Objective assessment of dermal fibrosis in cutaneous scarring, using optical coherence tomography, high-frequency ultrasound and immunohistomorphometry of human skin.

BACKGROUND: Noninvasive quantitative assessment of dermal fibrosis remains a challenge. Optical coherence tomography (OCT) and high-frequency ultrasound (HFUS) can accurately measure structural and physiological changes in skin. OBJECTIVES: To perform quantitative analysis of cutaneous fibrosis. METHODS: Sixty-two healthy volunteers underwent multiple sequential skin biopsies (day 0 and 1-8 weekly thereafter), with OCT and HFUS measurements at each time point supported with immunohistomorphometry analysis. RESULTS: HFUS and OCT provided quantitative measurements of skin thickness, which increased from uninjured skin (1·18 and 1·2 mm, respectively) to week 1 (1·28 mm, P = 0·01; 1·27 mm, P = 0·02), and compared favourably with haematoxylin and eosin. Spearman correlation showed good agreement between techniques (P < 0·001). HFUS intensity corresponded to dermal density, with reduction from uninjured skin (42%) to week 8 (29%) (P = 0·02). The OCT attenuation coefficient linked with collagen density and was reduced at week 8 (1·43 mm, P < 0·001). Herovici analysis showed that mature collagen levels were highest in uninjured skin (72%) compared with week 8 (42%, P = 0·04). Fibronectin was greatest at week 4 (0·72 AU) and reduced at week 8 (0·56 AU); and α-smooth muscle actin increased from uninjured skin (11·5%) to week 8 (67%, P = 0·003). CONCLUSIONS: Time-matched comparison images between haematoxylin and eosin, OCT and HFUS demonstrated that epidermal and dermal structures were better distinguished by OCT. HFUS enabled deeper visualization of the dermis including the subcutaneous tissue. Choice of device was dependent on the depth of scar type, parameters to be measured and morphological detail required in order to provide better objective quantitative indices of the quality and extent of dermal fibrosis.

Diagnosis of Aortic Graft Infection: A Case Definition by the Management of Aortic Graft Infection Collaboration (MAGIC).

OBJECTIVE/BACKGROUND: The management of aortic graft infection (AGI) is highly complex and in the absence of a universally accepted case definition and evidence-based guidelines, clinical approaches and outcomes vary widely. The objective was to define precise criteria for diagnosing AGI. METHODS: A process of expert review and consensus, involving formal collaboration between vascular surgeons, infection specialists, and radiologists from several English National Health Service hospital Trusts with large vascular services (Management of Aortic Graft Infection Collaboration [MAGIC]), produced the definition. RESULTS: Diagnostic criteria from three categories were classified as major or minor. It is proposed that AGI should be suspected if a single major criterion or two or more minor criteria from different categories are present. AGI is diagnosed if there is one major plus any criterion (major or minor) from another category. (i) Clinical/surgical major criteria comprise intraoperative identification of pus around a graft and situations where direct communication between the prosthesis and a nonsterile site exists, including fistulae, exposed grafts in open wounds, and deployment of an endovascular stent-graft into an infected field (e.g., mycotic aneurysm); minor criteria are localized AGI features or fever ≥38°C, where AGI is the most likely cause. (ii) Radiological major criteria comprise increasing perigraft gas volume on serial computed tomography (CT) imaging or perigraft gas or fluid (≥7 weeks and ≥3 months, respectively) postimplantation; minor criteria include other CT features or evidence from alternative imaging techniques. (iii) Laboratory major criteria comprise isolation of microorganisms from percutaneous aspirates of perigraft fluid, explanted grafts, and other intraoperative specimens; minor criteria are positive blood cultures or elevated inflammatory indices with no alternative source. CONCLUSION: This AGI definition potentially offers a practical and consistent diagnostic standard, essential for comparing clinical management strategies, trial design, and developing evidence-based guidelines. It requires validation that is planned in a multicenter, clinical service database supported by the Vascular Society of Great Britain & Ireland.

Pathophysiology and burden of infection in patients with diabetes mellitus and peripheral vascular disease: focus on skin and soft-tissue infections.

