Long-term follow-up of bilateral gracilis reconstruction following extra-levator abdominoperineal excision.

INTRODUCTION: Colorectal operations such as an extra-levator abdominoperineal (elAPE) excision for locally advanced or recurrent cancer create a significant perineal tissue deficit. Options for perineal reconstruction include bilateral pedicled gracilis muscle flaps (BPGMF). Fashioning the gracili into a 'weave' creates a muscular sling that supports pelvic contents and is a novel technique. Our series reports the outcomes of the BPGMF in 50 patients undergoing surgery for pelvic cancer. METHOD: This is a retrospective, single-centre study of patients undergoing reconstruction of perineal defects using BPGMF. All surgeries took place between January 2008 and February 2021. The primary outcome measured was perineal wound healing. The secondary outcomes measured were complications of surgical sites and length of hospital stay (short term), flap integrity on follow-up imaging and functional outcomes (long term). RESULTS: Fifty patients underwent perineal reconstruction using BPGMF (26 males). The median age was 62 years. The 30-day mortality was 2% (n = 1). The average follow-up period was 2 years. Complete perineal wound healing was 86% (42/49) at outpatient follow-up. Complication rates for the donor site and reconstructed site were 14% and 22%, respectively. Complications included infection (2% donor site, 12% perineum), haematoma (4% donor site), dehiscence (2% donor site, 4% perineum) and seroma (3% donor site, 2% perineum). CONCLUSION: BPGMF offers a reliable and technically simple muscle flap to reconstruct large perineal defects. The muscle flap integrity appears maintained on follow-up imaging despite a lack of flap monitoring tools. This cohort had minimal functional impairment following BPGMF.

Single centre experience of bilateral gracilis flap perineal reconstruction following extra-levator abdominoperineal excision.

AIM: A variety of tissue flaps have been described for the closure of perineal wounds following abdominoperineal excision of the rectum (APE) or exenteration for locally advanced/recurrent rectal cancer and salvage surgery for anal cancer. The aim of this study was to demonstrate the utility of the bilateral pedicled gracilis muscle flaps (BPGMFs) as a reconstruction option in these patients. This is of particular benefit when using a laparoscopic approach for the abdominal component of the operation, avoiding disruption of the abdominal wall and risk of herniation with other reconstruction options, e.g. vertical rectus abdominis myocutaneous flaps. METHOD: This is a retrospective single centre case series of patients who underwent reconstruction of perineal defects using BPGMFs using a novel weave technique, from January 2008 to August 2017. RESULTS: There were 25 patients (16 female), with a median follow-up of 19 months (3-102). The indications for BPGMFs were cancer resection (21) and perineal hernia (4). The median length of stay was 14 days (6-60). All-cause mortality was 36% within the follow-up period. A healed perineal wound was achieved in 72% of patients within 30 days (84% of patients received neoadjuvant chemoradiotherapy). The overall donor site complication rate was 20% (including infection, dehiscence, numbness, haematoma and seroma) and 28% for the perineal site (including infection, dehiscence and prolapse). CONCLUSIONS: BPGMFs provide an important option for reconstruction of the perineum particularly with a minimally invasive approach or with two stomas.

Pyoderma gangrenosum: a report of a rare complication after knee arthroplasty requiring muscle flap cover supplemented by negative pressure therapy and hyperbaric oxygen.

Pyoderma gangrenosum (PG) is rare ulcerating skin condition easily confused with wound infection following surgery. We report a complicated case of PG following knee arthroplasty where delayed diagnosis and repeated debridements lead to significant tissue loss. Successful reconstruction was achieved with a muscle flap, but subsequent reactivation of PG and superadded infection placed both the reconstruction and patient's life at risk. Prolonged combined use of negative pressure therapy (NPT), immunosuppression and hyperbaric oxygen (HBO) was successfully used to reduce the wound size, enhance wound granulation, promote re-epithelialisation, and provide pain relief. There is little or no published literature on these treatment modalities for the management of PG, with only one reported case using both NPT and HBO for PG (not following knee arthroplasty). More studies are necessary to determine the role of both modalities in the management of pathergy in large and complex wounds and the rare nature of this complication following knee arthroplasty explains the lack of evidence-based guidance. In conclusion, we suggest a surgical algorithm. This is the first report of PG following knee arthroplasty with the use of both NPT and HBO in order to achieve soft tissue coverage.

