Aberrant DNA Methylation, Expression, and Occurrence of Transcript Variants of the ABC Transporter ABCA7 in Breast Cancer

The ABC transporter ABCA7 has been found to be aberrantly expressed in a variety of cancer types, including breast cancer. We searched for specific epigenetic and genetic alterations and alternative splicing variants of ABCA7 in breast cancer and investigated whether these alterations are associated with ABCA7 expression. By analyzing tumor tissues from breast cancer patients, we found CpGs at the exon 5-intron 5 boundary aberrantly methylated in a molecular subtype-specific manner. The detection of altered DNA methylation in tumor-adjacent tissues suggests epigenetic field cancerization. In breast cancer cell lines, DNA methylation levels of CpGs in promoter-exon 1, intron 1, and at the exon 5-intron 5 boundary were not correlated with ABCA7 mRNA levels. By qPCR involving intron-specific and intron-flanking primers, we identified intron-containing ABCA7 mRNA transcripts. The occurrence of intron-containing transcripts was neither molecular subtype-specific nor directly correlated with DNA methylation at the respective exon-intron boundaries. Treatment of breast cancer cell lines MCF-7, BT-474, SK-BR3, and MDA-MB-231 with doxorubicin or paclitaxel for 72 h resulted in altered ABCA7 intron levels. Shotgun proteomics revealed that an increase in intron-containing transcripts was associated with significant dysregulation of splicing factors linked to alternative splicing.

Discrimination between 34 of 36 Possible Combinations of Three C>T SNP Genotypes in the MGMT Promoter by High Resolution Melting Analysis Coupled with Pyrosequencing Using A Single Primer Set

Due to its cost-efficiency, high resolution melting (HRM) analysis plays an important role in genotyping of candidate single nucleotide polymorphisms (SNPs). Studies indicate that HRM analysis is not only suitable for genotyping individual SNPs, but also allows genotyping of multiple SNPs in one and the same amplicon, although with limited discrimination power. By targeting the three C>T SNPs rs527559815, rs547832288, and rs16906252, located in the promoter of the O6-methylguanine-DNA methyltransferase (MGMT) gene within a distance of 45 bp, we investigated whether the discrimination power can be increased by coupling HRM analysis with pyrosequencing (PSQ). After optimizing polymerase chain reaction (PCR) conditions, PCR products subjected to HRM analysis could directly be used for PSQ. By analyzing oligodeoxynucleotide controls, representing the 36 theoretically possible variant combinations for diploid human cells (8 triple-homozygous, 12 double-homozygous, 12 double-heterozygous and 4 triple-heterozygous combinations), 34 out of the 36 variant combinations could be genotyped unambiguously by combined analysis of HRM and PSQ data, compared to 22 variant combinations by HRM analysis and 16 variant combinations by PSQ. Our approach was successfully applied to genotype stable cell lines of different origin, primary human tumor cell lines from glioma patients, and breast tissue samples.

The serine proteases dipeptidyl-peptidase 4 and urokinase are key molecules in human and mouse scar formation

Despite recent advances in understanding skin scarring, mechanisms triggering hypertrophic scar formation are still poorly understood. In the present study, we investigate mature human hypertrophic scars and developing scars in mice at single cell resolution. Compared to normal skin, we find significant differences in gene expression in most cell types present in scar tissue. Fibroblasts show the most prominent alterations in gene expression, displaying a distinct fibrotic signature. By comparing genes upregulated in murine fibroblasts during scar development with genes highly expressed in mature human hypertrophic scars, we identify a group of serine proteases, tentatively involved in scar formation. Two of them, dipeptidyl-peptidase 4 (DPP4) and urokinase (PLAU), are further analyzed in functional assays, revealing a role in TGFβ1-mediated myofibroblast differentiation and over-production of components of the extracellular matrix in vitro. Topical treatment with inhibitors of DPP4 and PLAU during scar formation in vivo shows anti-fibrotic activity and improvement of scar quality, most prominently after application of the PLAU inhibitor BC-11. In this study, we delineate the genetic landscape of hypertrophic scars and present insights into mechanisms involved in hypertrophic scar formation. Our data suggest the use of serine protease inhibitors for the treatment of skin fibrosis.

Interactions of BRCA1-mutated Breast Cancer Cell Lines with Adipose-derived Stromal Cells (ADSCs)

Lipofilling may constitute a technique to assist reconstruction of breasts following prophylactic mastectomy for patients with mutated BRCA1 or BRCA2 genes. However, to date it is not clear whether adipose-derived stromal cells (ADSCs) increase the risk of tumor initiation and progression in this situation. Therefore, the interactions of BRCA1 mutated breast cancer cell lines with normal ADSCs were investigated in the present study. Characteristics of MDA-MB-436 (BRCA1 c.5277 + 1G > A) and HCC1937 (BRCA1 p.Gln1756.Profs*74) were compared to MDA-MB-231 and T47D BRCA1/2 wild-type breast cancer cell lines. ADSCs were cultivated from lipoaspirates of a panel of BRCA1/2- wildtype patients. Interactions of conditioned medium (CM) of these cells with the breast cancer lines were studied using proliferation and migration assays as well as adipokine expression western blot arrays. CM of ADSCs exhibit a dose-dependent stimulation of the proliferation of the breast cancer cell lines. However, of the ADSC preparations tested, only 1 out of 18 samples showed a significant higher stimulation of BRCA1-mutated MDA-MB-436 versus wildtype MDA-MB-231 cells, and all CM revealed lower stimulatory activity for BRCA1-mutated HCC1937 versus wildtype T47D cells. Additionally, migration of breast cancer cells in response to CM of ADSCs proved to be equivalent or slower for BRCA1/2 mutated versus nonmutated cancer cells and, with exception of angiopoietin-like 2, induced expression of adipokines showed no major difference. Effects of media conditioned by normal ADSCs showed largely comparable effects on BRCA1-mutated and wildtype breast cancer cell lines thus advocating lipofilling, preferentially employing allogeneic non-mutated ADSCs.

Tissue distribution of epirubicin after severe extravasation in humans

PURPOSE

As critical parameter after extravasation of cytotoxic vesicants, anthracyclines were determined in removed tissue from patients requiring surgical intervention due to tissue necrosis. We monitored their distribution within the affected lesion to establish a possible dose-toxicity relation.

