Fluid perfused urethral pressure profilometry and Valsalva leak point pressure: a comparative study in a biophysical model of the urethra

In patient studies the correlation between maximum urethral closure pressure (MUCP) and Valsalva leak point pressure (LPP) is meagre at best (r = 0.22–0.50). We therefore studied the relation between MUCP and LPP in a flexible and extensible model urethra. We applied differently sized pressure zones and different degrees of resistance to a biophysical model urethra by stepwise inflating three types of blood pressure cuff placed around the model. At each degree of resistance we measured detrusor LPP, an in vitro equivalent of Valsalva LPP. Subsequently, we recorded the Urethral Pressure Profile using a water-perfused 5F end-hole catheter at four withdrawal rates and five perfusion rates and calculated MUCP. We tested the dependence of LPP on pressure zone length and MUCP on perfusion rate, withdrawal rate and pressure zone length using analysis of variance. We tested the correlation between LPP and MUCP using Pearson’s correlation coefficient and Linear Regression. LPP did not significantly depend on the pressure zone length (P = 0.80) and increased linearly with increasing cuff pressure. MUCP also increased with increasing cuff pressure, however, MUCP significantly depended (P < 0.01) on perfusion rate, withdrawal rate and pressure zone length. MUCP increased with increasing perfusion rate, and decreased with increasing withdrawal rate. In our model urethra MUCP only accurately reflected urethral resistance for a very limited number of combinations of perfusion rate and withdrawal rate. LPP reflected urethral resistance independent of the type of pressure zone.     

Primary revision of mid-vein stenoses in venous bypass conduits: venous patch versus interposition vein

PURPOSE: Patients after infrainguinal vein bypasses are a group at risk of graft stenosis and occlusion. Revision of failing grafts has been shown to significantly improve bypass patency and limb salvage. Options for surgical revision of mid bypass stenosis includes either patch angioplasty (PA) or interposition grafting (IG). We reviewed our experience with surgical revision of vein bypass stenosis. METHODS: From April 1968 to March 2006, 7557 autogenous vein bypasses were performed at Albany Medical Center and its affiliated institutions, of these 316 required single or multiple revision of vein grafts with patch angioplasty or interposition vein grafting. Excluded were proximal and distal anastomotic revisions. Only 235 bypasses had single revisions as either patch angioplasty (n = 108) or interposition grafting (n = 127) and are the focus of this review. The initial bypass revisions in these two groups are analyzed for indications, clinical parameters, operative strategies, and long-term patencies and clinical outcomes. RESULTS: There were no significant differences in mean age, gender, or frequency of comorbid conditions (coronary artery disease, pulmonary disease, hypertension, and diabetes) between the two patient groups. Secondary patency of patch angioplasty revision at 5 years was 79%. Patencies for interposition grafting revision at 5 years were equivalent to patch angioplasty group at 75%. When bypasses were evaluated on the basis of initial reconstructions (ie, in situ vs excised vein bypass), the results showed that in situ bypasses that required initial revision had similar 5-year patencies when interposition grafting was used as the first revision strategy vs patch angioplasty (80% vs 73%). Excised vein bypasses had similar patency when patch was their first revision strategy vs interposition grafting (4 year secondary patency 92% vs 75% respectively). CONCLUSION: Autogenous vein bypasses are at risk for developing significant stenosis and occlusion with time. Bypass stenosis that develops in the main body of the graft can be effectively repaired using either patch angioplasty or interposition grafting. Depending on the host of other factors, such as availability of autogenous venous conduit, location of stenosis, accessibility for operative repair, and the patient's anatomic characteristics, either operative strategy is effective in prolonging the patency of the bypass.     

