Carsten M. Philipp

Ten years of laser treatment of congenital vascular disorders: techniques and results

During the period of January 1984 - July 1993, we have treated 611 children with more than 2000 lesions of congenital vascular disorders (CVD) such as hemangiomas and vascular malformations. This number does not include the patients with port wine stains, which also have been treated by means of laser. Most of the CVD patients (n equals 467) presented hemangiomas of the face, the anogenital region, and the extremities, some were located in the trachea or mouth or in the urogenital tract. All of these hemangiomas were growing prior to intervention or showed complications such as bleeding, ulceration, superinfection, or obstruction. Nearly a quarter (n equals 144) of the patients presented vascular malformations, either of singular vessel type involvement or of mixed vascular genesis (venous, arterio- venous, veno-lymphatic or lymphatic) with various complications like tracheal obstruction or recurrent thrombophlebitis. According to our step program, which is based on a clinical classification, the hemangiomas were treated as early as possible, while the vascular malformations were only treated with laser when no other therapeutic technique (embolization, resection) was suitable. All patients were referred for laser treatment from other centers. The lasers used were Nd:YAG and Argon lasers with transcutaneous application with or without continuous ice-cube surface cooling or interstitial laser application. The treatments were performed either on in- or outpatient basis according to age, localization and with good to excellent results in most cases and a complication rate of less than 2%.

Laser Therapy of Haemangiomas and Vascular Malformations – Techniques and Strategies

Summary Lasers have been used in the treatment of haemangiomas since the early 1980s. Several study groups have reported good results, others have been less enthusiastic and emphasized other treatments like cryosurgery. We reviewed our experience with the use of laser therapy in treating complicated haemangiomas of infants. During a 15-year period, 1117 infants with haemangiomas were treated with the Nd:YAG laser. The lesions reported were particular troublesome because of significant cosmetic disfigurement, maceration or ulceration, bleeding, and of potential functional impairment. Superficial findings were treated using was a transcutaneous application with local ice cube cooling to protect the overlying skin. All deep-seated lesions were treated with interstitial laser irradiation. In trachaeal haemangiomas endoscopic laser destruction is an alternative to tracheostomy with good functional results and comparable or less morbidity. Overall, excellent results were achieved in 41% of infants and good results occured in 51%. On the basis of our results we conclude that laser therapy may successfully prevent enlargement and promote involution of haemangiomas with minimal adverse effects. Therapy should be initiated as early as possible, when lesions are relatively flat, for optimal results.

Management of ALA-PDT Induced Pain Sensations

Summary In dermatology, photodynamic therapy (PDT) with topically applied 5-aminolevulinic acid (ALA) has proved to be an alternative option for the treatment of malignant and benign skin lesions. The main advantages compared with other therapeutical options are the excellent cosmetic results achieved and the low number of side effects. One of the main acute side effects is pain arising during ALA-PDT lasting for several hours. Pain seems to depend on the light source used (lamp vs. laser, wavelength), power or energy density applied, diameter of the irradiated field and localisation. Our hypothesis of the mechanism of pain induction postulates that the pain may be the result of a damage to epidermal nerve endings which had accumulated ALA or protoporphyrin IX (PPIX) in their membrane during application time of ALA. According to this hypothesis methods for pain reduction should deal with a minimising accumulation of PPIX in nerve endings/membranes, desensitisation of nerve endings or blockade of the nerve depolarisation. Local (topically, i.c., s.c.) or regional (s.c. blockade) anaesthesia, fan, water spray, air stream, pre-cooled air stream, systemic application of NSAID or opioids alone or in combination were used for pain reduction with different success. The number of studies dealing with the evaluation of ALA-PDT induced pain and methods for pain reduction is very low despite it is a problem of great importance. In our clinical practice pain reduction with pre-cooled air is used with great success and found general acceptance by the patients. Application of regional anaesthesia was only necessary in special regions e.g. the ear and opioids were mostly given to anxious patients. In general, selecting or developing modalities for pain reduction one should consider that a non-invasive technique such as the ALA-PDT should necessarily demand a non-invasive modality for pain reduction such as a pre-cooled air stream.