METHODS

From six patients scheduled for surgery, removed tissue flaps were systematically analysed by HPLC (epirubicin: 5 subjects; doxorubicin: 1 subject).

RESULTS

After extravasation, tissue concentrations were highly variable with an individual anthracycline distribution pattern ranging from a few nanograms up to 17 µg per 100 mg tissue, which indicated a substantial difference in tissue sensitivity among patients. The resection borders coincided with the extension of the erythema and guided the surgical intervention after demarcation of the lesion, which occurred usually 2 or 3 weeks after extravasation. At that time, drug was hardly detected at the resection borders. Wound drains were negative for the extravasated drugs while showing a time profile of vascular growth factors and inflammatory cytokines, which was highly similar to routine surgery. In all six patients, surgical debridement with immediate wound closure led to healing within approximately 2 weeks, when therapy was resumed in all patients with reasonable time delay.

CONCLUSION

Surgical intervention after demarcation of the extravasation lesion allows for almost uninterrupted continuation of treatment independent of the amount of extravasated anthracycline. As even minor amounts of the vesicants may trigger tissue necrosis, preventive measures merit the highest priority.

Extraosseous osteoblastoma: A rare cause of breast mass in a prepubertal girl

Extraosseous osteoblastoma of the breast, a rare disease, was diagnosed in a prepubertal girl. After tumor excision, the patient recovered well and an optimal cosmetic result was achieved. Interdisciplinary discussions about the case are essential.

Treatment of partial thickness burns of the face with Acticoat7™ : A retrospective single center study

Background

The face is affected in more than 50% of patients with extensive burn trauma. Effective treatment is of importance to avoid hypertrophic scarring, functional impairment and social stigmatization.

Material and methods

All patients treated with Acticoat7™ due to superficial and deep partial thickness burns of the face between 2008 and 2017 at the intensive care unit (ICU) for burn trauma at the Department for Plastic and Reconstructive Surgery of the Medical University of Vienna were retrospectively analyzed. Patients were evaluated for the number of required dressing changes until complete re-epithelialization, bacterial colonization, potential complications and the need for primary and secondary surgery.

Results

A total of 100 patients were analyzed. It took a median dressing change rate of 1 (range 0–5) in the superficial partial thickness and 3 (range 1–11) in the deep partial thickness group. Conservative treatment of deep partial thickness wounds was possible in 79% and 17% of these patients required secondary scar revision. Although bacterial colonization of the wounds frequently occurred, wound infections were rarely observed.

Conclusion

Acticoat7™ is a valuable dressing for treating superficial and deep partial thickness burn wounds of the face in an intensive care unit setting. It enables extended time intervals between dressing changes without an increased risk for complications.

[Management of surgical therapy for advanced hidradenitis suppurativa with special consideration of perioperative antibiotic treatment - a questionnaire study]

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic, recurrent, inflammatory skin disease, which affects areas of the body that bear apocrine glands. In extensive cases, a combination of surgical and antibiotic treatment is often needed. Studies are available on the effects of clindamycin, also in combination with rifampicin, or tetracyclines. However, there are few precise recommendations for the perioperative application of antibiotic agents.

PATIENTS/MATERIAL AND METHODS

An anonymous survey was conducted to determine the current status quo of perioperative antibiotic treatment. Physicians and surgeons were surveyed who worked at a department for plastic surgery, general surgery or dermatology in the German-speaking area. The questionnaire itself was created with Limesurvey© and was sent out to qualified departments, with the help from federal ministries of health. The responses were statistically analysed with IBM^® SPSS^® version 23.

RESULTS

In most cases, the antibiotic treatment started before surgical intervention. Bacterial swabs were the most important factor in the selection of antibiotic agents. Most of theparticipants adjusted the treatment to the microbiological results, regardless of the chosen moment of application. Clindamycin was the most often used topical and systemic agent. The combination with rifampicin was most common. Adalimumab was the most commonly used antibody against tumor necrosis factor-alpha (TNF-α). In nearly half of the cases, antibodies were combined with antibiotics, and then the duration of treatment was usually longer. The extent of the disease was the most important factor for the necessity of surgical interventions. The wide excision of the whole affected area with subsequent healing by secondary intention was the surgical method of choice in all but one area.

CONCLUSION

This study has shown that there are significant differences in the treatment between disciplines and countries. On the one hand, the disease severity, on the other hand, individual experience and preferences affect the treatment. Depending on the discipline that determined the therapy, some treatments are provided more rarely or not at all. Revised and up-to-date guidelines embodying all relevant disciplines would be desirable for a standardised therapy.

Abstract P4-13-06: Comparing immediate techniques of oncoplastic surgery (iTOP) with conventional breast conservation (CBC), the prospective controlled non-randomized iTOP trial (NCT01396993)

Introduction: Immediate techniques of oncoplastic surgery (iTOP) may be performed during breast conservation called oncoplastic breast conservation (OPBC) or skin/nipple sparing mastectomy defined as immediate breast reconstruction (IBR). There are no prospective data comparing both oncoplastic groups with women undergoing conventional breast conservation (CBC).

Hypothesis iTOP are able to resect larger breast cancers with a similar quality of life comparing CBC

Methods: Women with unilateral breast cancer stage I-III were eligible. Upon written and signed informed consent all relevant data including the two quality of life scales breast image scale (BIS) and Breast Q, were recorded at baseline as well as 6 and 12 months after surgery. Women were separated into three groups according to their standard treatment plan:

• conventional breast conservation (CBC)

• breast conservation with level I or II oncoplastic surgery (OPBC)

• immediate breast reconstruction (IBR) with implants/autologous tissue.