Diabetes mellitus affects 284 million adults worldwide and is increasing in prevalence. Accelerated atherosclerosis in patients with diabetes mellitus contributes an increased risk of developing cardiovascular diseases including peripheral vascular disease (PVD). Immune dysfunction, diabetic neuropathy and poor circulation in patients with diabetes mellitus, especially those with PVD, place these patients at high risk for many types of typical and atypical infections. Complicated skin and soft-tissue infections (cSSTIs) are of particular concern because skin breakdown in patients with advanced diabetes mellitus and PVD provides a portal of entry for bacteria. Patients with diabetes mellitus are more likely to be hospitalized with cSSTIs and to experience related complications than patients without diabetes mellitus. Patients with PVD requiring lower extremity bypass are also at high risk of surgical site and graft infections. Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent causative pathogen in cSSTIs, and may be a significant contributor to surgical site infections, especially in patients who are colonized with MRSA on hospital admission. Patients with cSSTIs and diabetes mellitus or PVD experience lower clinical success rates than patients without these comorbidities, and may also have a longer length of hospital stay and higher risk of adverse drug events. Clinicians should be vigilant in recognizing the potential for infection with multi-drug-resistant organisms, especially MRSA, in these populations and initiating therapy with appropriate antibiotics.

European perspective and update on the management of complicated skin and soft tissue infections due to methicillin-resistant Staphylococcus aureus after more than 10 years of experience with linezolid.

Complicated skin and soft tissue infections (cSSTIs) are a diverse group of infections, with a range of presentations and microbiological causes. Hospitalization is common for patients with a cSSTI, which is treated by drainage of the affected area and with antibiotics. Host factors such as co-morbidities, and microbial factors, in particular drug resistance, complicate the management of these infections. Methicillin-resistant Staphylococcus aureus (MRSA) is an important cSSTI pathogen in Europe, and its involvement can be associated with poor patient outcomes. European guidelines recommend vancomycin, teicoplanin, linezolid, daptomycin, tigecycline or ceftaroline for treatment of MRSA cSSTIs. Of primary importance when treating cSSTIs is the agent's clinical efficacy against the causative pathogens, as well as its bioavailability in the skin and associated structures. Linezolid is well-suited for the treatment of MRSA cSSTIs; it achieves high penetration into skin and soft tissues with 100% oral bioavailability, and therefore enables an intravenous to oral switch and outpatient treatment. When eligible patients are offered oral therapy the associated length of hospital stay and overall costs can be reduced. Linezolid has demonstrated clinical efficacy and favourable outcomes in patients for the treatment of MRSA cSSTIs including the treatment of lower extremity infections. Furthermore, efficacy has been documented in key defined populations, such as individuals with renal impairment and the obese. The safety profile of linezolid is well-documented, making this antibacterial a viable choice for the treatment of MRSA cSSTIs.

Optical coherence tomography: a reliable alternative to invasive histological assessment of acute wound healing in human skin?

BACKGROUND: Gold-standard assessment of acute wound healing has traditionally been through histological analysis of biopsied tissue. However, this process is invasive with recognized side-effects. Optical coherence tomography (OCT) is a noninvasive technique generating high-resolution real-time images of cutaneous architecture. OBJECTIVES: To compare OCT with histological assessment of in vivo acute wound healing and ascertain the level of agreement between modalities for measurement of defined cutaneous structures. METHODS: Punch biopsies (5 mm) were harvested from 50 healthy volunteers. Wounds healed by secondary intention until they were re-excised 7, 14, 21 or 28 days later depending on random group allocation. Wounds were assessed weekly for 6 weeks using OCT and compared with histological findings derived from time-matched biopsies. Dimensions of four cutaneous structures were measured using both modalities and the level of agreement was established by Bland-Altman analysis. The mean greyscale value (MGV) of the upper reticular dermis was derived from OCT images at all time points. RESULTS: Both techniques showed anatomical congruity in normal and wounded skin with correlating architectural changes associated with inflammatory, proliferative and remodelling wound healing phases. MGV was significantly increased 6 weeks after wounding (P = 0·001) and may represent a novel measure of wound fibrosis. Despite good association of histomorphometric values with low but consistent bias (range -4·181 to 0·431 µm), Bland-Altman plots demonstrated poor agreement between OCT and histology. CONCLUSIONS: Optical coherence tomography enabled accurate assessment of healing tissue comparable with histological analysis of biopsy specimens. This noninvasive tool is highly suited to wound assessment and may represent a diagnostic alternative to punch biopsies.

