Midtrimester maternal serum screening after multifetal pregnancy reduction in pregnancies conceived by in vitro fertilization

BACKGROUND: The rising incidence of esophageal adenocarcinoma in western countries requires a new strategy in the management of dysplasia in Barrett's esophagus. Esophagectomy, which has high morbidity and mortality rates, has been recommended to treat patients with severe dysplasia. Strictly superficial laser coagulation with tissue ablation therefore is a desirable option for the management of dysplasia in Barrett's esophagus because the tissue to be ablated is only about 2 mm thick. Potassium-titanyl-phosphate (KTP) laser light with a wavelength of 532 nm is preferentially absorbed by hemoglobin and therefore combines excellent coagulation with limited tissue penetration. We report first clinical results with KTP laser superficial vaporization of dysplasia and early cancer in Barrett's esophagus. METHODS: Eight men and 2 women 43 to 84 years of age with short segments of Barrett's esophagus or traditional Barrett's esophagus and histologically proved low-grade (n = 4) and high-grade (n = 4) dysplasia or early adenocarcinoma (n = 2) were selected for this pilot study. For all patients thermal endoscopic destruction was conducted with a frequency-doubled neodymium:yttrium-aluminum-garnet (Nd:YAG) KTP laser system. Laser therapy was performed by means of the free-beam method with coaxial insufflation of gas. An average of 2.4 sessions per patient were required for ablation of the Barrett's mucosa. RESULTS: Two to three days after laser treatment the response of the ablated mucosa was assessed with endoscopy and biopsy. Samples taken showed fibrinoid necrosis of the mucosal layer. A complete response was obtained for all 10 patients. Replacement by normal squamous cell epithelium was induced in combination with acid suppression therapy of up to 80 mg omeprazole daily. No complications occurred. In two patients biopsy showed specialized mucosa beneath the restored squamous cell epithelial layer. Follow-up times were as long as 15 months (mean value 10.6 months). CONCLUSIONS: KTP laser destruction of Barrett's esophagus induced mucosal regeneration with normal squamous cell epithelium in combination with acid suppression. Limitation of the depth of thermal destruction in Barrett's esophagus minimizes risk for perforation or stricture formation. KTP laser ablation of Barrett's esophagus seems to be feasible and safe in short segments of Barrett's esophagus with dysplasia or early cancer.     

Effects of organophosphorus, carbamate, pyrethroid and organochlorine pesticides, and a heavy metal on survival and cholinesterase activity of Chironomus riparius Meigen

BACKGROUND & AIMS: The first therapeutic experiences with the conventional photosensitizer dihematoporphyrinester in the treatment of Barrett's esophagus show the curative potential of photodynamic therapy (PDT). The aim of this study was to test 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX, a photosensitizer with a high mucosa specificity without phototoxic side effects on the skin, as a new form of PDT. METHODS: Thirty-two patients (mean age, 68.5 years) with histologically proven high-grade dysplasia (n = 10) and mucosal cancer (n = 22) in Barrett's esophagus were treated. Four to 6 hours after oral ingestion of 5-ALA (dose, 60 mg/kg body wt), irradiation was conducted with a dye laser system (635 nm) with a light dose of 150 J/cm2. The patients received 20-80 mg omeprazole daily after PDT. RESULTS: High-grade dysplasia was eradicated in all patients (10 of 10), and mucosal cancer was eliminated in 17 of 22 patients (77%) at a mean follow-up of 9.9 months (range, 1-30 months). All tumors < or = 2 mm in thickness were completely ablated (17 of 17). The method-related mortality and morbidity was 0%. CONCLUSIONS: Severe dysplasia and thin (< or = 2 mm) mucosal cancer of Barrett's esophagus can be completely ablated. PDT might offer a minimally invasive treatment modality as an alternative to esophagectomy.     