Interstitial Laser Treatment of Venous Malformations

Summary Objective: Venous malformations are aside from hemangiomas the most common vascular lesions observed in the pediatric age group. While interstitial Nd:YAG laser treatment was first used to treat hemangiomas in infancy, the mechanism of this treatment also can be used for venous malformations to reduce bulk and hypervascularisation, and improve contour and function. Study design: We reviewed our experience with the use of interstitial Nd:YAG laser therapy in treating complicated venous or mixed malformations. The lesions reported were particular troublesome because of significant cosmetic disfigurement, maceration or ulceration, bleeding, coagulopathy, painful swelling, and of potential functional impairment. During a 15-year period, 176 patients with predominantly venous malformations were treated by interstitial Nd:YAG laser treatment, and 157 of the 176 patients were treated additionally by transcutaneous Nd:YAG laser treatment with local ice cube cooling to protect the overlying skin. By using interstitial laser treatment, the laser beam was transmitted using a 0.6 mm bare fiber that was placed through an 16G abbocath into the lesion to be treated. The laser energy ranged from 5 W to 8 W in continuous mode. Color-coded duplex sonography was used for monitoring the procedure. Treatments were done under general anesthesia. Results: Overall, excellent results were achieved in 43% of patients and good results occured in 52%. In 5% treatment was deemed to have failed. Complications included paresthesia, dysesthesia, mild trismus, and local motoric plegia. All complications were transient and disappeared completely. Overall, satisfaction was high because of clear reduction of complaints, and all but 1 patient would have laser treatment again. Conclusions: On the base of our results we conclude that interstitial Nd:YAG laser treatment may successfully prevent enlargement and promote improvement with flattening of the lesion, less swelling, and improvement in the vascular red or bluish hue with minimal adverse effects.

Interstitial Thermotherapy (ITT) Using Nd:YAG Laser as a New Option for the Treatment of Neuroma

Summary Interstitial Laser Induced Thermotherapy (LITT) using Nd:YAG-laser proved to be an alternative or additive method for the treatment of nodular tumors and metastasis which could not be treated with conventional surgical resection or only with high risk for the patient. Because of the high recurrence rate of painful neuroma after surgical removal, which occasionally develop after surgical intervention or after traumatic injury of nerves often are a therapeutically challenge. Therefore, there is a demand to think of new strategies and to explore methods for the treatment of neuroma. One patient with clinical findings of a neuroma was only treated with LITT whereas two other patients with histological confirmed neuroma received interstitial laserthrapy after all attempts to remove the neuroma by common surgical methods were in vain. All patients were irradiated using Nd:YAG-LITT. After an observation period of 4 to 7 years respectively no recurrence of the neuroma occurred and the patients are free of any clinical symptoms. The three cases suggest that LITT using Nd:YAG-laser could be an alternative method to common surgical methods. LITT is minimal invasive, easily to perform and clearly reduced the spectrum of side effects known from the common surgical techniques. Nevertheless, further studies are necessary to confirm our findings and to evaluate laser parameters for optimised LITT of neuroma.

Laser-induced thermotherapy of benign and malignant tumors controlled by color-coded duplex sonography

Since 1984 we use the interstitial application of laser induced thermotherapy (LITT) for the treatment of congenital vascular disorders (CVD) such as hemangiomas and vascular malformations. In most of the procedures a 600 micron core bare fiber is used to deliver the radiation of a cw Nd:YAG laser emitting at 1064 nm into the diseased tissue. As most of the CVD treated this way are located subcutaneously, the localization of the fiber and the interstitial laser coagulation (ILC) is controlled by transillumination and palpitation of the heat expansion of the skin surface, this way a crepitation can also be detected during the ILC. As the ILC in deeper body structures cannot be controlled directly we use color coded duplex sonography (CCDS), both for diagnostic and treatment control. In the procedures where we use the B-scan image for puncture control, a color signal is displayed representing tissue movements. These movements caused by degasification and vapor are those detectable as crepitations when using direct control. The color signal starts, changes, and moves in a reproducible pattern following the heat distribution and the subsequently occurring degasification in the tissue. Also the changes in perfusion are detectable by the means of CCDS. The precise extent of the coagulation is visible in the B-scan several minutes after laser exposure. The clinical experience and an extensive experimental evaluation has proven that CCDS is a valuable real time method to monitor the tissue reaction in ILC-procedures. For two years we have performed ILC-procedures with CCDS control in patients with CVD (n equals 65) successfully. Because of its reliable imaging and the clinical advantages recently we applied this type of ILC-control to the palliative treatment of nonresectable primary and secondary liver tumors (n equals 3) and subcutaneous metastases of mamma carcinoma. (n equals 6).