Oncovascular surgery.

BACKGROUND: Surgical resection remains the cornerstone for the curative treatment of oncological disease. When a tumour mass encases a critical arterial or venous structure, successful symptom relief and long-term oncological control may be achieved through careful preoperative planning within a multi-disciplinary team incorporating oncological and vascular specialists. To highlight the strategic issues pertaining to the vascular management of these patients, this review addresses the principles in planning oncovascular surgery, namely where cancer resection necessitates concurrent ligation or reconstruction of a major vascular structure. DESIGN: A multiple electronic health database search was performed, including Medline, Embase, and Scopus. RESULTS: The published outcomes for different malignancies suggest that survival is dependent upon complete clearance of the primary pathology and tumour biology rather than vascular-related complications. CONCLUSION: Major vessel involvement of a tumour mass should not necessarily be considered a barrier to en bloc resection and hence curative surgery. Radical surgical resection may offer the only chance for cure or palliation for these patients. Detailed preoperative planning within an extended multi-disciplinary team that includes vascular specialists is essential for these complex patients.

Use of an extracorporeal femoral-carotid shunt in the management of complex supra-aortic disease.

Management of symptomatic multifocal supra-aortic atherosclerotic disease presents a complex surgical challenge. We describe a novel approach where a temporary extra-corporeal femoro-carotid shunt was used to maintain cerebral perfusion during hybrid surgical and endovascular treatment for tandem supra-aortic lesions.

Tissue engineering of blood vessels.

BACKGROUND: Tissue engineering techniques have been employed successfully in the management of wounds, burns and cartilage repair. Current prosthetic alternatives to autologous vascular bypass grafts remain poor in terms of patency and infection risk. Growing biological blood vessels has been proposed as an alternative. METHODS: This review is based on a literature search using Medline, PubMed, ISIS and CAS of original articles and reviews, and unpublished material and abstracts. RESULTS AND CONCLUSIONS: Complete incorporation into host tissues and the maintenance of a viable and self-renewing endothelial layer are the fundamental goals to be achieved when developing a tissue-engineered blood vessel. Sourcing of cells and modulating their interaction with extracellular matrix and supporting scaffold have been the focus of intense research. Although the use of tissue-engineered blood vessels in humans is so far limited, advances in our knowledge of stem cell precursors and the development of new biomaterials should enable this technology to reach routine clinical practice within a decade.

Routine measurement of radioisotope left ventricular ejection fraction prior to vascular surgery: is it worthwhile?

OBJECTIVE: To determine whether estimation of left ventricular (LV) ejection fraction (EF) by means of multiple gated acquisition (MUGA) scanning could reliably stratify cardiac risk prior to elective major vascular surgery. METHODS: A review of the English-language literature. RESULTS AND CONCLUSIONS: Twenty-two studies enrolling a total of 3096 patients were identified from 1984 to date. Selection bias, blinding of the results, different cut-off limits, and several retrospective studies were some of the problems preventing a comprehensive analysis. The resting LVEF was not found to be a consistent predictor of perioperative ischaemic cardiac events. In the perioperative phase, poor LV function was, mainly, predictive of congestive heart failure, and, in the long-term, of cardiac outcome. The presence of myocardial wall motion abnormalities was also associated with both a higher chance of postoperative cardiac complications and a worse long-term cardiac outcome. Although measurements of LV function seem to play a key role in defining a patient's long-term prognosis, the value of routinely measuring LVEF preoperatively is limited and, therefore, MUGA scanning cannot be recommended as a general screening test. Despite this, it has been widely used for cardiac risk assessment in vascular surgery, and only recently its popularity has started declining. Other tests, such as stress-echocardiography and myocardial perfusion imaging, used selectively in moderate-risk patients can refine prediction of cardiac risk. In the future, gated stress myocardial perfusion scintigraphy, perhaps combined with ANP/BNP plasma level determination, may become a first choice test in preoperative cardiac risk assessment.

Outcome of transaxillary rib resection for thoracic outlet syndrome--a 10 year experience.

