Disinfection of contaminated metal implants with an Er:YAG laser.

Infections related to orthopedic procedures are considered particularly severe when implantation materials are used, because effective treatments for biofilm removal are lacking. In this study, the relatively new approach for infection control by using an erbium:yttrium-aluminum-garnet (Er:YAG) laser was tested. This laser vaporizes all water containing cells in a very effective, precise, and predictable manner and results in only minimal thermal damage. For preliminary testing, 42 steel plates and 42 pins were seeded with mixed cultures. First, the minimally necessary laser energy for biofilm removal was determined. Subsequently, the effectiveness of biofilm removal with the Er:YAG laser and the cleansing of the metal implants with octenidine-soaked gauze was compared. Then, we compared the effectiveness of biofilm removal on 207 steel pins from 41 patients directly after explantation. Sonication and scanning electron microscopy were used for analysis. Laser fluences exceeding 2.8 J/cm2 caused a complete extinction of all living cells by a single-laser impulse. Cleansing with octenidine-soaked gauze and irradiation with the Er:YAG laser are both thoroughly effective when applied to seeded pins. In contrast, when explanted pins with fully developed biofilms were analyzed, we found a significant advantage of the laser procedure. The Er:YAG laser offers a secure, complete, and nontoxic eradication of all kinds of pathogens from metal implants without damaging the implant and without the possible development of resistance. The precise noncontact removal of adjacent tissue is a decisive advantage over conventional disinfectants. Therefore, laser irradiation could become a valuable method in every debridement, antibiotics, and implant retention procedure.

Monitoring of plexiform neurofibroma in children and adolescents with neurofibromatosis type 1 by [18 F]FDG-PET imaging. Is it of value in asymptomatic patients?

PURPOSE: About 10% of patients with neurofibromatosis type 1 (NF-1) develop malignant peripheral nerve sheath tumours (MPNST) mostly arising in plexiform neurofibroma (PN); 15% of MPNST arise in children and adolescents. 2-[18 F]fluoro-2-deoxy-d-glucose ([18 F]FDG)-PET (where PET is positron emission tomography) is a sensitive method in differentiating PN and MPNST in symptomatic patients with NF-1. This study assesses the value of [18 F]FDG-PET imaging in detecting malignant transformation in symptomatic and asymptomatic children with PN. METHODS: Forty-one patients with NF-1 and extensive PN underwent prospective [18 F]FDG imaging from 2003 to 2014. Thirty-two of the patients were asymptomatic. PET data, together with histological results and clinical course were re-evaluated retrospectively. Maximum standardised uptake values (SUVmax) and lesion-to-liver ratio were assessed. RESULTS: A total of 104 examinations were performed. Mean age at first PET was 13.5 years (2.6-22.6). Eight patients had at least one malignant lesion; four of these patients were asymptomatic. Two of four symptomatic patients died, while all patients with asymptomatic malignant lesions are alive. All malignant tumours could be identified by PET imaging in both symptomatic and asymptomatic patients. All lesions judged as benign by [18 F]FDG imaging and clinical judgment were either histologically benign if removed or remained clinically silent during follow-up. SUVmax of malignant and benign lesions overlapped, but no malignant lesion showed FDG uptake ≤3.15. Asymptomatic malignant lesions were detected with a sensitivity of 100%, a negative predictive value of 100% and a specificity of 45.1%. CONCLUSION: Malignant transformation of PN also occurs in asymptomatic children and adolescents. Detection of MPNST at early stages could increase the possibility of oncologically curative resections.

First Experiences with Incisional Negative Pressure Wound Therapy in a High-Risk Poststernotomy Patient Population treated with Pectoralis Major Muscle Flap for Deep Sternal Wound Infection.

BACKGROUND: Radical debridement and wound closure with vascularized flaps has become a standard procedure in the treatment of deep sternal wound infections. Negative pressure incision management systems have been proven to diminish wound infections after sternotomy. In this study, the utility of Prevena Incision Management System (KCI Licensing Inc.) was evaluated in obese patients who received unilateral pectoralis major flap for the treatment of deep sternal wound infections. METHODS: The outcome and wound-related complication rates of 19 obese patients (mean body mass index, 33.7) treated for deep sternal wound infection with pectoralis major muscle flap in combination with Prevena between 2011 and 2016 were compared with 28 obese patients treated with conventional wound dressing only between 2000 and 2010. RESULTS: In patients additionally treated with Prevena, significantly fewer surgical revisions due to wound-related complications were necessary as compared with patients who received conventional wound dressing (5.3 vs. 32.1%, p = 0.034). A significantly shorter ICU length of stay (median 0 vs. 3.5 days, p < 0.001) and a trend toward shorter length of hospitalization (median 14 vs. 19.5 days after pectoralis major flap) could be observed. CONCLUSION: The application of Prevena significantly reduced revision surgery rates in obese patients treated with unilateral pectoralis major flap for deep sternal wound infections.

