In situ X-ray absorption spectroscopy study of Si(1-x)Ge(x)O2 dissolution and germanium aqueous speciation under hydrothermal conditions.

The dissolution of Si(1-x)Ge(x)O(2) solid solutions under hydrothermal conditions was studied by in situ X-ray absorption spectroscopy. Experiments were performed at the Ge K-edge using a high-pressure cell mounted on the FAME beamline of the European Synchrotron Radiation Facility. Spectra in both transmission and fluorescence mode were collected in isobaric conditions (100 and 150 MPa) up to 475 °C. The local atomic structure around the Ge atom was investigated as a function of the temperature and in pure water and sodium hydroxide solutions. In pure water, the solubility of the cristobalite-type Si(0.8)Ge(0.2)O(2) increases with the temperature and the Ge atom is in 4-fold coordination. In a sodium hydroxide aqueous solution, a complex between Ge and Na atoms forms and gives rise to precipitation of sodium germanates. Under these conditions, the Ge content in the solution decreases with increasing temperature. These results show that a sodium hydroxide aqueous solution, usually used for quartz crystal growth, is not suitable for Ge-containing crystals. The dissolution kinetics and phase transformation of the solid solution were studied as a function of the atomic fraction of Ge. Ge-rich solid solutions dissolve and transform to stable phases faster than Ge-poorer composition, giving rise to important variations of the Ge content in solution.

Sacral nerve stimulation for faecal incontinence: response rate, satisfaction and the value of preoperative investigation in patient selection.

OBJECTIVE: Before undergoing sacral nerve stimulation (SNS) for faecal incontinence (FI), patients are investigated with morphologic, dynamic and electrophysiologic tests. The purpose of our study was to evaluate their value in the selection of patients who may benefit most from neuromodulation. METHOD: If temporary stimulation resulted in a good objective response, a permanent neuromodulator was implanted. Patients were reviewed at 3 months and then at 6 monthly intervals. Asked by telephone, patient's satisfaction was described as good, satisfactory or poor. RESULTS: Forty-five consecutive patients (41 females, median age 59 years) with FI (Wexner 16.1 +/- 2.9) underwent SNS. Temporary stimulation was successful in 32 (71)% patients. At a median follow-up of 33 months, the neuromodulator remained in place in 25 (55%) patients, two do whom switched it off, leaving 23 (51%) with a functioning neuromodulator. There was no statistically significant difference between the characteristics (including manometry, ultrasound and electrophysiology) of patients undergoing implantation (n = 32) or not (n = 13) and those with or without a functioning stimulator (n = 23: n = 13). In the 23 patients with a functioning stimulator the result was good in 12, satisfactory in five and poor in six. There was no statistically significant difference in the patient characteristics between those with a good result (n = 12) and the remainder (n = 32). CONCLUSION: The findings suggest that investigation for FI does not facilitate patient selection for SNS and cannot be used to predict outcome.

Initial structure memory of pressure-induced changes in the phase-change memory alloy Ge2Sb2Te5.

We demonstrate that while the metastable face-centered cubic (fcc) phase of Ge2Sb2Te5 becomes amorphous under hydrostatic compression at about 15 GPa, the stable trigonal phase remains crystalline. Upon higher compression, a body-centered cubic phase is obtained in both cases around 30 GPa. Upon decompression, the amorphous phase is retained for the starting fcc phase while the initial structure is recovered for the starting trigonal phase. We argue that the presence of vacancies and associated subsequent large atomic displacements lead to nanoscale phase separation and loss of initial structure memory in the fcc staring phase of Ge2Sb2Te5.

In situ high pressure and high temperature Raman studies of (1-x)SiO(2)xGeO(2) glasses.

The structure of glasses in the binary system SiO(2)-GeO(2) has been studied by Raman spectroscopy. Our results are consistent with mixing of SiO(2) and GeO(2) tetrahedra. The changes induced by temperature and by pressure on the structure are monitored by in situ measurements on the same mixed glasses. Anomalous temperature dependences are observed not only for SiO(2) glass and GeO(2) glass but also for mixed glasses. Particular attention is focused on the pressure densification mechanism in mixed glasses. Via the pressure dependence of the width of the main Raman band, we show that the compression mechanism in mixed glasses is intermediate between that of the end members.

Risk factors for development of desmoid tumours in familial adenomatous polyposis.