Results (statistics will be presented at the meeting): 206 women entered the trial (116 CBC, 46 OPBC, 44 IBR), 117 had a 6 month follow up and 99 were followed for 12 months. There were more pT2 and pT3 cancers (pT2: 15% and 14% versus 10%; pT3 7%, 7% and 2%; p at SABCS), more nodal positive cases (39%, 23% versus 12% p at SABCS) and more multifocal and multicentric cases (39%, 38% versus 20% p at SABCS) in the OPBC and IBR group compared with the CBC group. In 63% of cases the planned resection volume in OPBC was above 25% compared with 19% of cases in the CBC group. All groups had similar R1 resection rate (11%, 11% versus 9% p at SABCS) and no difference of the tumor distance to the resection margin. All groups were well balanced regarding neoadjuvant and adjuvant treatment. Only women with an IBR had an increased time to adjuvant radiotherapy compared with the other two groups (93 days versus 191 days median p at SABCS). Morbidity in OPBC was twice as high compared with IBR and CBC because of skin/wound necrosis and infections (total morbidity: 28% versus 16% and 12% p at SABCS). Quality of life using BIS, BREAST Q and VAS pain score did not differ between the three groups.

Conclusion: Oncoplastic surgery resects larger tumors with similar quality of life in women with breast cancer stage I-III but with a higher morbidity rate. Oncologic recurrence data will be presented after a follow up of 5 years.

CBCOPBCIBRn%n%n%1165746224421cT size1-2cm8271183916362-3cm201716358183-5cm109715818>5cm225111125FOCALITYunifocal938028612761multifocal1715817511multicentric6510221227PLANNED RESECTION VOLUME<25%9481173725>25%221929634295SEROMAyes10971512no1119644964398BLEEDINGyes223712no1119644964398NECROSISyes004949no11610042914091INFECTIONyes2261325no1149840874295VAS 6monthsmedian221percentile0-30-30-3.5VAS 12monthsmedian000.5percentile0-40-20.2BISat 12 months median (percentile)32-4.532-343-5.5

Citation Format: Michael Bolliger, Andreas Gleiss, Michael Schütz, Pia Lanmüller, Tanja Keusch, Bernhard Heilig, Werner Haslik, Daniela Dörfler, Lena Theresa Maghörndl, Florian Fitzal. Comparing immediate techniques of oncoplastic surgery (iTOP) with conventional breast conservation (CBC), the prospective controlled non-randomized iTOP trial (NCT01396993) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-13-06.

Deciphering the functional heterogeneity of skin fibroblasts using single-cell RNA sequencing

Though skin fibroblasts (FB) are the main cell population within the dermis, the different skin FB subsets are not well characterized and the traditional classification into reticular and papillary FBs has little functional relevance. To fill the gap of knowledge on FB diversity in human skin, we performed single-cell RNA sequencing. Investigation of marker genes for the different skin cell subtypes revealed a heterogeneous picture of FBs. When mapping reticular and papillary FB markers, we could not detect cluster specificity, suggesting that these two populations show a higher transcriptional heterogeneity than expected. This finding was further confirmed by in situ hybridization, showing that DPP4 was expressed in both dermal layers. Our analysis identified six FB clusters with distinct transcriptional signatures. Importantly, we could demonstrate that in human skin DPP4⁺ FBs are the main producers of factors involved in extracellular matrix (ECM) assembly. In conclusion, we provide evidence that hitherto considered FB markers are not ideal to characterize skin FB subpopulations in single-cell sequencing analyses. The identification of DPP4⁺ FBs as the main ECM-producing cells in human skin will foster the development of anti-fibrotic treatments for the skin and other organs.

Air-fluidized therapy in the treatment of severe burns: A retrospective study from a burn intensive care unit in Austria

INTRODUCTION

Air-fluidized therapy (AFT) has long been used in the treatment of severe burns. In patients with extensive burns involving the posterior trunk, we aim to keep affected posterior areas dry and to postpone their treatment, initially applying available split-thickness skin grafts in functionally more important regions. We retrospectively assessed the impact of AFT on the survival of patients treated in the burn intensive care unit (ICU) of the Medical University of Vienna, Austria, between 2003 and 2016.

METHODS

This retrospective single-center study included patients aged ≥18 years with burned total body surface area (TBSA) ≥20% and IIb-III° thermal injuries on the posterior trunk who received AFT. Survival rates were compared with those predicted by the abbreviated burn severity index (ABSI). Demographic, clinical, and surgical data were analyzed.

RESULTS

Seventy-five of 110 patients with posterior trunk burns received AFT. Their survival rate exceeded that predicted by the ABSI score (mean ABSI, 10.0 ± 2.0; 73.3% (95% CI: 62-83%) survival rate vs. 20-40% predicted; p <  0.0001); no such difference was observed in the non-AFT group (mean, 8.8 ± 1.9; 65.7% (95% CI: 48-81%) survival rate vs. 50-70% predicted). Patients receiving AFT had significantly greater TBSA (median, 50% (35-60) vs. 30% (25-45) and longer ICU stays (median, 63 (36-92) vs. 18 (9-52) days; both p <  0.0001). Fifty-one (68.0%) patients in the AFT group and 26 (74.3%) patients in the non-AFT group underwent posterior trunk surgery (p =  0.66) a median of 16 (10-26) and 5 (2.5-9.5) days, respectively, after admission (p <  0.0001).

CONCLUSIONS

Patients receiving AFT had significantly better survival than predicted by ABSI score in contrast to patients not receiving AFT although burn injuries in this group were more severe (greater TBSA, higher ABSI). As intensive care was similar in these groups aside from AFT, the better survival could be attributed to this additional therapy.

Optimization of breast reconstruction results using TMG flap in 30 cases: Evaluation of several refinements addressing flap design, shaping techniques, and reduction of donor site morbidity

BACKGROUND

The transverse myocutaneous gracilis (TMG) flap is a widely used alternative to abdominal flaps in autologous breast reconstruction. However, secondary procedures for aesthetic refinement are frequently necessary. Herein, we present our experience with an optimized approach in TMG breast reconstruction to enhance aesthetic outcome and to reduce the need for secondary refinements.

METHODS

We retrospectively analyzed 37 immediate or delayed reconstructions with TMG flaps in 34 women, performed between 2009 and 2015. Four patients (5 flaps) constituted the conventional group (non-optimized approach). Thirty patients (32 flaps; modified group) underwent an optimized procedure consisting of modified flap harvesting and shaping techniques and methods utilized to reduce denting after rib resection and to diminish donor site morbidity.