High-resolution ultrasound visualization of the subcutaneous nerves of the forearm: a feasibility study in anatomic specimens.

INTRODUCTION: The aim of this ultrasound-anatomical study was to evaluate the ability of high-resolution ultrasound (HRUS) to visualize and infiltrate small subcutaneous nerves of the forearm in anatomic specimens. METHODS: Seven nonembalmed human bodies (4 men, 3 women; mean age at death, 60 years) were included in the study. Two investigators scanned the anatomic specimens using 15-MHz and 18-MHz HRUS transducers. The lateral, medial, and posterior antebrachial cutaneous nerves were scanned and interventionally marked with ink using HRUS-guidance. Subsequently, dissections were performed to assess the anatomical correlation of HRUS findings. RESULTS: All 3 nerves were identified consistently using HRUS. The precision of the ink-markings was excellent, with good correlation with the small peripheral branches of all 3 nerves. CONCLUSIONS: HRUS can identify precisely the small subcutaneous nerves of the forearm and may aid in both diagnosis and therapy in cases of neuropathy.

Comparative study of CO2- and Er:YAG laser ablation of multiple cutaneous neurofibromas in von Recklinghausen's disease.

With a prevalence of 1 in 3,000 births, neurofibromatosis type 1 (NF1) is one of the most common genetic disorders and is characterized by an uninhibited expansion of neural tissue. Occasionally, severe deformities occur, but frequently considerable cosmetic disfigurement is caused by the development of hundreds of benign cutaneous neurofibromas. The objective of this study was to evaluate the erbium:yttrium-aluminium-garnet (Er:YAG) laser as a therapeutic option for the removal of multiple cutaneous neurofibromas. In this prospective, comparative, in vivo study, 15,580 neurofibromas (44 operations on 21 patients) were removed via electrosurgery, CO2- or Er:YAG laser ablation. In 12 adjacent test areas, we compared the zone of thermal necrosis, the postoperative pain, the time to reepithelialization, the duration of postoperative erythema and the cosmetic outcome of these surgical methods. When compared to electrosurgery and CO2 laser ablation, the Er:YAG laser ablation outperformed the other methods of tumor removal. Rapid healing by second intention as well as the minimal discomfort and scar formation following Er:YAG laser ablation were noted. After 36 months of follow-up, permanent dyspigmentation was rare and hypertrophic scarring was not observed. Er:YAG laser vaporization of multiple cutaneous neurofibromas is a simple and rapid procedure that results in significantly better cosmetic results than CO2 laser treatment or electrosurgery.

Common anatomical variation in patients with idiopathic meralgia paresthetica: a high resolution ultrasound case-control study.

BACKGROUND: Meralgia paresthetica (MP) is a mononeuropathy of the lateral femoral cutaneous nerve (LFCN) characterized by pain, numbness or paresthesia on the anterolateral aspect of the thigh. Though several contributing factors have been identified, the cause of its idiopathic form still remains unclear. Anatomic and clinical studies have demonstrated a variable course for the LFCN and have suggested a contribution to the pathogenesis of MP. OBJECTIVE: It was the aim of the present case-control study to assess the anatomical course and compression site of the LFCN using high resolution ultrasound (HRUS) in patients suffering from idiopathic MP, and compare the anatomical course in these patients to an asymptomatic control group. STUDY DESIGN: Case-control study. SETTING: Nerve imaging center at a large university hospital in Austria. METHODS: Twenty-eight patients with a diagnosis of MP were included in this study (20 men, 8 women; mean age 54 years). The diagnosis was established by clinical history, physical examination, and diagnostic anesthetic block. Fifteen age- and gender-matched healthy volunteers served as the control group. Standardized HRUS examinations were performed by one experienced radiologist from June 2004 through April 2012. Two experienced radiologists reviewed the patients' standardized HRUS examinations and performed examinations in the control group to measure the minimal distance between the LFCN and the anterior superior iliac spine (ASIS). OUTCOMES: The minimal distance between the ASIS and the LFCN was measured using HRUS. RESULTS: The LFCN could be seen in all patients and volunteers. In MP patients, the mean distance between the LFCN and the ASIS was 0.52 cm (SD 0.46 cm), compared to a mean distance of 1.79 cm (SD 1.48 cm) in the control group (P < 0.001). LIMITATIONS: Limited sample size, retrospective design. CONCLUSIONS: The results of this study demonstrate a significantly different course of the LFCN, closer to the ASIS in patients with idiopathic MP.

