 week, or 1, 2, 3, or 6 months, treated and control muscles were examined for force generation using an in vitro physiology apparatus. All muscles were prepared for histology and mean myofiber cross-sectional areas were determined. RESULTS: One and 3 months after pellet implantation, treated muscles generated significantly greater force than contralateral control muscles, whereas at 2 months, no significant difference was found. Force per cross-sectional area (mN/cm(2)) at 3 months also increased significantly in the treated muscles. Mean muscle cross-sectional area increased significantly after 1, 2, and 3 months of sustained exposure to IGF-1 compared with controls. After an additional 3 months without IGF-1 exposure, mean cross-sectional areas were significantly greater than controls but significantly reduced compared with areas at 1, 2, and 3 months. CONCLUSIONS: IGF-1 appears to be highly effective in increasing muscle force generation. Because slow release of IGF-1 results in sustained increases in EOM force generation, it may be a potentially useful alternative to surgical resection procedures because it avoids many of the potential long-term biomechanical hazards of resection surgery.