BACKGROUND: Desmoid tumours (DTs) are the primary cause of death of patients with familial adenomatous polyposis (FAP) following restorative proctocolectomy. The aim of this study was to identify risk factors for DT in a French population. METHODS: Clinical data for 442 patients with FAP from 1983 to 2004 were reviewed retrospectively. RESULTS: A total of 124 DTs were documented in 50 patients (25 female). DT sites were mesenteric (73 tumours), abdominal wall (44) and extra-abdominal (seven). Female patients developed DT earlier than males. Although DTs appeared after colectomy in 34 patients, the type of surgery did not influence the risk of DT. An identified point mutation in the adenomatous polyposis coli (APC) gene after codon 1444 was a significant risk factor (hazard ratio 3.3 (95 per cent confidence interval 1.5 to 7.3)). Belonging to a family affected by DT did not increase the individual's risk in this population. CONCLUSION: No risk factor for life-threatening mesenteric DT could meaningfully modify the management of patients with FAP.

Radiofrequency ablation for recurrent pelvic cancer.

OBJECTIVE: Local recurrence of pelvic cancer is a therapeutic challenge. The purpose of the study was to evaluate radiofrequency ablation (RFA, intra-operative or CT-guided) for the treatment of pelvic recurrence in patients not eligible for curative surgical resection. METHOD: Charts of all patients treated for pelvic recurrence by RFA between March 2004 and March 2005 were reviewed. RESULTS: Eight patients (two females) had RFA for inoperable local recurrence [rectal adenocarcinoma (six) and sarcoma (two)]. Surgical resection of the primary tumour had been performed at a median age of 50.2 (36.7-61.6) years. Recurrence occurred after a median of 49.5 (11.7-63.5) months. The mean size of the recurrence was 33.4 (20-45) mm. RFA was given on a median number of two occasions (1-3). Complications occurred in six patients including minor pain [pelvic (six); sciatic nerve irritation (four)]; ureteric obstruction requiring stenting (two) and colo-vesical fistula (one), requiring ileal urinary diversion. After a median follow-up of 18.2 months (11-32), six patients were still alive. Patients, who had experienced pain prior to RFA were pain-free. Five patients showed evidence of further tumour growth but were asymptomatic. CONCLUSION: Radiofrequency ablation is a feasible therapeutic option for recurrent pelvic cancer. It allows good symptom control in patients with pain but morbidity is high.

Colorectal neoplasia in Crohn's colitis: a retrospective comparative study with ulcerative colitis.

AIMS: To determine the clinicopathological features of colorectal cancer (CRC) in Crohn's disease (CD). METHODS AND RESULTS: All histological slides from surgical specimens with inflammatory bowel disease-related colorectal neoplasia examined in our hospital between 1990 and 2005 were reviewed. We identified 18 CRCs in 16 patients with CD and compared them with 57 CRCs in 41 patients with ulcerative colitis (UC). We also studied 25 patients with dysplasia without cancer (CD 2, UC 23). When CD and UC were compared, the median age at diagnosis of cancer (CD 52 years, UC 51 years), the frequency of mucinous adenocarcinoma (CD 16.7%, UC 17.5%) and the frequency of dysplasia adjacent to and distal from cancer (CD 56.3 and 37.5%, UC 65.8 and 39%, respectively) were similar. All neoplastic lesions occurred in areas affected by inflammatory bowel disease. CONCLUSIONS: CRC complicating CD and UC shares many clinicopathological features, in particular similar frequencies of dysplasia, both adjacent and distal, with cancer. Thus, surveillance for patients with Crohn's colitis should be similar to that for patients with UC. Consideration should be given to a more extensive UC-like surgical approach instead of segmental resection of the involved area.

[Epidermoid carcinomas of anal canal treated with radiation therapy and concomitant chemotherapy (5-fluorouracil and cisplatin)]. / Carcinomes épidermoïdes du canal anal traités par association concomitante de radiothérapie et de chimiothérapie. Evaluation des résultats fonctionnels.