RESULTS

Statistically significant fewer secondary procedures (0.6 ± 0.9 versus 4.8 ± 2.2; P < .001) and fewer trips to the OR (0.4 ± 0.7 versus 2.3 ± 1.0 times; P = .001) for aesthetic refinement were needed in the modified group as compared to the conventional group. In the modified group, 4 patients (13.3%) required refinement of the reconstructed breast, 7 patients (23.3%) underwent mastopexy/mammoplasty or lipofilling of the contralateral breast, and 4 patients (13.3%) required refinement of the contralateral thigh. Total flap loss did not occur in any patient. Revision surgery was needed once.

CONCLUSIONS

Compared to the conventional group, enhanced aesthetic results with consecutive reduction of secondary refinements could be achieved when using our modified flap harvesting and shaping techniques, as well as our methods for reducing contour deformities after rib resection and for overcoming donor site morbidities.

Extravasation emergencies: state-of-the-art management and progress in clinical research

In cancer treatment, extravasation is defined as an inadvertent instillation or leakage of cytotoxic drugs into the perivascular space during infusion. As a dreaded complication of chemotherapy, extravasation has gained increasing attention in recent years. Classified according to their subcutaneous toxicity, three types of cytotoxins have been established: vesicants, irritants and nonvesicant drugs. Vesicant cytotoxic drugs may induce tissue damage, ulceration and tissue necrosis. Although we have established measures to manage extravasation emergencies, prevention is of paramount importance. This may be achieved within hospitals through regular training and education, which is best provided by a specialised and experienced task force including all disciplines involved in cancer therapy. Moreover, clinical and translational studies contribute to a better management of chemotherapy-induced extravasation as shown by our group in recent years. We were able to demonstrate that the evaluation of blood flow by indocyanine green angiography in the extravasation area predicts the extent of damage and the need of future surgical intervention. When a Port-a-Cath® extravasation is detected early, a subcutaneous wash-out procedure was found to be beneficial, corroborated by the analytical evaluation of the removed cytotoxic compound epirubicin. In another study, the tissue distribution of platinum was quantified at the anatomic level in cryosections of various tissues. This novel knowledge complements and supports our current efforts to handle extravasations better. On the other hand, a number of new drugs (chemotherapy, monoclonal antibodies, checkpoint inhibitors etc.) with many open issues to reliably classify their tissue toxicity still require our attention.

Carpal Tunnel Syndrome: A Question of Hand and Wrist Configurations?

This study investigated whether there is an association between hand and wrist configurations and the occurrence of carpal tunnel syndrome. The external hand and wrist dimensions of 50 subjects with carpal tunnel syndrome and 50 healthy volunteers were measured and compared. In addition carpal tunnel depth and width were determined with ultrasound. Our results showed that the hand length was significantly higher in the control group (hand length, 19.0; SD, 1.0 cm: patients’ hand length, 18.2; SD, 1.1 cm) and the palm width was significantly greater in the patients’ group (palm width, 9.1; SD, 0.7 cm: controls palm width, 8.6; SD, 0.6 cm). Carpal tunnel syndrome patients had a squarer wrist (wrist ratio, 0.72; SD, 0.1) and carpal tunnel (carpal tunnel ratio, 0.48; SD, 0.1) than the controls (wrist ratio, 0.68; SD, 0.1; carpal tunnel ratio, 0.42; SD, 0.1). These findings indicate that the anatomy of the hand, wrist and carpal tunnel may predispose to carpal tunnel syndrome.

Viability of five different pre- and intraoperative imaging methods for autologous breast reconstruction

Background

Autologous breast reconstruction is an integral part in the treatment of breast cancer. While computed tomography angiography (CTA) is an established preoperative diagnostic tool for microsurgeons, no study has so far evaluated and compared five different imaging methods and their value for the reconstructive team. In order to determine the feasibility of each of the tools for routine or specialized diagnostic application, the methods' efficiency and informative value were analyzed.

Methods

We retrospectively analyzed imaging data of 41 patients used for perforator location and assessment for regional perfusion and vessel patency in patients undergoing autologous breast reconstruction with deep inferior epigastric perforator flap (DIEP), transverse rectus abdominis muscle flap (TRAM), or transverse myocutaneous gracilis flap (TMG). Five different imaging techniques were used: hand held Doppler (HHD), CT angiography (CTA), macroscopic indocyanine green (ICG) video angiography, microscope-integrated ICG video angiography, and laser Doppler imaging (LDI).

Results

CTA proved to be the best tool for preoperative determination of the highly variable anatomy of the abdominal region, whereas HHD showed the same information on perforator localization with some false-positive results. Intraoperative HHD was an excellent tool for dissection and vessel patency judgment. Microscope-integrated ICG was an excellent tool to document the patency of microanastomoses. In our series, macroscopic perfusion measurement with ICG or LDI was only justified in special situations, where information on perfusion of abdominal or mastectomy flaps was required. LDI did not add any additional information.

Conclusion

Preoperative assessment should be performed by CTA with verification of the perforator location by HHD. Intraoperative HHD and microscope-integrated ICG contribute most toward the evaluation of vessel patency. ICG and LDI should only be used for special indications.

Extravasation of Pt-based chemotherapeutics – bioimaging of their distribution in resectates using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

Spatially resolved quantification of platinum distribution in patients that exhibited extravasation was feasible up to 4 weeks upon drug application.

Indocyanine green video angiography predicts outcome of extravasation injuries

BACKGROUND

Extravasation of cytotoxic drugs is a serious complication of systemic cancer treatment. Still, a reliable method for early assessment of tissue damage and outcome prediction is missing. Here, we demonstrate that the evaluation of blood flow by indocyanine green (ICG) angiography in the extravasation area predicts for the need of surgical intervention.

METHODS

Twenty-nine patients were evaluated by ICG angiography after extravasation of vesicant or highly irritant cytotoxic drugs administered by peripheral i.v. infusion. Tissue perfusion as assessed by this standardized method was correlated with clinical outcome.

RESULTS

The perfusion index at the site of extravasation differed significantly between patients with reversible tissue damage and thus healing under conservative management (N = 22) versus those who needed surgical intervention due to the development of necrosis (N = 7; P = 0.0001). Furthermore, in patients benefiting from conservative management, the perfusion index was significantly higher in the central extravasation area denoting hyperemia, when compared with the peripheral area (P = 0.0001).