Lasers in urology

Ever since Mulvany first described use of Ruby laser for lithotripsy, urologists have been exploiting every possible application of this technology. Laser lithotripsy in the 1980s and now laser prostatectomy in the 1990s have dominated laser usage in urology. Applications of lasers for superficial lesions (e.g., condylomata acuminata and carcinoma of penis) have found an established role. Interests in laser welding, photodynamic therapy and fluorescence continues to grow and evolve. The laser industry at the same time is striving to provide more efficient lasers. High power lasers (Holmium:YAG, KTP:YAG) and laser machines combining double wavelengths (Nd:YAG and KTP, Ho: YAG and Nd:YAG) are commercially available. Diode lasers with their portability and reliability qualities can now provide high output powers in various wavelengths. Here, we have reviewed different lasers, laser tissue interaction and clinical laser applications relevent to urology.     

High-grade dysplasia in Barrett's oesophagus

BACKGROUND: The management of high-grade dysplasia (HGD) in Barrett's oesophagus is a controversial and challenging problem. METHODS: An up-to-date review of the literature has been made using Index Medicus, the Medline database, and cross-referencing of major articles on this subject. RESULTS: Diagnosis should be confirmed by a second expert pathologist. Repeat multiple jumbo biopsies and brushings need to be taken to reduce sample error and exclude associated invasive cancer. In young fit patients the advantages of surgery outweight the disadvantage of missing an early adenocarcinoma. Continued endoscopic surveillance may be more appropriate in elderly patients. New technology has increased the number of options. Early results of laser and multipolar electrocoagulation ablation of Barrett's epithelium are encouraging. Photodynamic therapy appears to be ideally suited to HGD and early cancers. CONCLUSION: A selective approach to the management of HGD on an individual patient basis should be adopted.     

Infrahepatic terminolateral cavo-cavostomy as a rescue technique in complicated "modified" piggyback liver transplantation

BACKGROUND: Transurethral visual laser ablation of the prostate (VLAP) has been established as an alternative method for the treatment of benign prostatic hyperplasia (BPH). However, most VLAP procedures utilize only a neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. Since a potassium-titenyl-phosphate (KTP) laser offers limited tissue penetration, KTP can be safely utilized to excise part of the obstructing prostatic tissue. This study assessed the interaction between KTP vaporization and YAG coagulative ablation to determine the safety and efficacy of VLAP utilizing a combined KTP/YAG treatment. METHODS: Forty patients with bladder outlet obstruction secondary to BPH were treated with VLAP using a KTP/YAG laser. The laser light was delivered by an angle delivery device. RESULTS: Most cases demonstrated a significant improvement in routine subjective and objective parameters (AUA symptom score, peak flow rate, average flow rate, and amount of residual urine). No significant complications relating to this procedure were reported, however, 4 patients experienced postoperative acute urinary retention. CONCLUSION: KTP/YAG laser ablation of the prostate is safe and effective for the treatment of BPH.     

Barrett's esophagus, high-grade dysplasia, and early adenocarcinoma: a pathological study

OBJECTIVES: In Barrett's esophagus, early adenocarcinomas are often missed on endoscopic biopsy. We therefore examined the distribution and extent of dysplasia and carcinoma in the resected esophagus for comparison with the preoperative biopsy findings. METHODS: Patients whose endoscopy showed Barrett's esophagus but no visible cancer had four-quadrant esophageal biopsies taken every 2 cm. After resection for high-grade dysplasia or early adenocarcinoma, the esophagus was mapped histologically. RESULTS: Nineteen patients had surgery for high-grade dysplasia; two of them (10.5%) had adenocarcinoma in the resected esophagus. Eleven patients had resection after a biopsy diagnosis of adenocarcinoma or suspicion of adenocarcinoma. Esophagectomy mapping confirmed carcinoma in only five of them. Median surface areas were: total Barrett's esophagus 32 sq cm, low-grade dysplasia 13 sq cm, high-grade dysplasia 1.3 sq cm, adenocarcinoma (seven cases) 1.1 sq cm. CONCLUSIONS: Areas of high-grade dysplasia and microscopic carcinoma in Barrett's esophagus are often small. Biopsy differentiation between these lesions is difficult. A systematic endoscopic biopsy protocol will reduce the chance of missing early malignancy in Barrett's esophagus.     