Comparison of evoked arousability in breast and formula fed infants.

BACKGROUND: Currently, there is no consistent evidence that breast feeding reduces the risk for sudden infant death syndrome (SIDS). Arousal from sleep is believed to be an important survival mechanism that may be impaired in victims of SIDS. Previously it has been shown that arousability is impaired by the major risk factors for SIDS such as prone sleeping and maternal smoking. AIMS: To establish whether arousability was altered by method of feeding, and whether breast fed infants would have lower arousal thresholds. METHODS: Forty three healthy term infants were studied using daytime polysomnography on three occasions: 2-4 weeks post-term, 2-3 months post-term, and 5-6 months post-term. Multiple measurements of arousal threshold (cm H(2)O) in response to nasal air jet stimulation applied alternately to the nares were made in both active sleep (AS) and quiet sleep (QS) while infants slept supine. Arousal thresholds and sleep period lengths were compared between formula fed and breast fed infants at each age. RESULTS: Arousal thresholds were not different between breast fed and formula fed infants in QS. However, in AS breast fed infants were significantly more arousable than formula fed infants at 2-3 months of age. There was no difference between groups of infants when sleep period length was compared at any study. CONCLUSIONS: Breast fed infants are more easily aroused from AS at 2-3 months of age than formula fed infants. This age coincides with the peak incidence of SIDS.

No more frayed ends--a technique for trimming the uneven ends of ruptured flexor tendons prior to repair.

We describe a technique for the accurate and conservative debridement of the ends of divided flexor tendons. We have found this technique particularly useful for the secondary repair of tendons after re-rupture.

Effects of maternal tobacco smoking, sleeping position, and sleep state on arousal in healthy term infants.

OBJECTIVES: To investigate whether a history of maternal tobacco smoking affected the maturation of arousal responses and whether sleeping position and infant age alters these relations. DESIGN: Healthy term infants (13 born to mothers who did not smoke and 11 to mothers who smoked during pregnancy) were studied using daytime polysomnography on three occasions: (a) two to three weeks after birth, (b) two to three months after birth, and (c) five to six months after birth. Multiple measurements of arousal threshold in response to air jet stimulation were made in both active sleep (AS) and quiet sleep (QS) when infants slept both prone and supine. RESULTS: Maternal smoking significantly elevated arousal threshold in QS when infants slept supine at 2-3 months of age (p<0.05). Infants of smoking mothers also had fewer spontaneous arousals from QS at 2-3 months in both prone (p<0.05) and supine (p<0.001) sleeping positions. In infants of non-smoking mothers, arousal thresholds were elevated in the prone position in AS at 2-3 months (p<0.01) and QS at 2-3 weeks (p<0.05) and 2-3 months (p<0.001). CONCLUSIONS: Maternal tobacco smoking significantly impairs both stimulus induced and spontaneous arousal from QS when infants sleep in the supine position, at the age when the incidence of sudden infant death syndrome is highest.

Dermal cellular inflammation in burns. an insight into the function of dermal microvascular anatomy.