Laser Therapy of Vulval and Cervical Dysplasias

Summary Vulval and cervical dysplasias have been treated until up today by surgery causing scars, sexual discomfort and psychological problems. Within the last few years, several laser therapies and optical diagnostic methods have been developed to treat affected women more differenciated with regard to the clinical and histological findings. Large surgeries can be avoided, healing times are shorter, pain and discomfort after treatment are minimized. HPV-induced lesions can be treated after laser with Imiquimod, an immunomodulator with the intention to irradicate the virus and to avoid recurrences. Optical diagnostics with flourescence technique is currently under evaluation for non-invasive detection of cervical pathology. CO 2 -laser conization is etablished as one of the present treatment strategies, either using a colposcopic guided beam or free hand surgery.

Laser Therapy of Human Papilloma Virus Associated Genital Warts

Summary Introduction: Condylomata acuminata are caused by the Human Papilloma Virus Types 6 and 11. This sexually transferred disease is one of the most widespread diseases in the world and its incidence is growing. Many different treatments exist, but the results are not satisfactory because of the high relapse rate. Patients and methods:During the past five years we treated 437 patients with genital warts with either a CO2 laser or a Nd:YAG laser, depending on the localisation. A detailed examination preceded every treatment. In cases where the lesions could not be clearly recognised as condomylata, we carried out an ALA-D-Light diagnosis and took biopsies. Results:We treated 280 males and 157 females. 80% of the males and 30% of the females suffered from intraanal lesions. Three males and one female had deep internal urethral lesions and 22% of all patients displayed genital warts at the urethral ostium. 12% of the women had portio lesions and in 4% of the females and in three men we detected dysplasias using the ALA-D-Light diagnosis system. The total relapse rate was of 7%. Discussion:The widespread nature and high infection rate of genital warts together with their possible complications make a reliable and adequate treatment essential. Because of the many phenotypes of condylomata, diseases like dysplasias have to be excluded. Summary:The use of lasers in the treatment of genital warts has helped to reduce the rate of relapse. Appropriate and discriminatory diagnostics prior to treatment lead to better results. Patients acceptance is high because they often can be treated as outpatients, suffer only minor inconvenience and good cosmetic results are achieved.

MR-guided laser-induced thermotherapy of head and neck tumors

Interstitial laser-induced thermotherapy (LITT) is a recently developed, minimally invasive technique for local tumor destruction within solid organs. Low-power laser, with delivery of light energy through thin optical fibers, results in a well-defined area of coagulative necrosis. Thus, laser can destroy tumor by direct heating, while greatly limiting damage to surrounding structures. Experimental work has shown that a well defined area of coagulative necrosis is obtained around the fiber tip, with minimal damage to surrounding structures. Pilot clinical studies have demonstrated that this technique is practical for the palliation hepatic tumors. The success of LITT is dependent on delivering the optical fibers to the target area, real time monitoring of the effects of the treatment and subsequent evaluation of the extent of thermal damage. The key to achieving these objectives is the imaging methods used. The magnetic resonance (MR) findings of LITT in the experimental setting have been described, but the clinical role of MRI during and after LITT has been only described in a small series of patients.

Studies on the optimized fluorescence diagnosis of tumours by comparing 5-Ala induced xenofluorescence and autofluorescence intensities of a murine tumour-non tumour tissue system cultivated on the CAM

The in vivo model of the chorioallantoic membrane of fertilized chicken embryos (CAM) was employed for studying the fluorescence characteristics of tumor tissue in comparison with non tumorous tissue. Tumors were grown from the murine fibrosarcoma cell line SSK II and murine 3T3 fibroblasts (clone A31) were used for cultivating non tumorous tissue. Autofluorescence and xenofluorescence intensities induced by 5-aminolaevulinic acid (5-ALA) were compared. Exogenous administration of 5-ALA, an early precursor in haem synthesis, induces accumulation of endogenous photoactive porphyrins, in particular protoporphyrin IX (PpIX). Fluorescence investigations were performed after 3-4d of incubation, when the tissues had reached macroscopically three dimensional stages of growth. Fluorescences were excited with a HBO-X 100 W lamp (Carl Zeiss) at a wavelength (lambda) equals 405 plus or minus 5 nm. Emissions were detected in the spectral range above 630 nm and visualized by real time digital image processing (Argus 10, HAMAMATSU) using an ICCD camera (HAMAMATSU). After administration of 0.4 mmolar 5-ALA solution to the CAM inoculated tissues the SSK II tumors exhibited higher fluorescence intensities than the 3T3 non tumorous tissues. Autofluorescence intensities of both types of tissues were not distinguishable. Furthermore, the effects of several biochemicals on the xenofluorescence intensities of the fibrosarcoma and fibroblast tissues were investigated.