Is prophylactic treatment after myocardial infarction evidence-based?

In Barrett's esophagus, the squamous lining of the lower esophagus is replaced by columnar epithelium. Barrett's esophagus is associated with gastroesophageal reflux and an increased risk of the development of esophageal cancer. Endoscopy shows red columnar epithelium in the lower esophagus. Biopsy is needed to confirm intestinal metaplasia. Some cases progress from dysplasia to invasive adenocarcinoma. Medical or surgical antireflux treatment controls symptoms and esophagitis, but Barrett's esophagus remains. Patients are usually followed up by endoscopy for detection of dysplasia or early cancer. For patients with low-grade dysplasia, follow-up is adequate; however, for those with high-grade dysplasia, esophagectomy or experimental endoscopic mucosal ablation is advised.     

Advances in the treatment of esophageal carcinoma

Recent changes in the epidemiology of esophageal carcinoma now recognize adenocarcinoma as the predominant histologic cell type. Barrett's esophagus and dysplasia in this epithelium identify patients who are at risk of developing invasive adenocarcinoma. This neoplasm is not a single entity with a consistently poor prognosis, and disease stage is important for determining therapy. These findings offer the potential for further development of therapeutic regimens. Endoscopic esophageal ultrasound is an accurate and reproducible staging tool. It allows the physician to determine clinical stage and modify treatment. T2 N0 M0 or lesser stage tumors have acceptable surgical cure rates, and patients should undergo immediate resection. Patients with more advanced T3 or N1 tumors have a potential for cure but do poorly with surgery alone. These patients should be considered for multimodality therapy. Palliative therapy should be given to patients with hematogenous metastatic disease. Treatment stratification by stage proves that esophageal carcinoma is not a uniformly fatal disease without hope for cure.     

Comparative bioavailability of two immediate release tablets of cisapride in healthy volunteers

Irradiation of B16 pigmented melanoma subcutaneously transplanted in C57 mice with a single 650 mJ pulse (10 ns) of 1064 nm light from a Q-switched Nd: YAG laser caused instantaneous bleaching of the pigmented tissue. Visual and histological examination of the resulting gray-colored tumor revealed the breakdown of melanosomes with no detectable alteration of the normal and tumor-overlying skin. Histological examination of the irradiated tumor showed some degree of vascular damage; the depth of the photodamage was not affected by the successive delivery of three consecutive light pulses. The bleached tumor grew at a modestly slower rate but the high-peak-power (HPP) laser treatment did not affect the tumor concentration of a photodynamic sensitizer Si(i.v.)-naphthalocyanine (isoBO-SiNc) intravenously injected 24 h before Nd:YAG irradiation. Treatment of the B16 pigmented melanoma by photodynamic therapy (PDT: 1 mg/kg isoBO-SiNc, 300 mW/cm2, 520 J/cm2) from a 774 nm diode laser immediately after the 1064 nm irradiation resulted in a 16 day delay of tumor regrowth, which was markedly longer than the delay (ca 6 days) obtained after PDT under identical conditions without the preirradiation. Thus, pretreatment of pigmented tumors with HPP 1064 nm light appears to enhance their susceptibility to conventional PDT. The tumor response was further enhanced by repeating the combined HPP/PDT treatment at an interval of 10 days (regrowth delay: 27 days), as well as by applying hyperthermia immediately after HPP/PDT (regrowth delay: ca 34 days).     