The damage caused by thermal trauma is augmented by the subsequent inflammatory response in a similar fashion to reperfusion injury. Animal studies have demonstrated a significant role for neutrophils in this delayed damage, but little is known about the numbers of neutrophils or other leucocytes that enter human skin following burns. We have longitudinally examined profiles of leucocyte migration into five cases of human partial thickness burns in relation to continued dermal microvascular destruction during the acute post-burn period. All burn wounds had a rapid influx of neutrophils that was followed by a delayed influx of macrophages. Compared to the controls, the two superficial burns also had rapid and sustained influx of CD4 and CD8 lymphocytes via patent post capillary venules in the dermal superficial vascular plexus, whilst in the three deeper burns, in which this superficial vascular plexus was occluded, the number of lymphocytes decreased. These results suggest that the patterns of leucocyte extravasation were dependent on the initial level of vascular occlusion, indicating that the dermal microvascular anatomy plays a pivotal role in determining the composition of the extravascular inflammatory cell infiltrates. The potential importance of this finding is highlighted by the differences in wound behaviour associated with the different leucocyte profiles.

The prone sleeping position impairs arousability in term infants.

OBJECTIVE: To investigate whether the prone sleeping position impaired arousal from sleep in healthy infants and whether this impairment was related to cardiorespiratory variables, temperature, or age. STUDY DESIGN: Healthy term infants (n = 24) were studied with daytime polysomnography on 3 occasions: 2 to 3 weeks after birth, 2 to 3 months after birth, and 5 to 6 months after birth. Multiple measurements of arousal threshold (cm H(2)O) in response to air-jet stimulation applied alternately to the nares were made in both active sleep and quiet sleep when infants slept both prone and supine. RESULTS: Arousal thresholds were significantly higher in both active sleep and quiet sleep when infants slept prone at 2 to 3 weeks and 2 to 3 months, but not at 5 to 6 months. These increases were independent of any sleep position-related change in either rectal or abdominal skin temperature, respiratory rate, oxygen saturation, or heart rate. CONCLUSIONS: The prone position significantly impairs arousal from both active sleep and quiet sleep in healthy term infants. This impairment in arousability occurred with no clinically significant changes in cardiorespiratory variables or body temperature. Decreased arousability from sleep in the prone position provides an important insight into its role as a risk factor for sudden infant death syndrome.

Burn depth and its histological measurement.

This paper describes a new technique for burn depth measurement, based on the histological assessment of dermal microvascular occlusion in burn biopsies. The technique was validated in a preliminary study of acute progressive microvascular damage in five adults with partial thickness burns. Burn depth was calculated at three time points post burn from the mean histological measurement of the most superficial patent and the deepest blocked vessels in five separate sections from each biopsy. The results were expressed as a percentage of the total dermal thickness and correlated well with the laser Doppler measurement of dermal blood flow and clinical estimation of burn depth. The reproducibility of the technique was tested by the repeated blind analysis of five randomly chosen biopsies on a separate occasion. Altman-Bland plot analysis demonstrated a median variation of 0.1% (95% confidence interval -1 to 2%). A second independent observer (MPHT), who carried out a blind analysis of the same randomly chosen biopsies, tested the precision of the technique. The median variation was 2% (95% confidence interval -5 to 8.5%).

Evaluation of Delorme's procedure as a treatment for full-thickness rectal prolapse.

BACKGROUND: Delorme's procedure is a well tolerated perineal operation for full-thickness rectal prolapse. However, prolapse recurrence is common and reported recurrence rates vary widely. This study attempted to standardize outcome assessment for recurrence following primary and subsequent Delorme's operations. Patient and operative factors were analysed to identify any that might improve patient selection. METHODS: Some 101 primary and 17 secondary Delorme's procedures were carried out on 113 consecutive patients presenting with rectal prolapse, who were followed for a minimum of 12 months, unless death or recurrent prolapse intervened. The rate of prolapse recurrence was calculated using the Kaplan-Meier method of analysis. Patient age, sex, grade of incontinence, presence of diverticular disease, length of mucosal resection and position in the operative series were analysed to identify factors affecting recurrence. RESULTS: The predicted recurrence-free period for 50 per cent of patients undergoing primary and secondary Delorme's procedures was 91 (95 per cent confidence interval 77-105) and 27 (15-39) months respectively. None of the patient or operative factors analysed was related to recurrent prolapse. CONCLUSION: Delorme's procedure is a simple operation with satisfactory functional results which can be considered in all patients of all ages. However, high recurrence rates for primary and repeat operations should be explained to patients when planning their surgical management.