Anorectal stimulation causes increased colonic motor activity in subjects with spinal cord injury

BACKGROUND: Difficulty with evacuation (DWE) is a major problem after spinal cord injury (SCI). Stimulation of the anal canal and lower rectum, accomplished using a gloved finger (so-called digital rectal stimulation or DRS) is often used as an adjunct to laxatives and enemas to facilitate bowel evacuation. However, the basis for the efficacy of DRS is not known. This study assessed the effect of DRS on colonic motility. METHODS: Six subjects with SCI were studied several hours after a bowel care session. Colonic motility was assessed using a manometric catheter (affixed endoscopically to the splenic flexure) at baseline, during DRS, and after DRS. In addition, evacuation of barium oatmeal paste (with the consistency of stool and introduced into the rectum and descending colon) was assessed simultaneously using fluoroscopic techniques. RESULTS: The mean number (+/- SEM) of peristaltic waves per minute increased from 0 at baseline to 1.9 (+/- 0.5/min) during DRS and 1.5 (+/- 0.3/min) during the period immediately after cessation of DRS (P < 0.05). The mean amplitude (+/- SEM) of the peristaltic contractions was 43.4 (+/- 2.2) mmHg. The frequency of contractions, as well as amplitude of contractions, during or immediately after DRS was not significantly different. These manometric changes in response to DRS were accompanied by expulsion of barium oatmeal paste in every subject by the fifth DRS. CONCLUSIONS: DRS causes left-sided colonic activity in subjects with SCI. At least in part, an anorectal colonic reflex that results in enhanced contractions of the descending colon and rectum may contribute to bowel evacuation in individuals with SCI.     

The promise of stem cell therapy to restore urethral sphincter function

The promise of stem cell therapy for the treatment of stress urinary incontinence is that transplanted stem cells may undergo self-renewal and potential multipotent differentiation, leading to urethral sphincter regeneration. Cell-based therapies are most often associated with the use of autologous multipotent stem cells, such as bone marrow cells. However, harvesting bone marrow stromal stem cells is difficult, painful, and may yield low numbers of stem cells. Alternatively, autologous adult stem cells, such as muscle-derived stem cells, can be obtained in large quantities and with minimal discomfort. Not all cells and cellular therapies are the same, however, and proper placement of cells into target structures may be critical to eventual treatment success. In particular, restoration and repair of the damaged urethral sphincter is crucial to maintain urinary continence because active urethral closure is largely mediated by pudendal nerves that innervate the striated muscles and rhabdosphincter of the middle urethra.     

Surface anatomy and surface landmarks for thoracic surgery

A thorough knowledge of thoracic anatomy is of fundamental importance to the thoracic surgeon. Surface anatomy is an often-neglected component of traditional topographic anatomic teaching, but a proper understanding of the relationship of surface features to deeper structures is invaluable in the clinical assessment of a patient and in the interpretation of radiologic imaging. Familiarity with thoracic surgical landmarks is a prerequisite for the successful placing of a thoracic incision. Knowledge of the intrathoracic anatomy and level of the diaphragm based on surface landmarks is useful for interventional procedures, such as tube thoracostomy. Knowledge of the chest wall musculature is essential in the use of muscle flaps for reconstruction.     

Interleukin-1beta-driven inflammation promotes the development and invasiveness of chemical carcinogen-induced tumors

The role of microenvironment interleukin 1 (IL-1) on 3-methylcholanthrene (3-MCA)-induced carcinogenesis was assessed in IL-1-deficient mice, i.e., IL-1beta(-/-), IL-1alpha(-/-), IL-1alpha/beta(-/-) (double knockout), and mice deficient in the naturally occurring inhibitor of IL-1, the IL-1 receptor antagonist (IL-1Ra). Tumors developed in all wild-type (WT) mice, whereas in IL-1beta-deficient mice, tumors developed slower and only in some of the mice. In IL-1Ra-deficient mice, tumor development was the most rapid. Tumor incidence was similar in WT and IL-1alpha-deficient mice. Histologic analyses revealed fibrotic structures forming a capsule surrounding droplets of the carcinogen in olive oil, resembling foreign body-like granulomas, which appeared 10 days after injection of 3-MCA and persisted until the development of local tumors. A sparse leukocyte infiltrate was found at the site of carcinogen injection in IL-1beta-deficient mice, whereas in IL-1Ra-deficient mice, a dense neutrophilic infiltrate was observed. Treatment of IL-1Ra-deficient mice with recombinant IL-1Ra but not with an inhibitor of tumor necrosis factor abrogated the early leukocytic infiltrate. The late leukocyte infiltrate (day 70), which was dominated by macrophages, was also apparent in WT and IL-1alpha-deficient mice, but was nearly absent in IL-1beta-deficient mice. Fibrosarcoma cell lines, established from 3-MCA-induced tumors from IL-1Ra-deficient mice, were more aggressive and metastatic than lines from WT mice; cell lines from IL-1-deficient mice were the least invasive. These observations show the crucial role of microenvironment-derived IL-1beta, rather than IL-1alpha, in chemical carcinogenesis and in determining the invasive potential of malignant cells.     