CONCLUSIONS

In this patient cohort, ICG angiography as indicator of local perfusion within the extravasation area was of prognostic value for tissue damage. ICG angiography could thus be used for the early identification of patients at risk for irreversible tissue damage after extravasation of cytotoxic drugs.

Extraordinary Lymph Drainage in Cutaneous Malignant Melanoma and the Value of Hybrid Imaging: A Case Report

In melanoma patients, preoperative lymphoscintigraphy has become a gold standard. The role of single-photon emission computed tomography (SPECT) or its combination with computed tomography (SPECT-CT) as part of the standard sentinel scintigraphy protocol has yet to be determined. A 46-year-old female patient with melanoma of the trunk received preoperative lymphoscintigraphy and subsequent surgical excision. Planar imaging displayed two hot spots in the region of the primary lesion. No other lymphatic flow pathways could be appreciated. Two focal hot spots, one dorsal to the primary lesion near the left latissimus dorsi muscle and one just lateral to the primary lesion in the subcutaneous tissue, were appreciated with SPECT-CT imaging. The primary melanoma lesion, as well as the two additional lesions, which were detected by SPECT-CT, were excised and sent for histopathological examination. While the primary lesion was a superficial spreading melanoma, the lesions appreciated in SPECT-CT revealed four sentinel lymph nodes, each of which was negative for tumor cells. Melanomas, especially of the trunk, can demonstrate multiple lymphatic drain basins in a large percentage of patients. Given that without the detailed anatomical information provided by SPECT-CT it would be very difficult to locate the diverse lymphatic drain basins and their lymph nodes, we would suggest routinely implementing SPECT-CT in the standard planar sentinel imaging protocol.

[Squamous cell carcinoma in Dupuytren's disease--a case report]

Squamous cell carcinoma in the palm is an extremely rare entity. In the following case report we describe the occurrence of a squamous cell carcinoma in the presence of Dupuytren's disease. A 49-year-old man was operated on the right hand for ulcerating Dupuytren's disease. A squamous cell carcinoma was diagnosed by performing obtaining a fast section intraoperatively. The patient had an invasive, highly differentiated keratinizing squamous cell carcinoma. The lesion was resected together with the Dupuytren lesion and the defect covered with a full-thickness graft. Postoperatively the patient was irradiated. He is free of recurrence for three years now. To our knowledge, this is the first published report of a squamous cell carcinoma in the presence of Dupuytren's disease.

First experiences with the collagen-elastin matrix Matriderm as a dermal substitute in severe burn injuries of the hand

Restoring function after hand burns plays a major role in the restitution of a quality of life. Thereby the reconstructed pliability of the grafted areas is of utmost importance for good hand function. The collagen elastin matrix Matriderm was evaluated as a dermal substitute for the treatment of severe hand burns. In a series of 10 patients, mean age 43 years, TBSA 22.8%, an early debridement and immediate grafting with the matrix and unmeshed skin graft was carried out in a one-stage procedure. In the early postoperative follow up an overall take rate of 97% was observed. In contrast to conventional skin grafts, the color of the skin grafts over the matrix appeared pale in the first few days, but after 2 weeks no difference was observed. After three months, pliability of the grafted area was excellent, (mean VSS 3.2+/-1.2). Full range of motion was achieved in all hands, no blisters and no unstable or hypertrophic scars occurred. Matriderm has proved to be a dermal substitute suitable for the treatment of hand burns. We therefore consider Matriderm as a promising dermal substitute for the treatment of severe hand burns.

Microneurovascular anatomy of the peroneus brevis muscle in the NZW-rabbit: a new model for free functional muscle transplantation

This study introduces the peroneus brevis muscle of the NZW-rabbit as a new model for free functional muscle transplantation. The muscle originates from the lateral aspect of the knee joint and inserts on the 5th metatarsal with a circumscript tendon. It can be harvested with a 7 cm long motor nerve branch. In a series of 22 animals divided in two groups with a body weight of 3.19 +/- 0.30 kg and 4.81 +/- 0.38 kg respectively, vessel diameter of the supplying artery was found to be 0.3-0.35 mm in group one and 0.40-0.45 mm in group two, the two concomitant veins were 1.1-1.4 mm in diameter in the first group and 1.2-1.6 mm in the second group. Histomorphometric analysis stained with NADH showed 3.67 +/- 3.21% type I fibers, 25.41 +/- 7.87% type IIa fibers, and 70.93 +/- 9.12% type IIb/d fibers.

Free functional muscle transplantation for facial reanimation: experimental comparison between the one- and two-stage approach

To investigate functional results of either one- or two-staged free muscle transplantation the scutuloauricularis model in the New Zealand white rabbit was used. Thirty rabbits were allocated to two groups with 15 animals each. In Group 1 (one-stage approach) peroneus brevis (PB) was harvested as a free muscle graft with a 7cm long motor branch. The graft was positioned instead of right scutuloauricularis (SCUT) and its vascular supply microsurgically re-established. The motor branch was transferred to the contralateral side and its proximal end coapted to the cut facial motor branch to left SCUT. Before nerve coaptation biopsies were harvested from the cut motor branch for morphological analysis. In Group 2 (two-stage approach) a 7cm long saphenous nerve graft was taken and coapted to the cut motor branch of SCUT and crossed over to the contralateral side. Nerve specimens from the cut motor branch were taken. Eight months later the free transplantation of PB was performed and its motor branch coapted to the distal end of the cross-over nerve graft. After a total time period of 13 months the final experiments were carried out in each group. Maximal tetanic tensions in reinnervated PB were measured and biopsies of muscle grafts together with nerve biopsies from the distal part of the motor branch were harvested for morphological analysis. Muscle grafts of Group 1 revealed tetanic tension values of 12.5N (SD 3.1) in comparison to 10.6N (SD 3.5) obtained in Group 2. This difference was not statistically significant (p=0.303). In Group 1, the amount of regenerated nerve fibers counted at the distal motor branch site (mean: 2798, SD 1242) was significantly higher (p=0.008) than in Group 2 (mean: 1138, SD 1004). Muscle graft morphology revealed significantly less Type I fibers (p=0.016) and more Type IIb/d fibers (p=0.011) in Group 1 compared to Group 2. However, the overall amount of perimysial connective tissue showed no significant difference in both groups (p=0.478). Free muscle transplantation in a one-stage approach offers similar functional results in comparison to the two-stage approach. Although muscle grafts of the one-stage transplantation underwent a longer period of denervation similar contents of perimysial connective tissue could be observed.

