Selective muscle botulinum toxin A component paralysis in complex ventral hernia repair.

INTRODUCTION: Repair of complex ventral hernia presents a significant challenge plagued by high morbidity and recurrence. Recent studies have demonstrated significant benefits achievable with preoperative Botulinum Toxin A (BTA) chemical component paralysis to the abdominal wall muscles, facilitating primary closure of complex ventral hernia defects. However, transversus abdominis is known to play an integral role in truncal stability, and its paralysis can result in unwanted physiological changes. This is the first study to report on selective administration of preoperative BTA to internal and external oblique muscles only, thus sparing transversus abdominis from paralysis. METHODS: This is a prospective observational study of 46 patients who underwent either selective two-layer or standard three-layer abdominal wall muscle BTA injection prior to elective laparoscopic ventral hernia repair. Serial abdominal CT imaging was performed to compare defect size and length of the lateral abdominal musculature. RESULTS: 46 patients received preoperative BTA injections (23 in each group). A comparison of gains achieved from chemical component paralysis demonstrated no statistically significant difference between the two groups. Fascial closure was achieved in all cases, with no post-operative sequelae of abdominal hypertension. There are no hernia recurrences to date. CONCLUSION: Preoperative selective muscle chemical component paralysis is an effective technique to counteract the chronic muscle retraction observed in large ventral hernias. Transversus abdominis plays a significant role in truncal and spinal stability, and sparing it from paralysis preserves an important component of abdominal wall physiology and does not detract from the ability to primarily close complex defects.

Biofilms and effective porosity of hernia mesh: are they silent assassins?

PURPOSE: The purpose of this paper is to communicate two new concepts with the potential to cause major morbidity in hernia repair, effective porosity and biofilm. These 2 concepts are interrelated and have the potential to result in mesh-related complications. Effective porosity is a term well described in the textile industry. It is best defined as the changes to pore morphology after implantation of mesh in situ. It is heavily dependent on mesh construct and repair technique and has the potential to impact hernia repair by reducing mesh tissue integration and promoting fibrosis. Bacterial biofilm is a well-described condition affecting prosthesis in breast and join replacement surgery with catastrophic consequences. There is a paucity of information on bacterial biofilm in mesh hernia repair. We speculate that bacterial biofilm has the potential to reduce the effective porosity of mesh, resulting in non-suppurative mesh-related complications as well as the potential for late suppurative infections. We describe the aetiology, pathogenesis, diagnosis, treatment and preventative measures to address bacterial biofilm in mesh hernia surgery. Hernia surgeons should be familiar with these two new concepts which have the potential to cause major morbidity in hernia repair and know how to address them. METHODS: Ovid Medline and PubMed were searched for communications on "effective porosity" and "bacterial biofilm". RESULTS: There is a paucity of information in the literature of these conditions and their impact on outcomes following mesh hernia repair. CONCLUSIONS: We discuss the two concepts of effective porosity and biofilm and propose potential measures to reduce mesh-related complications. This includes choosing mesh with superior mesh construct and technical nuances in implanting mesh to improve effective porosity. Furthermore, measures to reduce bacterial biofilm and its consequences are suggested.

Laparoscopic repair of complex ventral hernia facilitated by pre-operative chemical component relaxation using Botulinum Toxin A.

PURPOSE: The operative management of complex ventral hernia poses a formidable challenge, despite recent advances in surgical techniques. Recurrence rates after complex ventral hernia repair remain high, and increase with each failed attempt. This study examines the effect of pre-operative abdominal wall chemical component relaxation using Botulinum Toxin A (BTA) to induce temporary flaccid paralysis in order to facilitate laparoscopic repair of large complex ventral hernia. METHODS: This is a prospective evaluation of 27 patients from January 2013 to August 2015 who underwent ultrasound guided BTA injections to the lateral abdominal wall muscles prior to elective complex ventral hernia repair. Non-contrast serial CT imaging was obtained pre- and post-BTA injection to measure change in fascial defect size and abdominal wall muscle thickness and length. Fascial defects were closed and hernias repaired using laparoscopic or laparoscopic-assisted intra-peritoneal onlay mesh (IPOM) techniques. RESULTS: 27 patients received pre-operative BTA injections which were well tolerated with no complications. Comparison of pre-BTA and post-BTA CT imaging demonstrated a significant increase in mean length of the lateral abdominal wall from 15.7 cm pre-BTA to 19.9 cm post-BTA (p < 0.0001), with mean unstretched length gain of 4.2 cm/side (range 0-11.7 cm/side). All hernias were surgically reduced and repaired with mesh, with no early recurrences. CONCLUSION: Pre-operative administration of BTA is a safe and effective technique in the pre-operative preparation of patients undergoing elective complex ventral hernia repair. This technique lengthens and relaxes the laterally retracted abdominal muscles and enables laparoscopic closure of large complex ventral hernia.

Intensive care unit environmental surfaces are contaminated by multidrug-resistant bacteria in biofilms: combined results of conventional culture, pyrosequencing, scanning electron microscopy, and confocal laser microscopy.