BACKGROUND: This study assessed the outcome of transaxillary first and/or cervical rib resection in a unit, which has a policy of combined assessment by a neurologist and vascular surgeon. METHODS: 61 patients underwent 83 transaxillary rib resections for thoracic outlet syndrome. A retrospective case note review of these patients was undertaken. All patients completed a telephone questionnaire regarding long-term outcome. RESULTS: Post-operative outpatient assessment at a median of 6 months recorded 91.5% improved, of whom 61.5% were symptom-free. 61% were available for the telephone questionnaire at a median follow-up of 4 yr. 74% reported an improvement, with complete resolution in 58%. Six described temporary improvement following surgery. CONCLUSION: Transaxillary rib resection is a safe and effective procedure, allowing almost two thirds of patients a return to normal activity. Combined assessment by vascular and neurological teams may help in patient selection for surgery, as well as the accurate long-term assessment of outcome.

A randomized study to evaluate the effect of a perioperative infusion of dopexamine on colonic mucosal ischemia after aortic surgery.

PURPOSE: Colonic ischemia after aortic surgery is associated with increased mortality and morbidity rates. This study was conducted as a single-center side arm to a multicenter, randomized, placebo-controlled study to evaluate the effect of dopexamine hydrochloride on its incidence. METHODS: Thirty patients, mean age 65.1 years (range, 46-84), undergoing elective infrarenal aortic surgery were entered. Preoperative hemodynamic and respiratory parameters were optimized. Patients were then randomly assigned to receive a perioperative infusion of dopexamine at 2 microg/kg per minute (n = 12) or 0.9% saline placebo (n = 18). All patients underwent colonoscopy and biopsy preoperatively and 1 week postoperatively. Specimens were assessed for evidence of mucosal ischemia, presence of mast cell tryptase, myeloperoxidase activity, and both the inducible and endothelial isoforms of nitric oxide synthase. RESULTS: There was no significant difference in perioperative fluid and blood requirements or hemodynamic and respiratory parameters between the two groups. However, there was significantly less evidence of mucosal ischemic changes in dopexamine-treated patients (n = 1) compared with placebo (n = 8) (P =.049). Furthermore, when preoperative biopsies were compared with those performed 1 week postoperatively, nine (50%) patients in the placebo group and two (16.7%) in the dopexamine group scored worse. Although there was no significant difference in inflammatory markers between the two groups, both mast cell tryptase and myeloperoxidase expression were increased in patients with histologic evidence of ischemia (P <.05). Furthermore, inducible nitric oxide synthase staining within the vascular (P =.001) and lamina propria (P <.05) components of the mucosa was also significantly greater. CONCLUSION: A perioperative dopexamine infusion affords significant histologic protection to colonic mucosa after aortic surgery.

A comparison of para-anastomotic compliance profiles after vascular anastomosis: nonpenetrating clips versus standard sutures.

PURPOSE: Anastomotic compliance is an important predictive factor for long-term patency of small diameter vascular reconstruction. In this experimental study we compare the compliance of continuous and interrupted sutured vascular anastomoses with those using nonpenetrating clips. METHODS: Both common carotid arteries in nine goats (average weight, 57 +/- 5.7 kg) were transected, and end-to-end anastomoses were constructed with nonpenetrating clips or polypropylene sutures. The latter were applied with both interrupted and continuous techniques. Intraluminal pressure was measured with a Millar Mikro-tip transducer, and vessel wall motion was determined with duplex ultrasound equipped with an echo-locked wall-tracking system. Diametrical compliance was determined. Environmental scanning electron microscopy was performed on explanted anastomoses. RESULTS: There was a reduction in anastomotic compliance and associated proximal and distal para-anastomotic hypercompliant zones with the use of all techniques. However, compliance loss was significantly less in those anastomoses with clips and interrupted sutures when compared with continuous suture (P <.001). Furthermore, the total compliance mismatch across anastomoses with continuous sutures was significantly greater than those with clips or interrupted sutures (P <.05). The mean time for constructing clipped anastomoses was 5.7 +/- 1.4 minutes, which was significantly less than either continuous (P <.0001) or interrupted sutures (P <.0001). Furthermore, environmental scanning electron microscopy demonstrated minimal intimal damage with good intimal apposition in the clip group. CONCLUSION: Anastomoses performed with nonpenetrating clips resulted in improved para-anastomotic compliance profiles and reduced intimal damage when compared with those with polypropylene sutures. These benefits may enhance long-term graft patency by reducing the risk of anastomotic intimal hyperplasia.