DNA cancer vaccination strategies target SV40 large tumour antigen in a murine experimental metastasis model.

Two plasmids encoding SV40 Tag under the control of different promoters have been examined for their ability to induce complete protection against murine experimental metastasis induced with an SV40-transformed tumour cell line. BALB/c mice immunized with a plasmid encoding SV40 Tag under the control of the SV40 promoter (pSV3neo) exhibited no detectable levels of anti-SV40 Tag antibody and were only partially protected from tumour foci development in the lungs after Intravenous tumour challenge. In contrast, mice receiving a plasmid encoding SV40 Tag under the control of the CMV promoter (pCMV-Tag) demonstrated high levels of anti-SV40 Tag antibody. These mice were completely protected from lung tumour foci development after challenge. Since antibody responses were induced only by the immunization which provided complete protection from metastatic tumour challenge, these data support the notion that antibody may play an important role in protection against experimental pulmonary metastasis within this model. Our results demonstrate that DNA immunization may serve as a possible immunotherapeutic strategy against cancers expressing tumour-specific or tumour-associated antigens.

DNA vaccination strategies against infectious diseases.

DNA immunisation represents a novel approach to vaccine and immunotherapeutic development. Injection of plasmid DNA encoding a foreign gene of interest can result in the subsequent expression of the foreign gene products and the induction of an immune response within a host. This is relevant to prophylactic and therapeutic vaccination strategies when the foreign gene represents a protective epitope from a pathogen. The recent demonstration by a number of laboratories that these immune responses evoke protective immunity against some infectious diseases and cancers provides support for the use of this approach. In this article, we attempt to present an informative and unbiased representation of the field of DNA immunisation. The focus is on studies that impart information on the development of vaccination strategies against a number of human and animal pathogens. Investigations that describe the mechanism(s) of protective immunity induced by DNA immunisation highlight the advantages and disadvantages of this approach to developing vaccines within a given system. A variety of systems in which DNA vaccination has resulted in the induction of protective immunity, as well as the correlates associated with these protective immune responses, will be described. Particular attention will focus on systems involving parasitic diseases. Finally, the potential of DNA immunisation is discussed as it relates to veterinary medicine and its role as a possible vaccine strategy against animal coccidioses.

Comparison of simian virus 40 large T antigen recombinant protein and DNA immunization in the induction of protective immunity from experimental pulmonary metastasis.

In this report we examine the ability of a recombinant tumor antigen preparation to prevent the establishment of experimental pulmonary metastasis. Baculovirus-derived recombinant simian virus 40 (SV40) large tumor antigen (T-Ag) was injected into BALB/c mice followed by challenge with an intravenous injection of syngeneic SV40-transformed tumorigenic cells. The experimental murine pulmonary metastasis model allows for the accurate measurement of metastatic lessions in the lungs at various times after the challenge, using computer-assisted video image analysis. Following challenge, lung metastasis and survival data for the groups of mice were obtained. Animals immunized with recombinant SV40 T-Ag showed no detectable sign of lung metastasis and survived for more than 120 days after challenge. Antibodies specific for SV40 T-Ag were detected in the serum of immunized mice by enzyme-linked immunosorbent assay. Splenocytes obtained from mice immunized with recombinant SV40 T-Ag did not lyse syngeneic tumor cells, indicating that no cytotoxic T lymphocyte response was induced. Control mice developed extensive lung metastasis and succumbed to lethal tumor within 4 weeks after challenge. These data indicate that immunization with the recombinant SV40 T-Ag induces protective, T-Ag-specific immunity in an experimental pulmonary tumor metastasis model.

Fetal immunization of baboons induces a fetal-specific antibody response.