TWIST gene mutation in a patient with radial aplasia and craniosynostosis: further evidence for heterogeneity of Baller-Gerold syndrome

BACKGROUND: The optimal management of high-grade dysplasia in patients with Barrett's esophagus is controversial. The aim of this study was to assess the prevalence of unsuspected carcinoma at esophagectomy in patients with Barrett's esophagus with high-grade dysplasia after endoscopic surveillance with jumbo biopsy forceps compared with standard biopsy forceps. METHODS: Twelve patients with high-grade dysplasia in Barrett's esophagus without gross or microscopic evidence of carcinoma underwent esophagectomy after preoperative endoscopy with 4-quadrant jumbo biopsies at 2-cm intervals. The findings in this group were compared with those in a group of patients with Barrett's esophagus who underwent esophagectomy for high-grade dysplasia after biopsies obtained at 2-cm intervals with standard biopsy forceps. RESULTS: Unsuspected cancer was found in 4 of 12 (33%) patients in the jumbo biopsy group compared with 6 of 16 (38%) in the standard biopsy group (p = NS). All 6 cancers in the standard biopsy group were intramucosal, whereas 2 were intramucosal and 2 were submucosal in the jumbo biopsy group. No patients in either group had lymph node metastases. CONCLUSIONS: Unsuspected cancer is found frequently in patients with Barrett's esophagus who are undergoing esophagectomy for high-grade dysplasia despite the use of a rigorous jumbo biopsy protocol. Esophageal resection is still indicated in appropriately selected patients with high-grade dysplasia until better markers of cancer risk are available.     

Current problems with intrahepatic bile duct stones in Japan--congenital biliary malformations as a cause

BACKGROUND/AIMS: In patients with primary intrahepatic bile duct stones, strictures of the biliary duct are often present, but the relationship between these strictures and the formation of the stones remains controversial. Intrahepatic bile duct carcinoma in association with intrahepatic bile duct stones has recently been reported. The present study attempted to ascertain whether bile stasis induced by congenital biliary strictures is the basis for the formation of stones and occurrence of carcinoma. MATERIALS AND METHODS: We analyzed the location of strictures in 58 patients with strictures in the upper portion of the biliary tract including 38 patients with intrahepatic bile duct stones and 9 with intrahepatic bile duct carcinoma. The cell cycle of epithelial cells from the intrahepatic bile duct were analyzed with using proliferating cell nuclear antigen, which is a immunohistochemical staining method. RESULTS: Fifty six of 58 patients had congenital cystic dilatation of the common bile duct (two infant type and 54 adult type). Thirty eight patients had intrahepatic bile duct stones proximal to the strictures at the hepatic hilum. The location of the strictures were classified into four types. Nine patients had intrahepatic bile duct carcinoma and eight of the 9 carcinomas coexisted with intrahepatic bile duct stones. In the nine patients with intrahepatic bile duct carcinoma, the expression of proliferating cellular nuclear antigen (PCNA) in the carcinoma and the normal bile duct epithelium adjacent to the carcinoma was higher than that of patients with hepatocellular carcinoma without anomaly of the biliary duct. CONCLUSION: Considering the location of the strictures and clinical features, the strictures may have been formed congenitally. Furthermore, adult type cysts of the common bile duct with strictures in the upper portion of the biliary tract are thought to be the basis for the formation of primary intrahepatic bile duct stones. The most appropriate treatment for intrahepatic bile duct stones is thus suggested to be removal of the affected hepatic segment including the region of strictures, combined eventually with hepaticoenterostomy.     