Management of acute nontraumatic upper limb ischemia.

A retrospective review of all patients presenting to a tertiary referral center with acute nontraumatic upper limb ischemia between January 1992 and June 1997 was undertaken to examine the role of intraarterial thrombolysis in the management of such cases. Twenty-one patients were identified in the radiology and vascular surgery departments' registers. Twenty (95%) underwent angiography, demonstrating subclavian artery occlusion in four, axillary in two, brachial in 13, and one at the digital level. Intraarterial thrombolysis was attempted in 12 patients. There were three technical failures, all requiring embolectomy. Six had complete lysis and resolution of their symptoms. One patient had partial lysis but experienced no further rest pain. Thrombolysis was unsuccessful in two cases with one subsequently requiring embolectomy and the other surgical bypass. Three patients had surgical intervention as their primary procedure with two favorable outcomes and one ending in above-elbow amputation. Five patients were treated conservatively with heparin, resulting in three partial and two full recoveries. One patient experienced complete resolution of symptoms with an intravenous prostacyclin infusion. Both electrocardiograms (ECG) and echocardiograms (ECHO) were of limited diagnostic aid, and long-term warfarin anticoagulation was prescribed to all patients. There was no recurrence of upper limb ischemia at a median follow up of 18 months. Intraarterial thrombolysis is an effective first line treatment for acute nontraumatic upper limb ischemia in selected cases.

Cardiovascular surgery in the elderly.

Throughout the developed world, the population is aging at an alarming rate. This has become an issue of great concern. The growing number of elderly people within the community has several health and economic implications. The prevalence of atherosclerosis increases with age and directly impacts on the workload of both cardiac and vascular surgeons. The decision to operate should not be based on age alone but reflect an assessment of the risk benefit ratio of individual cases. Increased life expectancy, safer anaesthesia and less invasive surgical techniques have led to more patients being considered for surgical intervention. However, this will inevitably result in an overwhelming burden on national health resources, a factor that may force some practitioners to deny treatment on the grounds of chronological and not biological age.

Histological study of colonic ischaemia after aortic surgery.

BACKGROUND: Colonic ischaemia is a well documented complication of abdominal aortic reconstruction. In this prospective study patients had routine preoperative and postoperative colonoscopy and biopsy, in order to determine the true incidence and implications. METHODS: Fifty-six patients undergoing elective infrarenal aortic surgery, 28 for aneurysm and 28 for occlusive disease, had colonoscopy and biopsy before and 1 week after operation. RESULTS: Colonic ischaemia was identified histologically in biopsies from 16 (30 per cent) of 53 patients. Almost half the patients had normal macroscopic appearances. Two factors exhibited a statistically significant association with the development of ischaemia: prolonged cross-clamp time (P < 0.05) and postoperative diarrhoea (P< 0.001). Co-morbidity was much higher in patients with colonic ischaemia (P< 0.005). Overall morbidity was significantly greater in the aneurysm group (P < 0.05). CONCLUSION: Colonic ischaemia is common after aortic reconstruction. When suspected, colonoscopy with biopsy is diagnostic.

Carpal tunnel decompression under local anaesthetic and tourniquet control.

A postal survey within the North West Region (UK) revealed that 66% of the consultant orthopaedic surgeons did not use local anaesthesia routinely for carpal tunnel decompression. This prospective study was set up to assess the effectiveness, safety and patient tolerance of performing this procedure using local anaesthesia and upper arm tourniquet control. Eight-six carpal tunnel decompressions were performed on 75 consecutive and unselected patients with confirmed carpal tunnel syndrome over a 6-month period. Completed questionnaires were obtained before discharge. None or only slight discomfort was experienced for all aspects of the operation in at least 94%. None of the patients reported severe and unbearable discomfort. At review, 3 months postoperatively, all patients with the exception of two reported complete resolution of preoperative symptoms. The use of local anaesthesia and a tourniquet is safe, effective and well-tolerated in carpal tunnel decompressions.