Burning HOT: revisiting guidelines associated with home oxygen therapy.

Burn injuries secondary to home oxygen therapy (HOT) have become increasingly common in recent years, yet several guidelines for HOT and chronic obstructive pulmonary disease (COPD) neglect to stress the dangers of open flames. This retrospective review of burn injury admissions secondary to HOT to our burn centre from 2007 to 2012 aimed to establish the extent of this problem and to discuss the current literature and a selection of national guidelines. Out of six patients (five female, one male) with a median age of 72 (range 58-79), four were related to smoking, and two due to lighting candles. The mean total body surface area (TBSA) affected was 17% (range 2-60%). Five patients sustained facial burns, two suffered from inhalation injury (33.3%), and five required surgery (83.3%). Mean total length of stay was 20 days (range 8 to 33), and one patient died. Although mentioned in the majority, some guidelines fail to address the issue of smoking in light of the associated risk for injury, which in turn might have future implications in litigation related to iatrogenic injuries. Improved HOT guidelines will empower physicians to discourage smoking, and fully consider the risks versus benefits of home oxygen before prescription. With a view on impeding a rising trend of burns secondary to HOT, we suggest revision to national guidelines, where appropriate.

Surgical treatment of complex regional pain syndrome type II with regional subcutaneous venous sympathectomy.

BACKGROUND: The effectiveness of a new surgical technique for the treatment of severe chronic pain stages was evaluated. For the last 140 years, the treatment of complex regional pain syndrome type II (CRPS II) has been an unsolved problem. Therapeutic approaches have included conventional pain medication, physical therapy, sympathetic blocks, transcutaneous or spinal cord stimulation, injections or infusion therapies, and sympathectomy. When used alone or in combination, these therapies often yield unfavorable results. The majority of physicians who treat patients with CRPS are convinced that a surgical treatment of the affected extremity only exacerbates the symptoms, especially its hallmark excruciating pain. METHODS: Sixteen patients with a CRPS type II of the upper or lower limb were included in the study after ineffective pain therapy for more than 6 months. The most proximal region of pain associated with CRPS was localized, and 2% lidocaine was injected into that area. Once the sympathetic, deep, burning pain had been blocked, the subcutaneous veins in the previously determined area were surgically removed. A visual analog scale, the Nottingham Health Profile, and physical examinations were used to evaluate the outcome of the operation. RESULTS: Twelve (75%) surgically treated patients showed significant improvement in limb function, the visual analog scale, and the Nottingham Health Profile. CONCLUSIONS: These data and recent findings in animal models conclude that CRPS type II is maintained by a coupling of newly sprouted sympathetic and sensible fibers. These fibers can be resected with a regional subcutaneous venous sympathectomy. LEVEL OF EVIDENCE: Therapeutic study, level III.

The temporalis: blood supply and innervation.

Numerous reports have described the use of the temporalis muscle as a pedicled flap in reconstructive surgery. A detailed knowledge of the supplying vessels and nerves is necessary for functionally successful muscle transposition. However, controversial anatomic descriptions exist. In this study, 60 human cadavers were investigated to identify the arteries and nerves supplying the temporalis. Forty-three cadavers were dissected after embalming with 10% phenol/formaldehyde. An additional 10 cadavers were examined after injecting latex/barium sulfate (ratio, 1:1) to show the parts of the temporalis supplied by each artery using radiography. The innervating motor branches of the trigeminal nerve were identified by the Karnovsky technique in seven fresh cadavers. In all specimens, three arteries supplying the temporalis were identified: the anterior deep temporal artery (anterior part, 30 percent muscle mass), the posterior deep temporal artery (central part, 51 percent muscle mass), and the medial temporal artery (occipital and in 25 percent upper part, 19 percent muscle mass). Motor branches of the trigeminal nerve innervated the temporalis: the deep temporal nerves of the mandibular nerve (98 percent, central part), branches of the buccal nerve (95 percent, anterior part), and branches of the masseteric nerve (69 percent, posterior part). A remarkable variation of innervating nerve branches, and in 12 percent peripheral anastomoses between the motor nerve branches, were observed. The various numbers of innervating nerve branches demonstrate the difficulty of creating innervated or selectively denervated pedicled muscle flaps for reinnervation. Nevertheless, at least two different pedicled flaps using the anterior or central part of the temporalis can be selectively used for reconstructive surgery.