Intra-individual comparison between openand 2-portal endoscopic release in clinically matched bilateral carpal syndrome

Based upon bilateral carpal tunnel syndrome (CTS) we undertook a prospective randomised intra-individual comparison between open (OR) and 2-portal endoscopic release (2-PER) to establish if there is any demonstrable advantage in undertaking either technique in a 1 year follow-up. Ten patients with bilateral CTS were enrolled in this study and underwent a 2-PER on the one and an OR with two minimised incisions on the contralateral hand. Both hands were examined pre- and postoperatively after 2, 4, 6 and 12 weeks and after 6 and 12 months, respectively. Preoperatively both hands revealed statistically no significant differences in all the parameters recorded. Comparing both techniques no significant differences could be detected in the follow-up period. Nevertheless, both techniques showed significant improvements in the severity of symptoms and pain, in sensory nerve testing and in electro-diagnostic parameters, when comparing pre- with postoperative data after 1 year. The endoscopic approach revealed no distinct advantages over the open technique not only in the late but also in the early postoperative follow-up period when performing intra-individual comparison. Considering the higher complication rate and costs when performing 2-PER the OR with two minimised incisions seems to be a good alternative in order to keep the recovery period as short as possible.

Use of subatmospheric pressure therapy to prevent burn wound progression in human: first experiences

Thermal trauma causes two different types of injuries within the burn wound. First, an immediate and irreversible injury, and, second, a delayed and partly reversible injury. It is a very common observation in burned patients that areas that initially seemed to be partial thickness burns have to be regarded as full thickness within the next day or days. The impairment of blood flow within the zone of stasis is due to the impairment of the vascular patency at the microvascular level. This progression is closely correlated to the degree of oedema formation. The aim of the study was to demonstrate that applied, controlled subatmospheric pressure is useful to prevent the progression of partial thickness burn injuries. Therefore, seven patients (mean age, 44.2 years; S.D., 22.4 years) with bilateral partial thickness hand burns were included into this treatment protocol. The more intense injured hand was treated with controlled applied subatmospheric pressure (V.A.C. (ATS)), the other and less injured hand conservatively by use of silver sulphadiazine creme. In the V.A.C.-treated hand a massive hyperperfusion was observed, being a possible reason for the prevention of burn progression. Moreover, a noteworthy amount of fluid was removed from the burn wound and a clinically obvious oedema reduction was observed in comparison to the contralateral side. In summary, we are of the opinion, that patients with partial thickness or mixed thickness burn may benefit from the application of subatmospheric pressure by reducing oedema formation and increasing perfusion.

The influence of dressings and ointments on the qualitative and quantitative evaluation of burn wounds by ICG video-angiography: an experimental setup

Burn wound depth is difficult to determine. Even for experienced investigators the exact differentiation between superficial and deep dermal burns is not always possible. Therefore, methods for objective and reproducible measurements estimating the depth of burn wounds are of great clinical interest. One technique that appears to be able to differentiate between superficial and deep dermal burn wounds is ICG video-angiography. Since burn wounds are often covered with dressings and ointments or soiled with blood, it is necessary to evaluate the influence of these substances on ICG video-angiography and its performance as a measurement method. The most commonly used ointments and dressings were tested. All studied substances had a massive influence on ICG video-angiography and its measurements. They caused decreases by absorption of up to 63 +/- 36% and thereby falsely reported deeper burn wounds. The results of this study, suggest that in clinical practice, all dressings, ointments and blood should be completely removed at least 10 min prior to measurement by ICG video-angiography to gain exact and reproducible results.

Der Einsatz der V.A.C.®-Therapie bei der Verminderung des „Nachbrennens”: Erste Ergebnisse in der Verbrennungsbehandlung

Thermal injury applied to living tissue results in zones of injury. Cell death is complete in the zone of coagulation. Beneath this area, there is the zone of lesser injury, where most of the cells are initially viable. If this zone of stasis is not reversed, the burn wound will progress. One of the major aspects to prevent progression is to reduce the edema formation and to preserve microcirculation. We present our first experiences to prevent the progression by use of topical negative pressure. Within the last months, all patients with bilateral partial thickness hand burns were included into this treatment protocol. Within one patient, one hand was treated with the V.A.C. (KCI, Austria), the contra lateral one by use of Flammazine (Smith and Nephew, Germany). Our first observations and data indicate, that both important factors (edema and microcirculation) could be influenced positively by use of the V.A.C.

Serum cholesterol and triglycerides: potential role in mortality prediction

The present study was performed in order to evaluate the diagnostic usefulness of serial cholesterol and triglycerides measurements in patients with severe burns. One of the main objective was to find out if these parameters are clinically relevant to determine the morbidity of a burn patient and thereby the patient's outcome. In 220 patients with thermal injuries, cholesterol and triglyceride concentrations were measured daily. Blood samples were drawn immediately upon admission and thereafter daily until patient's discharge or death. For both parameters, a characteristic course was noted: in the group of non-survivors, a decrease of cholesterol prior to death was noted, while survivors, increased prior to discharge. The time courses of both groups (survivors-non-survivors) differed statistically significantly (P=0.0068). An increase in triglycerides was observed in all non-survivors prior to death, but in the group of survivors triglycerides remained more or less unchanged. These time courses also had statistically significant differences (P=0.0004). In our 220 patients, changes in cholesterol (P<0.0001, hazard ratio 1.02) and triglycerides (P=0.0008, hazard ratio 1.01) had comparable capability to predict the severity of a burn trauma and thereby its outcome than the established parameters in the treatment of burns (total body surface area burned, age, inhalation). We consider the serial measurements of cholesterol and triglycerides as clinically relevant to assess the morbidity of a patient and thereby to estimate the patient's outcome. We think that these serial measurements provide useful information for the clinician treating patients with severe burns.

