Michel Prudhomme

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.

Applications and mechanisms of laser tissue welding in 1995: review

For several years laser tissue welding has appeared as a new alternative technique for tissue repair instead of manual sutures. It has been evaluated in different experimental models including blood vessels, skin, nerve, intestine, bile ducts, vas and fallopian tube. Different types of lasers with different sets of parameters have been used: carbon dioxide laser, Nd:YAG laser, argon and KTP laser and diode laser. Recent trends in tissue fusion promote near infrared lasers at low irradiance with intraoperative enhancement of light absorption by specific chromophores. As far as microvascular reconstruction is concerned, successful clinical applications are currently published. Although the molecular mechanism involved in welding is not completely understood, the tissular fusion is considered as a thermal phenomena. In laser assisted microvascular anastomosis, the best experimental model, the ultrastructural examination of arteries anastomosed with Nd:YAG, argon or diode laser revealed interdigitation of collagen fibers which appeared swollen, with modified striation and organized in irregular network. The mechanism of welding involving the formation of non covalent bands between collagen strands, is generally induced by a temperature of 60 - 63 degrees Celsius well adapted to collagen denaturation.

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.

Infectious complications, prognostic factors and assessment of anti-infectious management of 212 consecutive patients with acute pancreatitis

AIM Acute pancreatitis is an important cause of morbidity and mortality, mainly due to sepsis. The aim of this study was to determine the incidence of infectious complications and their impact on mortality in patients hospitalized for acute pancreatitis. PATIENTS AND METHODS Patients admitted for acute pancreatitis were retrospectively included within a period between 1995 and 2000. Incidence of abdominal and extra-abdominal sepsis and specific care were specifically analyzed. Risk factors for death were evaluated by uni- and multivariated analysis. RESULTS Two hundreds and twelve consecutive patients (128 males, median age 54 years) were included. Mortality was 10.8%. At least one infectious episode was collected in 25% of the patients with an abdominal sepsis (26.8%), bacteriemia (24.4%), respiratory (24.4%) and urinary tracts (19.5%) infections. Infection was polymicrobial in 37.5%. An antibiotic prophylaxis was administered in 10.8%, more often in patients with severe pancreatitis. It did not alter mortality or incidence of infections but significantly delayed occurrence of sepsis. Mortality of patients treated with more than one line of antibiotics was higher. However in this study infectious complications were not an independent factor for mortality. CONCLUSION Infections are frequent and polymicrobial but are not an independent prognostic factor during acute pancreatitis.

Perineal descent predicted by a pelvic bone factor: the pelvic incidence angle.

PURPOSE: By measuring the pelvic incidence angle, we assessed the relationship between pelvic floor disorders and pelvic morphology, which allowed us to document for the first time the hypothesis that pelvic incidence may be a predictive factor of perineal descent. METHODS: In a retrospective study of 197 women, the perineal descent at rest and during straining was assessed by defecography. The pelvic incidence angle (53° ± 9°, independent of the subject position) was defined as the angle between the line perpendicular to the sacral plate at its midpoint and the line connecting this point to the middle of the femoral heads axis. The pelvic incidence angle was correlated with the incidence of pelvic floor descent. RESULTS: In those with pelvic floor descent at rest compared with those without, pelvic incidence angle was significantly larger (64° vs. 53°, P < 10E-06). As a predictive factor of perineal descent at rest, a great pelvic incidence (>62°) had a sensitivity (73 percent), specificity (82 percent), positive predictive value (81 percent), and negative predictive value (75 percent). CONCLUSIONS: A large pelvic incidence (>62°) may be a predictive factor of perineal descent at rest before the apparition of other acquired factors. With pelvic incidence >62°, a large overhang between the insertions increases the strains on the perineum, which is rather horizontal.

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.

Syndrome de polysplénie : à propos de deux cas révélés chez l’adulte par des malformations biliaires et pancréatiques

Polysplenia Syndrome (PS) associates multiple spleens with other malformations usually cardiac, vascular, visceral and biliary. The diversity of these malformations and their embryological mechanisms are described in relation to two cases of PS that were diagnosed in adults.Resume Le syndrome de polysplenie (SP) associe chez un meme malade des rates multiples a d’autres malformations dont les plus frequentes sont : cardiaques ; vasculaires ; viscerales et biliaires. La diversite de ces malformations et leur explication embryologique sont decrites a partir de deux cas cliniques de SP diagnostiques a l’âge adulte.

Morphological study of the healing process after diode laser-assisted end-to-end microanastomosis: comparison with conventional manual suture

A series of carotid end-to-end diode laser assisted microvascular anastomosis (LAMA) versus control ateral conventional suture microanastomosis (CMA) were performed in 120 Wistar rats (in the same animal, LAMA performed in the left side and CMA in the right). The optic and scanning electron microscopic examinations were assessed from day 0 to day 210. The results revealed that on day 0 LAMA gave rise to proteins deneturation and collagens fusion of the media and adventitia in the arterial wall. Re-endothelialization of anastomotic line began at day 3, as well as a large number of inflammatory aggregated in the adventitia. On day 10 the endothelial cells were restored on the anastomotic site and collagenous network developed in the media. On day 90 proliferation and disorientation of the elastic fibers appeared. A part of elastic laminae had been reconstructed on day 210. In the group CMA, the re- endothelialization developed later than LAMA, and the reconstruction of the elastic laminae failed to happen until day 210. These data suggest that the results of long term healing process after diode LAMA is better than that of CMA in normal artery repair.

Microarterial anastomoses using the diode laser: long term morphological results

In a series of 70 Wistar rats submitted to a noncontact diode laser-assisted carotid end-to-end anastomosis (LAMA) versus controlateral manual suture microanastomosis (CMA), contrast angiography and scanning electron microscopy were performed in a group of 18 animals at a long-term follow up of 7 months after operation. The investigation of angiography realized by means of a CGR General Electric DG 200 with a 512 digital matrix gave precise images of vessel wall repair and vessel patency. It permitted a simultaneous comparison between laser and manual anastomosis. Patency rate was 83% in LAMA and 78% in CMA. Nonlethal complications such as 1 stenosis, 2 thromboses in LAMA and 1 stenosis, 2 thromboses, and 1 pseudoaneurysm in CMA were observed. The results could be correlated to scanning electron microscopy findings and confirmed the morphological superiority of the laser technique.

Laser tissue welding: a new device controlled by reflectance

Laser tissue welding is used to close wounds or to anastomose conducts such as arteries. The welding effect is due to tissue denaturation which depends on the irradiation parameters. An excessive laser irradiation leads to irreversible thermal damage. In conventional welding procedures, laser irradiation is controlled by visual inspection of the welded zone. A new device based on an 800 nm diode laser allowing an automated welding procedure is described here. The device measures the variation of the diffuse reflectance on the treatment area and stops laser irradiation when a given optimal value is reached. This allows the user to increase the reproducibility of the treatment by avoiding the subjective aspect of welding completion assessment by visual criteria. The system has been tested by in vitro welding an egg yolk membrane on mesenteric bovine arteries. The results have shown that for a given laser power, there is a specific reflectance decrease threshold value leading to an optimal welding. Reproducible welds with minimal thermal damage could be obtained.