BACKGROUND: Hospital-associated infections cause considerable morbidity and mortality, and are expensive to treat. Organisms causing these infections can be sourced from the inanimate environment around a patient. Could the difficulty in eradicating these organisms from the environment be because they reside in dry surface biofilms? AIM: The intensive care unit (ICU) of a tertiary referral hospital was decommissioned and the opportunity to destructively sample clinical surfaces was taken in order to investigate whether multidrug-resistant organisms (MDROs) had survived the decommissioning process and whether they were present in biofilms. METHODS: The ICU had two 'terminal cleans' with 500 ppm free chlorine solution; items from bedding, surrounds, and furnishings were then sampled with cutting implements. Sections were sonicated in tryptone soya broth and inoculated on to chromogenic plates to demonstrate MDROs, which were confirmed with the Vitek2 system. Genomic DNA was extracted directly from ICU samples, and subjected to polymerase chain reaction (PCR) for femA to detect Staphylococcus aureus and the microbiome by bacterial tag-encoded FLX amplicon pyrosequencing. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were performed on environmental samples. FINDINGS: Multidrug-resistant bacteria were cultured from 52% (23/44) of samples cultured. S. aureus PCR was positive in 50%. Biofilm was demonstrated in 93% (41/44) of samples by CLSM and/or SEM. Pyrosequencing demonstrated that the biofilms were polymicrobial and contained species that had multidrug-resistant strains. CONCLUSION: Dry surface biofilms containing MDROs are found on ICU surfaces despite terminal cleaning with chlorine solution. How these arise and how they might be removed requires further study.

Assessment of the selection process for myocutaneous flap repair and surgical complications in pelvic exenteration surgery.

BACKGROUND: This study aimed to explore and quantify the selection process to guide the decision on closure type (myocutaneous flap repair (MFR) or primary closure) for people undergoing pelvic exenteration. METHODS: This was a retrospective analysis of a prospectively maintained database with review of hospital records for verification and capture of missing data. Associations between four risk factors (previous radiotherapy, previous abdominoperineal resection, need for total exenteration, need for sacrectomy) were assessed individually and collectively as predictors of closure type and wound complications. RESULTS: A total of 203 pelvic exenteration procedures were reviewed (75 primary and 122 recurrent cancers). Thirty-nine patients (19·2 per cent) had MFR and 164 (80·8 per cent) primary closure. Patients who had MFR were significantly more likely to exhibit each risk factor, confirming the selective decision process. MFR had higher rates of complications across all four risk factors, individually and combined. In the primary closure group, there was a significant correlation between the number of risk factors and the proportion of patients with a complication (r = 0·25, P = 0·008). In contrast, no such relationship was found for the MFR group (r = 0·01, P = 0·973). Among patients who had any complication, the primary closure group had significantly lower rates of any wound dehiscence (15 of 64 versus 17 of 28; P < 0·001) and total infection (16 of 64 versus 14 of 28; P = 0·019) compared with the MFR group. CONCLUSION: Rates of wound and septic complications after pelvic exenteration were low in patients with fewer than two risk factors who had a primary closure. MFR had significantly higher complication rates, and should be reserved for patients with two or more risk factors or extensive skin involvement.

Pancreatic trauma in children.

BACKGROUND/PURPOSE: The aim of this study was to determine the etiology, associated injuries, and outcome of children with pancreatic injuries. METHODS: A retrospective review was conducted of children under 16 years with pancreatic trauma admitted to the Children's Hospital at Westmead (CHW) from January 1983 to September 2002. Deaths were reported to the New South Wales Paediatric Trauma Death Registry (State Registry) from January 1988 to September 2002. RESULTS: Sixty-five cases were identified: 46 patients were admitted to CHW, and 22 deaths were reported to the State Registry (including 3 deaths at CHW). The median age was 6 years (range, 1 to 14 years). Boys accounted for 60% (n = 40) of cases, decreasing to 50% (n = 11) of those that died. Motor vehicle injuries (MVI) were the most common mechanism, accounting for 40% of survivors and 77% of those who died. Children were restrained incorrectly in 48% of all cases and in 67% of those who died. Significantly more children who died had head, chest, and abdominal visceral injuries, compared with those who survived. Death occurred as a result of head injuries in 68%, with only 3 deaths directly attributed to pancreatico-duodenal injuries. CONCLUSIONS: Pancreatic injuries remain uncommon in children. The most frequent mechanism was MVI, with incorrect use of passenger restraints an important contributing factor. Whereas mortality was mainly caused by other injuries, 3 deaths were directly attributable to pancreato-duodenal trauma.

Single nucleotide primer extension (SNuPE) analysis of the G6PD gene in somatic cells and oocytes of a kangaroo (Macropus robustus).

cDNA sequence analysis of the X-linked glucose-6-phosphate dehydrogenase (G6PD) gene has shown a base difference between two subspecies of the kangaroo, Macropus robustus robustus (wallaroo) and M. r. erubescens (euro). A thymine residue in the wallaroo at position 358 in exon 5 has been replaced by a cytosine residue in the euro, which accounts for the previously reported electrophoretic difference between the two subspecies. This base difference allowed use of the Single Nucleotide Primer Extension (SNuPE) technique to study allele-specific expression of G6PD at the transcriptional level. We began by examining G6PD expression in somatic cells and observed complete paternal X inactivation in all somatic tissues of adult female heterozygotes, whereas we found partial paternal allele activity in cultured fibroblasts, thus confirming previous allozyme electrophoresis studies. In late dictyate oocytes from an adult heterozygote, the assay also detected expression of both the maternal and paternal alleles at the G6PD locus, with the maternal allele showing preferential expression. Thus reactivation of the inactive paternally derived X chromosome occurs during oogenesis in M. robustus, although the exact timing of reactivation remains to be determined.