PURPOSE: To evaluate our results after radiation therapy and concomitant chemotherapy in terms of local control, survival and toxicity in patients with anal cancer. METHODS AND PATIENTS: Between November 1990 and January 2002, 60 patients (pts) were treated with radiation therapy and concomitant chemotherapy. The T-stage according to the 2001 UICC classification were: 2 T1, 26 T2, 25 T3, and 7 T4. There were 20 pts with nodal involvement at presentation. The treatment started with external beam RT (median dose: 45 Gy) and concomitant chemotherapy using 5-fluorouracil and cisplatin during the first week and the fifth week of external beam RT (EBRT). After a rest period of 4 to 6 weeks, a boost of 20 Gy was delivered by EBRT in 58 pts and by interstitial (192)Ir brachytherapy in 2 pts. Mean follow-up were 78.5 months. RESULTS: At the end of RT with concomitant chemotherapy local tumor clinical complete response rate was 83%. Out of 10 non responders or local progression, 5 (50%) were salvaged with abdominoperineal resection (APR). Out of 5 local tumor relapses, 3 were salvaged with APR. The overall local tumor control (LC) rate with or without salvage local treatment were 88%. LC rate with a good anal function scoring (score 0 and 1) was 70%. Among 43 pts who preserved their anus, 98% had a good anal function scoring. The 5-year disease-free survival was 75%. After multivariate analysis, 2 independent predicting factors significantly influenced the disease-free survival: HIV-positive pts (negative vs positive, P=0.032) and clinical tumor response after the first course of radiotherapy (<50% vs >or=50%, P=0.00032). Acute grade 2 or 3 toxicities were low: haematological toxicity in 4 pts and intestinal complication corresponding to diarrhea in 10 pts. Late severe complication was observed in 3 pts: 2 pts with painful necrosis of the anus requiring colostomy and 1 pt with grade 3 rectal bleeding. CONCLUSION: We confirm the good results with RT and concomitant chemotherapy. The clinical tumor response after the first course of RT and concomitant chemotherapy is probably the most important predictive factor on the disease-free survival. For patients with T3 or T4 lesion and tumor regression

Outcome of antegrade continence enema procedures for faecal incontinence in adults.

BACKGROUND: Faecal incontinence has major consequences. Colostomy has been the mainstay of therapy when other options fail. Operations such as the Malone procedure have been proposed as an alternative. The aim of this study was to evaluate the outcomes and quality of life of patients having a Malone procedure for the treatment of faecal incontinence. METHODS: Charts of patients who had had a Malone procedure or equivalent between 1998 and 2004 were reviewed. The patients completed a Short Form (SF) 36 quality of life questionnaire. RESULTS: The study included 25 patients (17 female; median age 47 years). In seven, the appendix was used; an ileoneoappendicostomy was performed in the other 18. Three patients were lost to follow-up; the remaining 22 were followed for a median (range) of 21 (1-61) months. Five patients had a cutaneous stenosis; another had the appendicostomy removed and replaced by a colostomy. Four patients no longer used the stoma for irrigation. All other patients were completely clean except one, who reported occasional night-time seepage. The mean SF-36 showed a good physical recovery (43.9) but persisting psychological distress (36.0). CONCLUSION: The Malone procedure or equivalent achieves good results in the management of faecal incontinence, although psychological distress persists after surgery.

Causes and outcomes of pouch excision after restorative proctocolectomy.

BACKGROUND: Pouch failure occurs in up to 10 per cent of patients after ileal pouch-anal anastomosis (IPAA). The aims of this study were to determine the reasons for pouch excision and to evaluate the outcome of the perineal wound after pouch excision. METHODS: Between 1984 and 2002, 91 patients with severe ileal pouch dysfunction were treated. This was a retrospective analysis of data collected prospectively from 24 patients who underwent pouch excision. RESULTS: Patients were grouped according to the final histological diagnosis. Fourteen patients with Crohn's disease developed extensive fistulous disease and/or recurrent abscesses, of whom six had a persistent perineal sinus after pouch excision. Five patients had familial adenomatous polyposis, in three of whom desmoid tumours were the cause of failure. Three patients had chronic ulcerative colitis and developed recurrent pelvic sepsis. Finally, two patients with multiple colorectal adenocarcinoma developed recurrent cancer (one) or sepsis (one). CONCLUSION: Sepsis was the principal reason for pouch excision and was usually associated with recrudescent Crohn's disease in the pouch. Perineal wound healing was problematic after pouch excision for Crohn's disease.

A high-temperature Raman scattering study of the phase transitions in GaPO(4) and in the AlPO(4)-GaPO(4) system.

