Cecal volvulus caused by internal herniation after roux-en-y gastric bypass surgery.

Cecal volvulus is the rotation of a mobile cecum resulting in a large bowel obstruction. We present the case of a 55-year-old female who underwent a roux-en-y gastric bypass in 2003 and presented to the emergency department with worsening abdominal pain, distention and obstipation. Roentgenogram demonstrated a 14 cm colon suggestive of sigmoid volvulus, but CT scan showed rectal contrast abruptly ending in the distal transverse colon, mesenteric swirling and a distended cecum, consistent with cecal, rather than sigmoid, volvulus. Upon surgical exploration the majority of the small bowel, cecum and ascending colon had herniated through the transverse mesocolon defect created during her prior gastric bypass. The bowel was reduced through the mesenteric defect, and an ileocecectomy was performed. This is, to our knowledge, the first reported case of cecal volvulus caused by an internal hernia through a mesocolon defect created during a prior roux-en-y gastric bypass operation.

Hyperacute Monocyte Gene Response Patterns Are Associated With Lower Extremity Vein Bypass Graft Failure.

BACKGROUND: Despite being the definitive treatment for lower extremity peripheral arterial disease, vein bypass grafts fail in half of all cases. Early repair mechanisms after implantation, governed largely by the immune environment, contribute significantly to long-term outcomes. The current study investigates the early response patterns of circulating monocytes as a determinant of graft outcome. METHODS: In 48 patients undergoing infrainguinal vein bypass grafting, the transcriptomes of circulating monocytes were analyzed preoperatively and at 1, 7, and 28 days post-operation. RESULTS: Dynamic clustering algorithms identified 50 independent gene response patterns. Three clusters (64 genes) were differentially expressed, with a hyperacute response pattern defining those patients with failed versus patent grafts 12 months post-operation. A second independent data set, comprised of 96 patients subjected to major trauma, confirmed the value of these 64 genes in predicting an uncomplicated versus complicated recovery. Causal network analysis identified 8 upstream elements that regulate these mediator genes, and Bayesian analysis with a priori knowledge of the biological interactions was integrated to create a functional network describing the relationships among the regulatory elements and downstream mediator genes. Linear models predicted the removal of either STAT3 (signal transducer and activator of transcription 3) or MYD88 (myeloid differentiation primary response 88) to shift mediator gene expression levels toward those seen in successful grafts. CONCLUSIONS: A novel combination of dynamic gene clustering, linear models, and Bayesian network analysis has identified a core set of regulatory genes whose manipulations could migrate vein grafts toward a more favorable remodeling phenotype.

The spectrum of hand dysfunction after hemodialysis fistula placement.

INTRODUCTION: Contemporary dogma has classically attributed hand dysfunction following hemodialysis arteriovenous fistula (AVF) placement to regional ischemia. We hypothesize that hemodynamic perturbations alone do not entirely explain the postoperative changes in hand function and, furthermore, that various elements of hand function are differentially affected following surgery. METHODS: Bilateral wrist and digital pressures and upper extremity nerve conduction tests were recorded preoperatively and at 6 weeks and 6 months following upper extremity AVF construction in 46 patients. Concurrently, biomechanical tests were administered to evaluate multiple limb functional domains including grip strength, dexterity, sensation and perception of hand function. RESULTS: Mean age was 59±14 years (75% male) and 48% were on hemodialysis at the time of access placement. 69% had a brachial-based AVF, and the remainder had radial-based accesses. Six weeks following AVF placement, a significant decrease in access side digital pressures was observed, with only partial recovery at 6 months (P<0.0001). Grip strength was significantly worse in the access side limb (P=0.0003), and Disability of Arm, Shoulder and Hand Questionnaire (DASH) score substantially worsened postoperatively (P=0.06). Digital sensation and limb dexterity did not differ between limb sides (P>0.1) or change significantly over time (P>0.1). Principal component analyses demonstrated that nerve conduction parameters tended to track the biomechanical parameters, yet both were relatively independent of the hemodynamic parameters. CONCLUSION: Our findings suggest that ischemia alone does not completely explain access-related hand dysfunction and that future study is needed to elucidate alternative mechanisms.

LPS Stimulation of Cord Blood Reveals a Newborn-Specific Neutrophil Transcriptomic Response and Cytokine Production.

BACKGROUND: The neonatal innate immune system differs to microbial infection both quantitatively and qualitatively when compared with adults. Here, we provide the first genome-wide ex-vivo expression profile of umbilical cord blood (UCB) neutrophils from full-term infants prior to and in response to whole-blood lipopolysaccharide (LPS) stimulation. Additionally, we provide cytokine expression prior to and following LPS stimulation. The genomic expression and cytokine profile are compared with LPS-stimulated whole blood from healthy adult subjects (HC). METHODS: Whole blood from UCB (n = 6) and HC (n = 6) was studied at baseline or was stimulated for 24 h with 100 ngs/mL of LPS. CD66b neutrophils were subsequently isolated with microfluidic techniques and genome-wide expression analyses were performed. Ingenuity Pathway Analysis (IPA) software was utilized to predict downstream functional effects. Additionally, cytokine concentrations in whole blood prior to and after 24 h of LPS incubation were determined. RESULTS: LPS stimulated whole blood from UCB demonstrated significant differences in both ex-vivo cytokine production and PMN gene expression. Mixed-effect modeling identified 1,153 genes whose expression changed significantly in UCB and HC after exposure to LPS (P < 0.001 with a minimum 1.5-fold change). IPA downstream predictions suggest that PMNs from UCB fail to effectively upregulate genes associated with activation, phagocytosis, and chemotaxis in response to LPS stimulation. Furthermore, whole blood from UCB showed increased interleukin (IL)-10 production to LPS, but failed to significantly increase several pro-inflammatory cytokines. CONCLUSIONS: LPS-stimulated whole blood from UCB exhibited a markedly suppressed inflammatory cytokine production and PMN innate immune genome response. These differences in gene expression and cytokine production may be an adaptive response to a prior fetal environment, but may also explain their increased susceptibility to infections. Characterization of these deficits is the first step toward developing prophylactic and therapeutic interventions.