Indocyanine green video angiographies help to identify burns requiring operation

The key decision in the treatment of thermal injuries is the determination of the depth of the burn wound and the resultant decision on treatment options. The trend in the treatment of deep dermal and full thickness burns is toward very early excision and grafting to reduce the risk of infection, decrease scar formation, shorten hospital stay, and thereby reducing costs. Traditionally, this has involved serial clinical examinations, which involves primarily subjective judgment. Various objective examination techniques, supplementing the clinical diagnosis, have been suggested, but none has yet achieved widespread clinical acceptance. It has frequently been postulated that the blood flow in injured tissue indicates the extent of tissue damage. In this study, the clinical and scientific impact of indocyanine green (ICG) video angiography was tested in 20 patients. A wide range of depth of injury and etiology was included and analyzed. In all cases considered, video angiography was possible. The measurements and observations correlated well with the actual burn depth, which was assessed clinically (pre- and intraoperative assessment) and histologically (biopsies). In conclusion, ICG video angiography seems to be a practical method to describe vascular patency in a burn wound. The results indicate that ICG fluorescence angiography is a practical, accurate, and effective adjunct to clinical methods for estimating burn wound depth and thereby to assist in the rational assessment of treatment options. Furthermore, it allows an objective, qualitative and quantitative observation of the dynamic changes in burn wound depth, which are observed during the acute post-burn period, thereby indicating optimal timing of the first operation.

The influence of timing on the functional and morphological result after nerve grafting: an experimental study in rabbits

Clinical experience and experimental work in sheep have shown that a two-stage approach to restoring muscle function with a long nerve graft and free muscle grafting seems to be more beneficial than a one-stage approach. Based on a standardised experimental protocol, one-stage and two-stage nerve grafting approaches in rabbits were compared, and the actual differences in muscle force, together with morphological data, were calculated. In 20 rabbits the saphenous nerve was used as a 7 cm nerve graft. Animals were separated into two groups. In group 1, 10 rabbits underwent a one-stage approach to reinnervate the rectus femoris muscle. In the left hindlimb, the proximal end of the graft was coapted to the cut motor nerve branch of the vastus medialis muscle, and the distal end was coapted to the nerve branch of the rectus femoris muscle. In group 2, 10 rabbits underwent a two-stage approach, leaving the distal end of the nerve graft unconnected to the rectus femoris muscle in the first stage. In the second stage, this end was coapted to the freshly cut motor nerve branch of the rectus femoris muscle. After 15 months, the maximum tetanic tensions in the reinnervated rectus femoris muscle and the contralateral unoperated muscle were determined. The graft and the motor branch distal to the graft were biopsied in order to count the number of regenerated myelinated nerve fibres. The mean+/-s.d. maximum tetanic tensions in the reinnervated rectus femoris muscles were 10.6+/-4.9 N in group 1 and 21.4+/-1.1 N in group 2. Compared with the unoperated side, the muscle force following denervation and reinnervation was 38.3% in group 1 and 58.9% in group 2 (P=0.01). The mean+/-s.d. numbers of regenerated myelinated nerve fibres distal to the graft in the rectus femoris muscle branch were 737+/-340 in group 1 and 1487+/-1004 in group 2 (P=0.05). These results show that the neurotrophic effect of an immediately connected target organ is far outweighed by the adverse effect of the longer period of muscle denervation. Therefore, nerve grafting and muscle transplantation should not be performed in the same operation.

Continuous free-flap monitoring with tissue-oxygen measurements: three-year experience

Early recognition of flap failure is a prerequisite for flap salvage. Many methods are used to monitor free flaps. The time interval for re-establishing vascular patency is the limiting factor for a successful revision. Prompt re-operation and a rapid and sufficient correction of the microvascular anastomosis are necessary to maintain flap viability. The Licox Catheter pO 2 Micro-Probe instrument is used for continuous determination of oxygen partial pressure (pO 2 ) in body fluids and tissue (p ti O 2 ). Over a period of 3 years, 60 free tissue transfers to head and neck, trunk, and upper and lower extremities were monitored using the Licox Catheter Probe System. The flexible Licox Catheter pO 2 Micro-Probe detected circulatory changes and failure in all cases, with no false positives or negatives. In all cases in which the arterial pedicle failed, the p ti O 2 dropped rapidly; in cases of venous insufficiency, the p ti O 2 value decreased more or less slowly. In all failing flaps, a p ti O 2 decrease of 10 mmHg within a half-hour, or a p ti O 2 drop below 10 mmHg was observed. These are observations which are useful as precise indicators for vascular complications and flap failure. Based on the authors' observations and data, the Licox probe is a sensitive and accurate monitoring system for all types of free flaps.

Functional and morphometric evaluation of end-to-side neurorrhaphy for muscle reinnervation

This study was undertaken to quantify the effect of motor collateral sprouting in an end-to-side repair model allowing end organ contact. Besides documentation of the functional outcome of muscle reinnervation by end-to-side neurorrhaphy, this experimental work was performed to determine possible downgrading effects to the donor nerve at end organ level. In 24 female New Zealand White rabbits, the motor nerve branch to the rectus femoris muscle of the right hindlimb was dissected, cut, and sutured end-to-side to the motor branch to the vastus medialis muscle after creating an epineural window. The 24 rabbits were divided into two groups of 12 each, with the second group receiving additional crush injury of the vastus branch. After a period of 8 months, maximum tetanic tension in the reinnervated rectus femoris and the vastus medialis muscles was determined. The contralateral healthy side served as control. The reinnervated rectus femoris muscle showed an average maximum tetanic force of 24.9 N (control 26.2 N, p = 0.7827), and the donor- vastus medialis muscle 11.0 N (control 7.3 N, p = 0.0223). There were no statistically significant differences between the two experimental groups (p = 0.9914). The average number of regenerated myelinated nerve fibers in the rectus femoris motor branch was 1,185 +/- 342 (control, 806 +/- 166), and the mean diameter was 4.6 +/- 0.6 microm (control, 9.4 +/- 1.0 microm). In the motor branch to the vastus medialis muscle, the mean fiber number proximal to the coaptation site was 1227 (+/-441), and decreased distal to the coaptation site to 795 (+/-270). The average difference of axon counts in the donor nerve proximal to distal regarding the repair site was 483.7 +/- 264.2. In the contralateral motor branch to the vastus medialis muscle, 540 (+/- 175) myelinated nerve fibers were counted. In nearly all cross-section specimens of the motor branch to the vastus medialis muscle, altered nerve fibers could be identified in one fascicle distal and proximal to the repair site. The results show a relevant functional reinnervation by end-to-side neurorrhaphy without functional impairment of the donor muscle. It seems to be evident that most axons in the attached segment were derived from collateral sprouts. Nonetheless, the present study confirms that end-to-side neurorrhaphy is a reliable method of reconstruction for damaged nerves, which should be applied clinically in a more extended manner.