Neonates face a high risk of infection because of the immaturity of their immune systems. Although the transplacental transfer of maternal antibodies to the fetus may convey improved postnatal immunity, this transfer occurs late in gestation and may fail to prevent in utero infection. Both fetal immunization and in utero exposure to antigen can result in a state of immunologic tolerance in the neonate. Tolerance induction of fetal and premature infant lymphocytes has become a paradigm for neonatal responsiveness. However, fetal IgM responses have been demonstrated to maternal immunization with tetanus toxoid and to congenital infections such as rubella, toxoplasma, cytomegalovirus and human immunodeficiency virus. Moreover, 1-week-old infants can respond to standard pediatric vaccination, and neonates immunized with polysaccharide antigens do not develop immunologic tolerance. Here, direct immunization of the baboon fetus with recombinant hepatitis B surface antigen produced a specific fetal IgG antibody response. No specific maternal antibody response was detected, eliminating the possibility of vertical antibody transmission to the fetus. Some infants also responded to later vaccinations with hepatitis B surface antigen, indicating that no immunological tolerance was induced by prior fetal immunization. These results characterize the ability of the fetal immune system to respond to in utero vaccination. We demonstrate that active fetal immunization can serve as a safe and efficient vaccination strategy for the fetus and neonate.

Outcome following the rehabilitation of hand trauma patients. The importance of a subjective functional assessment.

Objective measures of hand function have been used to assess the outcome of rehabilitation following trauma. However, subjective assessments of function have been avoided by clinicians due to the difficulty in proving their validity and reliability. We have developed a subjective hand function scoring system (HFS), based on an activities of daily living assessment, which is used in planning and monitoring progress through rehabilitation. The HFS for 64 traumatic hand injuries were assessed on admission and discharge, and a significant improvement was found. There was a positive correlation between the HFS on admission and both the severity of injury, and the length of time off work. This scoring system is not validated, but this study illustrates the use of subjective functional scoring systems in the planning, delivery and evaluation of rehabilitation.

Quantitation of tumor foci in an experimental murine tumor model using computer-assisted video imaging.

A method is described in which both number and diameter of lung tumor foci obtained from an experimental murine tumor model of pulmonary metastasis are quantified using a digital imaging device. Lungs obtained from mice previously inoculated with tumorigenic cells are stained with India ink and Fekete's solution. Using appropriate exposure settings and top-lighting, a charged-coupled device digital camera is used to obtain the image of the organ. The image is then analyzed by the associated video imaging analysis software. Diameter of tumor foci on the image is expressed in image pixels and foci are quantitated. Density and size threshold parameters are set, thereby eliminating the variability resulting from the subjective nature of manual enumeration of tumor foci. The method is objective and reproducible and should be useful for studies where quantifying tumor foci diameter and number directly from the organ is required.

Development of an experimental murine pulmonary metastasis model incorporating a viral encoded tumor specific antigen.

A SV40 murine tumor model was developed and characterized involving intravenous inoculation of BALB/c mice with syngeneic SV40-transformed kidney fibroblasts (mKSA cells). Following intravenous inoculation with mKSA cells, viable tumor cells were recovered from primary organ cell culture of the brain, spleen, lungs, and kidneys of tumor bearing mice. The presence of mKSA tumor cells in these tissues was confirmed by morphological identification and by immunofluorescence directed to SV40 large tumor antigen (T-ag). Additionally, a computer assisted method was used to enumerate and quantitate the size of tumor foci. Tumor foci were observed in the lungs and were quantifiable based on both size and number. The number and size of foci observed in the lungs of tumor bearing mice was dependent on the dose of mKSA cells and time post-inoculation. Ultimately, the tumor burden in inoculated mice was found to be lethal. Quantification of tumor foci in the lung, survival data, and detection of metastasis to organs at sites distal to tumor cell inoculation, provides specific reference points for use in examining the mechanism(s) of the immune response to tumors expressing viral antigen and in evaluating immunologic based therapies within this new SV40 murine tumor model. The methods described herein can be applied for the development of new animal models of metastasis that express viral encoded tumor-specific antigens.