G. Godlewski

Morphologic changes in collagen fibers After 830 nm diode laser welding

The mechanism of laser tissue welding is elusive, but collagen transitions are somehow involved. Collagen fiber modifications observed after 830 nm diode laser welding are presented in this study.

EMBRYOLOGY AND ANATOMY OF THE ANORECTUM: Basis of Surgery

The rectum is a pelvic organ, complex in its morphology and its topographic relationships. Its double embryologic origin explains the two types of tumors that develop in the rectum: (1) lieberkühnian adenocarcinoma in the pelvic rectum and (2) squamous epithelioma in the anal canal. Its venous and lymphatic supply, intensively developed, realizes early pathway of tumoral dissemination. The pelvic relationships of the rectum and anus explain the technical difficulty of rectal surgery, especially when subperitoneal resection and anastomosis are concerned. Imaging of this area permits an early diagnosis of rectal tumors and allows a less invasive surgery with a carcinologic precision.

Quantitative changes in collagen levels following 830-nm diode laser welding

The actual mechanism by which laser irradiation welds tissue is presently unknown; however, collagen is a major constituent of tissue welded by laser irradiation.

Interstitial diode laser hyperthermia in the treatment of subcutaneous tumor

Interstitial Laser Hyperthermia (ILH) has been investigated since the early 80s in the treatment of deep seated tumors. The purpose of this study was to evaluate the efficiency of diode ILH (830 nm) in a subcutaneous tumor model.

Biliary structures lead to tumour recurrences after laser‐induced interstitial thermotherapy

Thermal diffusion during laser‐induced interstitial thermotherapy (LITT) has not yet been fully investigated in heterogeneous tissue architecture such as liver. LITT was performed on rabbit liver tumours to analyse the role of biliary structures in thermal diffusion.

A new method of three-dimensional computer assisted reconstruction of the developing biliary tract.

A three-dimensional (3-D) computer assisted reconstruction of the biliary tract was performed in human and rat embryos at Carnegie stage 23 to describe and compare the biliary structures and to point out the anatomic relations between the structures of the hepatic pedicle. Light micrograph images from consecutive serial sagittal sections (diameter 7 mm) of one human and 16 rat embryos were directly digitalized with a CCD camera. The serial views were aligned automatically by software. The data were analysed following segmentation and thresholding, allowing automatic reconstruction. The main bile ducts ascended in the mesoderm of the hepatoduodenal ligament. The extrahepatic bile ducts: common bile duct (CD), cystic duct and gallbladder in the human, formed a compound system which could not be shown so clearly in histologic sections. The hepato-pancreatic ampulla was studied as visualised through the duodenum. The course of the CD was like a chicane. The gallbladder diameter and length were similar to those of the CD. Computer-assisted reconstruction permitted easy acquisition of the data by direct examination of the sections through the microscope. This method showed the relationships between the different structures of the hepatic pedicle and allowed estimation of the volume of the bile duct. These findings were not obvious in two-dimensional (2-D) views from histologic sections. Each embryonic stage could be rebuilt in 3-D, which could introduce the time as a fourth dimension, fundamental for the study of organogenesis.

Kyste vestigial rétrorectal de l'adulte

STUDY AIM: The aim of this retrospective study was to report three cases of retrorectal vestigial cyst in adults. PATIENTS AND METHOD: From 1977 to 1999 retrorectal vestigial cyst (RVC) was diagnosed in our department in three women who were 28, 57 and 53 years of age, respectively. RVC was revealed by either pain (n = 2) that occurred in one case in a pregnant woman, or acute intestinal obstruction (n = 1). The patients were operated on using a perineal approach in two cases and an abdominal approach in one case. RESULTS: One epidermoid cyst and two mixed cysts without any sign of malignancy were observed. Postoperative follow-up was simple in two patients, while complications occurred in the third one via an uretero-vaginal fistula which required uretero-vesical reimplantation. The first two patients, reviewed after a 1-year follow-up, had no functional trouble and no sign of recurrence. CONCLUSION: Retrorectal vestigial cysts are very rare tumors with a risk for degeneration. Computerized tomography on nuclear magnetic resonance and endorectal ultrasonography allow detection of their structure and topography and help guide their surgical approach. In the absence of malignancy, wide excision, if possible without opening of the cystic wall, leads to good results.

Diode laser and microvascular carotid anastomosis: A preliminary study

A crossed carotid end-to-end anastomosis was performed in 20 Wistar rats by means of a diode laser device (wavelength 830 nm and power output 3 W in continuous wave). The diode laser energy was delivered into a micromanipulator coupled to an OPMI 1 Zeiss operating microscope with a focused spot of 300 μm diameter. The vessel sealing was effected on common carotids (0.8–1.2 mm) using laser shots (average 9) of 680 mW power and 4.5 s duration and 962 W cm−2 irradiance each. The good vascular flow was confirmed by Doppler spectral analysis and angiography performed on days 0, 10 and 30. Light and scanning electron microscopy showed that reendothelialization was complete on day 10 whilst collagenous fusion of media and adventitia was obvious. The patency rate was 90% impaired by a lethal thrombosis. The efficiency of the diode laser was compared to that of other types of LAVA and to manual microanastomosis.

Liver Development in Rats during the Embryonic Period (Carnegie Stages 11–14)

The hepatic structures appearing during Carnegie stages 11-14 were analyzed in a series of 61 OFA rat embryos. The group of embryos (crown-rump length 2-7 mm, 10th-12th days after coitus) was composed of 52 specimens of the somite period (stages 11 and 12) and of 9 specimens of the postsomite period (stages 13 and 14). The embryos were submitted to serial histological sectioning with graphic reconstruction. Stage 11 was characterized by the development of the hepatic diverticulum induced by differential growth of the endodermal plate and fixed contact between the entoderm and endothelium lining the heart. Stage 12 presented obvious signs of cellular differentiation, the septum transversum giving the liver stroma and the hepatic diverticulum the epithelial trabecula. At stage 13 the epithelial cords enmeshed the stromal capillaries, while hepatocardiac veins drained the hepatic flow into the sinus venosus. Stage 14 was recognized by the presence and development of the hepatic lobes and the enlargement of vascular channels. The cystic bud was never observed. The identification of these features permits to precise the hepatic developmental staging in rats and to obtain accurate criteria for the characterization of the end of the somite period and the beginning of the postsomite period.

Prenatal Organization and Morphogenesis of the Sphenofrontal Suture in Humans

Objective: The aim of this study was to describe the prenatal structure and morphogenesis of the sphenofrontal suture. Methods: Eleven human specimens, two embryos and nine fetuses, were prepared for light microscopy study of the sphenofrontal suture. Ten-micrometer sections were made with the microtome in the sagittal plane from the midline to the sphenoidal fontanelle. Results: At the end of the fetal period, the sphenofrontal suture had a five-layer structure like the cranial sutures, and was formed by two different morphogenetic unities. The orbitosphenofrontal suture was formed between the membranous ossification of the orbital part of the frontal bone and the endochondral ossification of the lesser wing of the sphenoid bone, i.e. the ala orbitalis. In the early stage, a transient sphenoethmoidal cartilage was inserted between these two ossifications. The second unit, the lateral sphenofrontal suture, was formed between the frontal bone and the greater wing of the sphenoid, and the ossification was membranous in this portion. It is formed like the cranial suture, directly from the mesenchyme. Conclusion: The sphenofrontal suture is a typical fibrous suture arising from two morphogenetic unities.