Histomorphology of rabbit thigh muscles: establishment of standard control values

The thigh muscles of New Zealand White (NZW) rabbits are frequently used in experimental surgery, particularly for evaluation after reinnervation or ischaemia. Although histomorphometric analyses are regularly performed, morphological data for untreated thigh muscles in previously unoperated animals are not available. Specimens from the rectus femoris (RF), vastus medialis (VM) and adductor magnus (AM) muscles from both thighs were harvested in 7 untreated rabbits and were processed for histomorphometric evaluation. The right RF and VM were harvested in a further 5 rabbit hindlimbs after experimental denervation and reinnervation of the contralateral RF and subsequently processed for histomorphometric analysis. Muscle fibre type distribution, diameter and connective tissue content were evaluated on serial transverse cryosections reacted for ATPase and NADH tetrazolium reductase activity and statistical analysis was performed. In all untreated animals RF revealed the highest proportion of type I muscle fibres (right: 8.4+/-4%, left: 11.4+/-4.9%), whereas VM showed the highest percentage of IIa fibres (right: 31.9+/-5.5%, left: 28.3+/-7.8%) and AM the highest proportion of IIb/d fibres (right: 80.5+/-8.6%, left: 84.4+/-6.3%). Fibre type distribution and diameter in rabbits after contralateral experimental operations revealed a statistically significant difference from the data obtained in bilaterally untreated animals. Knowledge of the morphology of untreated muscles is fundamental to the understanding of changes induced by intervention to the ipsi and/or contralateral thigh muscles.

[Effect of transplant length on functional and morphologic outcome of nerve transplantation--an experimental study]

BACKGROUND

The present study was done in order to clarify whether the sometimes poor results after the use of long grafts for nerve reconstruction are due to the length of the graft itself or due to the concomitant big defect in the soft tissues necessitating the use of long grafts.

METHODS

In 22 rabbits, the saphenous nerve was used as a nerve graft. Animals were separated into three groups with different lengths of the grafts, namely 3 cm (group 1), 5 cm (group 2) and 7 cm (group 3). In one hindlimb, the proximal end of the graft was coapted to the motor nerve branch of vastus medialis. In a second step, the distal end of the graft was coapted to the nerve branch of rectus femoris. After a total period of 15 months the maximum tetanic tensions in the reinnervated rectus femoris and in the contralateral untreated muscle were determined. Biopsies of the graft and the motor branch distal to the graft were taken in order to count the number of regenerated myelinated nerve fibers.

RESULTS

The average maximum tetanic tension in the rectus femoris muscle reinnervated by the 3 cm long graft was 27.2 N; in group 2 the force amounted to 20.4 N. In group 3, the maximum force was 17.6 N, which meant an average loss of 29% compared to the contralateral untreated muscle. In accordance with the functional results, the mean number of regenerated myelinated fibres in the rectus femoris motor branch decreased from 1683 in group 1 to 1136 in group 3.

CONCLUSIONS

The results show that the length of the graft influences the results after nerve grafting to a certain extent, but a combination of other factors like concomitant soft tissue injury and destroyed target organs may also be responsible for some of the poor results after the clinical use of long nerve grafts.

The impact of a muscle target organ on nerve grafts with different lengths--a histomorphological analysis

The present study was done in order to evaluate the influence of a target muscle on the regenerative processes in long nerve grafts. In 21 rabbits the saphenous nerve was used as a nerve graft and coapted to the cut motor nerve of vastus medialis. The animals were separated into three groups with different graft lengths, namely 3, 5, and 7 cm. In a second stage the distal end of the graft (Graft.dist.) was coapted to the motor branch of rectus femoris. Cross sections of the normal vastus nerve and the Graft.dist. before and 7 months after the connection to rectus femoris were analyzed histomorphometrically. Before coaptation to the target organ mean fiber number in the Graft.dist. of the 3-cm-long grafts was 3380 and decreased to 2413 in the 7-cm-long grafts. Seven months after coaptation the results showed a statistically significant decrease of fibers in the Graft.dist. of group two and three and a distinct decrease of the fibers in group one. Summarizing, in a two-stage nerve grafting procedure the reinnervation of the muscle target organ leads to a down-regulation of fibers in the distal end of short and long nerve grafts.

The influence of the graft length on the functional and morphological result after nerve grafting: an experimental study in rabbits

Clinical experience shows that the results after the use of long nerve grafts for reconstruction are sometimes poor. Nevertheless several authors have stressed that the concomitant big defect in the soft tissues necessitating the use of long grafts is the reason for some of the failures. In 22 rabbits the saphenous nerve was used as a nerve graft. Animals were separated into 3 groups with different lengths of the grafts, namely 3 cm (group 1), 5 cm (group 2) and 7 cm (group 3). In the left hindlimb the proximal end of the graft was coapted to the cut motor nerve branch of vastus medialis. In a second stage the distal end of the graft was coapted to the nerve branch of rectus femoris. After a total period of 15 months the maximum tetanic tension in the reinnervated rectus femoris and in the contralateral unoperated muscle was determined. Biopsies of the graft and the motor branch distal to the graft were taken in order to count the number of regenerated myelinated nerve fibers. The average maximum tetanic tension in the rectus femoris muscle reinnervated by the 3 cm long graft was 27.2 N, in group 2 the force was 20.5 N. In group 3 the maximum force was 17.6 N, which meant an average loss of 29% compared to the contralateral unoperated muscle. The mean number of regenerated myelinated fibres distal to the graft in the rectus femoris motor branch was 1683 in group 1 and decreased to 1137 in group 3. The results show that the length of the graft influences the results after nerve grafting to a certain extent, but a combination of other factors like concomitant soft tissue injury and destroyed target organs may also be responsible for some of the poor results after the clinical use of long nerve grafts.