Human microsporidiosis in the acquired immunodeficiency syndrome

BACKGROUND AND OBJECTIVE: Photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) for sensitization is a promising treatment for carcinoma in situ and diffuse premalignant changes of the bladder. We studied the biodistribution of PpIX in a range of tissues with oral and intravesical routes of administration of ALA and compared the photodynamic effects on bladder and skin. STUDY DESIGN/MATERIALS AND METHODS: Normal Wistar rats were given oral or intravesical ALA and PpIX levels in the liver, kidney, skin, and bladder measured by fluorescence microscopy on tissue sections. At the time of maximum PpIX levels, the bladder and skin on the back were illuminated with light at 630 nm and the PDT effects compared. RESULTS: PpIX fluorescence in the urothelium after 200 mg/kg given intravesically was comparable to that found after 100 mg/kg orally. The ratio of PpIX levels between the urothelium and the underlying muscle was the same for both routes of administration, although there appeared to be more selectivity of urothelial PDT necrosis after intravesical administration. Skin photosensitization was greater after oral ALA, the epidermal PpIX level being three times higher than after intravesical administration for comparable urothelial levels and the PDT effect being more marked. CONCLUSIONS: Intravesical instillation is preferable to oral administration of ALA for PDT ablation of the urothelium of the rat bladder without damage to the underlying tissue layers and for minimizing skin photosensitivity. The technique is now ready for clinical trials.     

Comparison between Er:YAG laser and conventional technique for root caries treatment in vitro

Effective ablation of dental hard tissues by means of the erbium-doped:yttrium-aluminum garnet (Er:YAG) laser has been reported recently, and its application to caries removal and cavity preparation has been expected. However, few studies have investigated the capability of the Er:YAG laser to treat caries. In the present study, the effectiveness of caries removal by using an Er:YAG laser in vitro was compared with that of conventional mechanical treatment. Thirty-one extracted human teeth with root caries were used. Half of the caries in each tooth was treated with the Er:YAG laser, and the other was removed with a conventional bur or was left untreated as a control. Laser treatment was performed by means of a combination of contact and non-contact irradiation modes with cooling water spray, with a new fiber delivery and contact probe system. Conventional bur treatment was conducted by means of a low-speed micromotor. Measurements of the time required for caries removal, histopathological observations of decalcified serial sections, scanning electron microscope (SEM) observations, and hardness measurements of the treated cavity-floor dentin were performed for each treatment. Due to the careful irradiation technique, a longer treatment time was required for the complete removal of carious dentin by the Er:YAG laser. However, the Er:YAG laser ablated carious dentin effectively with minimal thermal damage to the surrounding intact dentin, and removed infected and softened carious dentin to the same degree as the bur treatment. In addition, a lower degree of vibration was noted with the Er:YAG laser treatment. The SEM examination revealed characteristic micro-irregularities of the lased dentin surface. Our results show that the Er:YAG laser system is promising as a new technical modality for caries treatment.     

Glucagon-like peptide-2 inhibits centrally induced antral motility in pigs

BACKGROUND: Many individuals develop telangiectases on the face as they mature. The causative factors are numerous. Telangiectases are cosmetically concerning for many of those who are affected. Because of the ability to selectively target vessels, lasers have recently become the focus for treating small facial telangiectases. OBJECTIVE: The purpose of this study was to evaluate the efficacy of the diode-pumped frequency-doubled Q-switched neodymium: ytterium-aluminum-garnet (FD QSNd:YAG) laser (532 nm) for the treatment of telangiectases on the face. METHODS: The diode-pumped FD QSNd:YAG laser (532 nm, 400-micron spot size, 24-msec pulse train) was used to treat telangiectases on the face of 30 adult subjects. Patients were treated once, and clinical improvement and potential adverse effects were assessed at 4 and 8 weeks after treatment. RESULTS: One session of diode-pumped FD QSNd:YAG laser treatment either improved or totally cleared all treated facial telangiectases. CONCLUSION: The diode-pumped FD QSNd:YAG laser is effective for treating small facial telangiectases. An advantage of this laser is that it does not produce postoperative purpura.     

