ALEXIS O‐Ring wound retractor vs conventional wound protection for the prevention of surgical site infections in colorectal resections1

Aim Surgical site infection (SSI) remains a common postoperative morbidity, particularly in colorectal resections, and poses a significant financial burden to the healthcare system. The omission of mechanical bowel preparation, as is performed in enhanced recovery after surgery programmes, appears to further increase the incidence. Various wound protection methods have been devised to reduce the incidence of SSIs. However, there are few randomized controlled trials assessing their efficacy. The aim of this study is to investigate whether ALEXIS wound retractors with reinforced O‐rings are superior to conventional wound protection methods in preventing SSIs in colorectal resections. Methodology Patients undergoing elective open colorectal resections via a standardized midline laparotomy were prospectively randomized to either ALEXIS or conventional wound protection in a double‐blinded manner. A sample size of 30 in each arm was determined to detect a reduction of SSI from 20% to 1% with a power of 80%. Secondary outcomes included postoperative pain. The operative wound was inspected daily by a specialist wound nurse during admission, and again 30 days postoperatively. Statistical analysis was performed using spss version 13 with P < 0.05 considered significant. Results Seventy‐two patients were recruited into the study but eight were excluded. There were no SSIs in the ALEXIS study arm (n = 34) but six superficial incisional SSIs (20%) were diagnosed in the control arm (P = 0.006). Postoperative pain score analysis did not demonstrate any difference between the two groups (P = 0.664). Conclusion The ALEXIS wound retractor is more effective in preventing SSI in elective colorectal resections compared with conventional methods.     

A systematic review of spleen and pancreas preservation in extended lymphadenectomy for gastric cancer

Background

The overall prognosis and survival of patients with advanced gastric cancer are generally poor. Extended lymphadenectomy is recommended for patients with advanced gastric cancer; however, splenectomy and distal pancreatectomy performed with an extended lymph node dissection may be associated with increased morbidity and mortality.

Method

Electronic literature searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from 1 January 1998 to 31 December 2009. Studies on gastric carcinoma investigating extended lymphadenectomy with splenectomy and/or pancreaticosplenectomy that reported data on surgical outcomes or survival were selected.

Results

Forty studies were included in this review. Decreased complication rates were demonstrated with spleen preservation in two prospective studies and three retrospective studies, and with pancreas preservation in five retrospective studies. No randomized controlled trial showed survival benefit or detriment for preservation of spleen or pancreas in extended lymphadenectomy. Improved survival was demonstrated with spleen preservation in two prospective and eight retrospective studies, and with pancreas preservation in one prospective and four retrospective studies.

Conclusions

Preservation of the spleen and pancreas during extended lymphadenectomy for gastric cancer decreases complications with no clear evidence of improvement or detriment to overall survival.

     

A meta-analysis of D1 versus D2 lymph node dissection

Background

Surgery is the only curative treatment for patients with gastric cancer. However, the extent of lymph node dissection is still debated. Therefore, with the publication of newer trial results, we conducted an updated meta-analysis of D1 versus D2 randomized controlled trials comparing outcomes.

Methods

Systematic searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 1985, to December 31, 2010. Meta-analyses were performed using RevMan v5 software. Both short- and long-term outcomes were analyzed. Subgroup analyses of T stage and spleen/pancreas resection versus preservation were performed.

Results

Outcomes of 5 randomized trials involving 1642 patients (845 D1, 797 D2) enrolled from 1982 to 2005 were included. Despite the addition of the more recent trials, overall hospital mortality and reoperation rates were still higher in D2 cases. Subgroup analysis of recent trials and spleen/pancreas preservation revealed no significant difference in hospital mortality between groups. Five-year overall survival was similar between D1 versus D2 trials. Sub-analysis by tumor depth and spleen/pancreas preservation detected trends for improved survival with D2 lymphadenectomy in T3/T4 patients and those with spleen/pancreas preservation.

Conclusion

Earlier trials show that D2 dissections have higher operative mortality, while recent trials have similar rates. A trend of improved survival exists among D2 patients who did not undergo resection of the spleen or pancreas, as well as for patients with T3/T4 cancers.

     

De novo 16p13.11 microdeletion identified by high-resolution array CGH in a fetus with increased nuchal translucency

Objective  We investigated the application of high-resolution microarray-based comparative genomic hybridisation (array CGH) on a fetus showing increased nuchal translucency (NT).
Design  Case study.
Setting  Tertiary referral obstetrics unit.
Sample  Pregnant woman attended the antenatal clinic.
Methods  Conventional karyotyping and genetic test was carried out for the alpha-globin gene. High-resolution array CGH using the high-density 244K Agilent microarray was performed on fetal blood sample by cordocentesis to investigate the possibility of any genomic imbalance.
Main outcome measures  Detection of chromosomal abnormality.
Results  Karyotyping analysis showed 46,XY. Molecular genetic diagnosis confirms the fetus has Hb-H constant spring disease but cannot explain the increased NT to 3.2 mm. Array CGH analysis discovered a 1.32-Mb microdeletion on chromosome 16p13.11. Deletion at 16p13.11 has been implicated to predispose to autism and/or mental retardation. Baby was delivered at 40 weeks of gestation, and follow up was carried out at 3 months of age without sign of mental retardation/developmental delay.
Conclusions  This case study demonstrated that array CGH can accurately calibrate the size and identify de novo interstitial chromosome imbalances. However, the presence of chromosome copy variants with unknown clinical significance currently limits its wider scale application in prenatal diagnosis and needs further investigations.     