Molecular co-expression of the c-Met oncogene and hepatocyte growth factor in primary colon cancer predicts tumor stage and clinical outcome

INTRODUCTION/HYPOTHESIS: Over-expression of the c-Met receptor tyrosine kinase has been described in a variety of cancers and implicated in tumor progression. Unlike some solid tumors, current evidence indicates that c-Met activation in colon cancer is unrelated to gene mutation, is ligand dependent, and occurs via a paracrine fashion. We hypothesize that over-expression of the c-Met receptor and its ligand, hepatocyte growth factor (HGF) in the tumor microenvironment is associated with tumor progression and metastases. METHODS: Primary tumor c-Met and HGF mRNA expression was analyzed in 60 colon adenocarcinomas. Receptor and ligand expression was analyzed for correlation and association with clinicopathologic features and outcome. RESULTS: Compared to adjacent normal mucosa, 69% and 48% of tumors showed a greater than 2- and greater than 10-fold elevation in c-Met mRNA, respectively. Elevated HGF mRNA was noted in 47% of tumors with 19% having a greater than 10-fold increase. Tumor c-Met expression was correlated with HGF expression, and a cohort of 33 patients could be defined with both low c-Met and HGF expression. Compared with the 27 tumors with either high c-Met or HGF, the cohort with low c-Met and HGF expression had fewer nodal and distant metastases as well as improved overall survival (HR=2.3, p<0.05). CONCLUSION: Evaluation of the c-Met receptor in context of ligand, HGF, allows identification of a metastatic phenotype that correlates with advanced stage and poor survival. c-Met and HGF co-expression in the tumor microenvironment could be useful in the molecular staging of colon cancer and viable therapeutic targets.     

Churg‐Strauss syndrome with coexistence of eosinophilic vasculitis,granulomatous phlebitis and granulomatous dermatitis in bullous pemphigoid‐like blisters

The main histopathological features in the cutaneous lesions of Churg‐Strauss syndrome (CSS) are dermal leukocytoclastic vasculitis with a variable eosinophilic infiltrate and non‐vasculitic tissue eosinophilia with granuloma formation. This wide histopathological spectrum may account for the various skin manifestations of CSS. However, the unique histopathological combination of dermal eosinophilic vasculitis and subcutaneous granulomatous phlebitis accompanied by bulla formation has not been previously described. We report an unusual CSS case showing dermal necrotizing eosinophilic vasculitis and granulomatous phlebitis in purpuric lesions coupled with subepidermal blistering. The blisters showed dermal granulomatous dermatitis and eosinophilia without evidence of vasculitis. Dermal necrotizing eosinophilic vasculitis was characterized by fibrinoid alteration of the vessel wall, a prominent perivascular eosinophilic infiltrate, a few infiltrating histiocytes along the affected vessel wall, and the absence of neutrophilic infiltration. The underlying subcutaneous granulomatous phlebitis was characterized by an angiocentric histiocytic infiltrate surrounded by marked eosinophilic infiltrate. Deposition of cytotoxic proteins and radicals derived from eosinophils in the vessel walls and papillary dermis followed by a secondary granulomatous response may account for the unique clinical and histopathological features in this case. Ishibashi M, Kudo S, Yamamoto K, Shimai N, Chen K‐R. Churg‐Strauss syndrome with coexistence of eosinophilic vasculitis, granulomatous phlebitis and granulomatous dermatitis in bullous pemphigoid‐like blisters.