Adenocarcinoma arising in Barrett's oesophagus: evidence for the participation of p53 dysfunction in the dysplasia/carcinoma sequence

Adenocarcinoma arising in Barrett's oesophagus is often preceded by mucosal dysplasia, but little is currently known about the aetiology or natural history of this dysplasia/carcinoma sequence. To investigate the participation of the tumour suppressor gene p53 in this sequence, an immunohistochemical analysis of p53 protein overexpression, which is known to closely correlate with point mutation of the p53 gene, was conducted in 30 patients with Barrett's adenocarcinoma. Adjacent Barrett's mucosa was dysplastic in 21 (70%) patients. Sixteen (53%) tumours overexpressed p53, 10 of which had adjacent dysplastic Barrett's mucosa. In all 10 patients, this dysplastic mucosa also overexpressed p53, predominantly in areas of high grade compared with low grade dysplasia. In contrast, none of the dysplastic mucosa adjacent to 11 tumours lacking p53 overexpression showed detectable values of p53. These results suggest that p53 dysfunction may participate in the progression from dysplasia to carcinoma in some patients with Barrett's oesophagus.     

Treatment of peri-ocular skin lesions with the erbium:YAG laser

INTRODUCTION: A great number of consmetically disturbing, cutaneous lesions are localized in the periocular region. While various approaches for treatment such as excision, electrocauterization or cryosurgery often show unsatisfactory results, the use of laser technology is of increasing interest. MATERIAL AND METHODS: A total of 104 patients with different cutaneous periorbital lesions (wrinkles, xanthelasma, syringoma) were treated with a new erbium: YAG laser system (wavelength 2940 nm, pulse duration 0.350 ms and pulse energy 0.1-1.7 Joules), which works on the principle of vaporization. RESULTS: The erbium: YAG laser allows athermic ablation of very thin skin layers without scarring and with minimal lateral thermal injury due an extremely short pulse duration. Periorbital lesions can be treated effectively by erbium: YAG laser, and good to excellent cosmetic results can be obtained. CONCLUSIONS: The use of pulsed erbium: YAG laser is an effective and promising new method for treatment of different superficial periorbital cutaneous lesions.     

Nd:YAG laser therapy of recurrent epistaxis in hereditary hemorrhagic telangiectasia

BACKGROUND: Epistaxis is the leading symptom of hereditary hemorrhagic teleangiectasia (HHT). Over the last years several laser systems have been used for therapy. Only a few studies have published results of Nd:YAG laser therapy evaluating a larger number of patients. PATIENTS AND METHODS: From 1987 through 1996, forty-one patients with HHT were treated with a Nd:YAG laser due to recurrent epistaxis at the Department of Otorhinolaryngology of Kiel University. Thirty-two patients were followed-up over a period of at least 24 months. A centripetal technique was used for endonasal laser light application (15-25 Watts; 0.1-0.5 s), i.e., the laser light was applied from the periphery towards the center of the angiodysplasia. Intensive preoperative and postoperative nasal care with ointments was performed. RESULTS: Bleeding frequency and intensity decreased in 30 (94%) patients. Duration of the therapeutical success differed individually and varied from seven weeks to 14 months. Repeated laser therapy was necessary in 27 of 32 patients. CONCLUSION: The Nd:YAG laser is a suitable tool in the treatment of epistaxis in HHT. This procedure is less traumatic, less painful, and can be repeated multiple times. Nd:YAG laser therapy and other therapeutic options cannot obtain a lasting cure of Rendu-Osler-Weber syndrome. However, in the vast majority of cases recurrent nasal bleeding as the dominant symptom can be reduced in frequency as well as in intensity.     

bcl-2 protein expression in the Barrett's metaplasia-dysplasia-carcinoma sequence