A Visual study of surface potentials and Laplacians due to distributed neocortical sources: Computer simulations and evoked potentials

Summary A "picture book" of surface potentials, Laplacians, and magnetic fields due to distributed, neocortical sources is presented. The mathematically simulated data is based on 4200 current sources at the macrocolumn scale. Estimated scalp surface maps are based on the three-concentic spheres model of the head. Emphasis is placed on the effects of sampling with a limited number of electrodes, the choice of reference electrode, and the use of the spline Laplacian to improve spatial resolution. The spline Laplacian is applied to median and ulnar nerve somatosensory evoked potentials and to auditory evoked potentials including P300. Substantial improvement in spatial resolution over conventional methods is obtained. The implementation of practical high resolution EEG systems based on the spline Laplacian is considered.The authors greatfully acknowledge the technical assistance of Chris Fritton, Laurie Orth, and Chiraprakash Nayak. This research was supported by NIH grant RO1 NS24314.Invited paper, Submitted to Brain Topography, July, 1991     

A fatal case of bortezomib‐induced lung toxicity in a young adult heart transplant recipient

Bortezomib is approved for the treatment of multiple myeloma but increasingly used in heart transplant (HTx) recipients with antibody‐mediated rejection (AMR). Severe pulmonary toxicity is a rare complication in multiple myeloma patients treated with bortezomib, but has not been described in a solid organ transplant recipient. A 20‐year‐old man 7 years post‐HTx presented with acute rejection with hemodynamic compromise. Endomyocardial biopsy showed mixed rejection (ISHLT grade 2R‐3R acute cellular rejection (ACR) and pAMR 1 (I+) with diffuse C4d staining). Two new high MFI circulating MHC class‐II donor‐specific antibodies (DSA) were detected. Treatment included corticosteroids, antithymocyte globulin, plasmapheresis, IVIG, rituximab, and bortezomib (1.3 mg/m²). Due to rebound in DSA, a second course of bortezomib was started. Thrombocytopenia and peripheral neuropathy prompted a 50% dose reduction during the 2nd course. Shortly after the 3rd reduced dose, the patient developed hypoxemic respiratory failure. Bronchoscopy revealed pulmonary hemorrhage with negative infectious studies. Chest CT showed bilateral parenchymal disease with bronchiectasis and alveolar bleeding. Despite treatment with high‐dose steroids, severe ARDS ensued with multisystem organ failure. The patient expired 23 days after the final dose of bortezomib. Post‐mortem lung histology revealed diffuse alveolar damage, pulmonary fibrosis, and hemorrhage. Cardiac histology showed resolving/residual ACR 1R and pAMR 1 (I+). While rare, bortezomib‐induced lung toxicity (BILT) can occur in HTx recipients and can carry a high risk of mortality. Drug reaction and immediate drug withdrawal should be considered in patients who develop respiratory symptoms, though optimal management of BILT is unclear.     

Activation of human T lymphocytes by crosslinking of anti-CD3 monoclonal antibodies

The proliferation of human T lymphocytes induced by anti-CD3 monoclonal antibodies (mAb) is used as a model for antigen-induced activation via the T cell receptor-CD3 complex. Since both systems are accessory cell (AC)-dependent, an understanding of the role of AC in anti-CD3-induced proliferation may provide an understanding of physiological activation via the T cell receptor. Previous work has implicated receptor crosslinking as an important AC function. To determine its necessity in anti-CD3-induced lymphocyte proliferation, we prepared highly purified T lymphocytes and found that these cells did not respond to the anti-CD3 mAb UCHT1, either alone or with interleukin 1 (IL1), interleukin 2 (IL2), or tetradecanoyl phorbol acetate (TPA). However, the response, as measured by appearance of IL2 receptors and proliferation, was restored by crosslinking with immobilized goat anti-mouse antibodies (GAM) and did not require the addition of IL1, IL2, or TPA. Thus, crosslinking of CD3 receptors was a sufficient signal for proliferation of these cells. Cyclosporine A (CsA) inhibited the activation induced by immobilized UCHT1. Since macrophages are the principle targets of CsA-mediated suppression of mitogen-induced proliferation, but macrophages do not participate in the response to immobilized anti-CD3, this may indicate that CsA was inhibiting crosslinking or a signal generated by it.     

An inwardly-directed sodium-amino acid cotransporter influences steady-state cell volume in slices of rat renal papilla incubated in hyperosmotic media

The effect of a neutral amino acid, 2-aminoisobutyric acid (AIB) on steady state cell volume has been examined in rat renal papillary slices incubated in hyperosmotic media (2,000 mosmol/kg H₂O) containing high concentrations of NaCl and urea (thus imitating papillary interstitial fluid the intact kidney during antidiuresis). Volumes were significantly increased (P<0.001) when external AIB was raised from 0.1 to 10 mmol/l. Na⁺-dependent AIB uptake occurred, and there were net increases in cell contents of Na⁺ and Cl^–. Replacement of Na⁺ by Li⁺, but not by other cations did not influence the effect of AIB concentration on cell volume, but this was abolished when Cl^– was replaced by other anions. The effect of AIB was abolished by diphenylamine-2-carboxylate (10^–3 mmol/l), bumetanide (at 1 mmol/l but not 10^–2 mmol/l) and by N,N-dicyclohexylcarbodiimide (0.5 mmol/l), but not by amiloride (1 mmol/l) or 4-acetamido-4-iso-thiocyanato-stilbene-2,2-disulphonic acid (1 mmol/l), and was enhanced by the presence of Ba²⁺ or quinine (1 mmol/l). The findings are interpreted in terms of an inwardly-directed Na⁺-amino acid contransporter which determines steady-state volume, requires simultaneous entry of Cl^– through conductive pathways, and whose effects on cell volume are moderated by K⁺ efflux through volume-sensitive K⁺ channels.