The bcl-2 proto-oncogene encodes a protein that blocks programmed cell death (apoptosis). Although bcl-2 has been shown to be involved in the development of follicular lymphoma via a chromosomal translocation t(14;18), little is known about its function in non-hematolymphoid neoplasms. The bcl-2 protein is normally expressed in the regenerative crypt compartment of the colon, small intestine, and stomach, and has been found to be abnormally overexpressed as an early event in the dysplasia-carcinoma sequences of both ulcerative colitis-related and gastric neoplasias. This study was undertaken to evaluate the role of bcl-2 in the Barrett's metaplasia-dysplasia-carcinoma sequence. Thirty-six esophageal resection specimens were studied, using a monoclonal antibody to the bcl-2 protein on fixed paraffin-embedded specimens. Barrett's mucosa was present in each specimen: low-grade dysplasia in 35, high-grade dysplasia in 34, intramucosal carcinoma (IMC) in 23, and submucosal carcinoma in 13. In addition, a section of the gastric resection margin was evaluated for bcl-2 immunoreactivity in each case. In all cases, the regenerative compartment of the gastric mucosa in the resection margins stained for bcl-2; however, no immunoreactivity was seen in any of the cases of Barrett's mucosa with or without dysplasia or carcinoma. We conclude that, in contrast to its role in gastric neoplasia, bcl-2 alterations are not an important molecular marker in the neoplastic progression of Barrett's mucosa.     

Endoscopic Nd:YAG laser treatment of inoperable lower gastrointestinal cancer

Many patients with colorectal cancer are not amenable to curative resection at the time of presentation. Nevertheless, palliative resection still remains as the treatment of choice in the majority of patients. A small group of patients that are poor candidates for surgical resection may benefit from some non-surgical palliative procedures to relieve their symptoms. Electrocoagulation, cryosurgery and radiotherapy are some of the non-surgical procedure used and they are associated with high morbidity and mortality. The use of Neodymium: Yttrium-Aluminium-Garnet (Nd:YAG) laser photoablation to palliate patients with advanced colorectal carcinoma is well documented. It is associated with relatively low morbidity and perioperative mortality. It requires no anaesthesia and is the only non-surgical procedure that can be safely carried out above the peritoneal reflection. Nd:YAG laser had been used in some centres as a preresectional procedure in patient presenting with high grade obstruction. It allows proper bowel preparation followed by primary excision and anastomosis. As a palliative procedure, most patients showed rapid improvement in obstructive symptoms, bleeding and rectal discharge. The size of the lesion and circumferential extent of the tumour base correlate well with the response rate. Most patients remained asymptomatic before they succumb to the advanced disease. In our series, good palliation of obstructive symptoms was achieved in all obstructive cases with one laser treatment, bleeding tumours required an average of two sessions for complete haemostasis. In conclusion, Nd:YAG laser therapy is a safe and efficacious means for palliation of obstructive symptoms and bleeding in advanced rectal carcinoma.     

Absence of human papillomavirus DNA in the plume of erbium:YAG laser-treated warts

BACKGROUND: The erbium:YAG laser (Continuum Biomedical, Dublin, Calif.) is a new resurfacing and ablating laser that produces minimal residual thermal damage. Laser safety requires careful attention to the hazards of the laser plume. It is important to know whether viable organisms survive in the vapors. Human papillomavirus (HPV) DNA has been detected in the vapor of carbon dioxide laser-treated and electrodesiccated human warts. The presence or absence of HPV DNA in the laser plume of erbium:YAG laser-treated warts has not been previously studied to our knowledge. OBJECTIVE: Our purpose was to determine the presence or absence of HPV DNA in the laser plume of erbium:YAG laser-treated human warts. METHODS: One half of clinically typical and histopathologically confirmed verrucae vulgares from five patients were submitted for HPV DNA detection with in situ hybridization. After erbium:YAG laser ablation of the remainder of the warts, the laser plume was deposited on the handpiece as an abundant fluffy material and was submitted for evaluation of HPV DNA by polymerase chain reaction with consensus primers for the HPV type detected in the wart specimens. RESULTS: HPV2 DNA was found in all warts. HPV DNA was not detected in the erbium:YAG laser plume after ablation of these same warts. CONCLUSION: The absence of HPV DNA in the plume of erbium:YAG laser-treated warts is a significant safety feature of this laser.