Al(1-x)Ga(x)PO(4) solid solutions (x = 0.2, 0.3, 0.38, 0.7) and the pure AlPO(4) (x = 0) and GaPO(4) (x = 1) end members with the α-quartz-type structure were studied by Raman scattering. An investigation as a function of composition enabled the various modes to be assigned, in particular coupled and decoupled vibrations. The tetrahedral tilting modes, which have been linked to high-temperature phase transitions to ß-quartz-type forms, were found to be decoupled. In addition, it is shown that Raman spectroscopy is a powerful technique for determining the gallium content of these solid solutions. Single crystals with x = 0.2, 0.38, and 1.0 (GaPO(4)) were investigated at high temperature. The composition Al(0.8)Ga(0.2)PO(4) was found to exhibit sequential transitions upon heating to the ß-quartz and ß-cristobalite forms at close to 993 K and 1073 K, respectively. Direct α-quartz-ß-cristobalite transitions were observed for the two other compositions at close to 1083 K and 1253 K, respectively, upon heating. The spectra of the ß-quartz and ß-cristobalite forms indicate the presence of significant disorder. Back transformation to the α-quartz-type form occurred readily with a hysteresis of less than 100 K for the composition x = 0.38 and for pure GaPO(4). Rapid cooling was necessary to obtain the metastable α-cristobalite form. In contrast, for Al(0.80)Ga(0.20)PO(4), the α-cristobalite form was obtained even upon slow cooling.

Influence of fictive temperature and composition of silica glass on anomalous elastic behaviour.

In order to determine the influence of the thermal history (fictive temperature) and OH content on the elastic properties of silica glass, we have investigated high resolution in situ Brillouin experiments on SiO(2) glass from room temperature to the supercooled liquid at 1773 K across the glass transition. The well known anomalous increase of elastic modulus in the glassy state and in the supercooled liquid regime is observed. No change in the slope of the elastic moduli of silica appears as a characteristic of the glass transition, in contrast to what happens in various other glasses. We show that thermal history has a weak effect on elastic moduli in the glass transition regime for silica glass. The effect of the water content in silica glass is greater than the fictive temperature effect and gives larger changes in the amplitude of the elastic modulus for the same thermal dependence. A singular decrease above 1223 K is also observed in the shear moduli for hydrated samples. Different models explaining the temperature dependence of the elastic properties in relationship with frozen-in density fluctuations or with the structure are discussed.

Complete rectal prolapse in young patients: psychiatric disease a risk factor of poor outcome.

OBJECTIVE: Complete rectal prolapse is rare before the age of 50. The aim of our study was to identify the risk factors of total rectal prolapse before this age and to determine the surgical outcome in this specific group of patients. PATIENTS AND METHODS: The charts of all patients, younger than 50 years old, treated for total rectal prolapse between June 1995 and December 2001 were reviewed. Associated conditions were noted and pre and postoperative functions were compared in regards of constipation and evacuations problems, anal continence (Wexner score), recurrent prolapse and overall satisfaction. All patients underwent an abdominal rectopexy according to the Orr-Loygue procedure. RESULTS: During the study period, 28 patients (21 females) with a mean age of 34 +/- 9 years were treated for a total rectal prolapse in our institution. Five patient (17.8%) had minor complications. After a mean follow up of 25 months, the global continence improved significantly (Wexner score: 4.9 vs 2; P = 0.014): 8 patients suffering from liquid stools incontinence before surgery were continent after rectopexy, while 2 continent patients became incontinent to liquid stools after surgery. Fourteen patients had chronic psychiatric disease requiring permanent treatment. These patients suffered more frequently from constipation (12/14 vs 5/14; P =0.006) and required more often a digital evacuation before surgery (6/14 vs 1/14; P = 0.07) than non psychiatric patients. They also suffered from more severe constipation and required more enemas after surgery (1/14 vs 6/12; P = 0.03) compared to patients without psychiatric disease. The only two patients, who had recurrence also had psychiatric disease. CONCLUSION: Chronic psychiatric disease requiring long-term medication is observed in 50% of patients with total rectal prolapse under the age of 50 years. Moreover, the medically induced constipation in these patients could represent a cause of poorer functional outcome. Therefore, we recommend the identification of this preoperative risk factor to assess the results of total rectal prolapse treatment in patients younger than 50 years of age.

Salvage reoperation for complications after ileal pouch-anal anastomosis.

BACKGROUND: Surgical revision may be possible in patients with a poor outcome following ileal pouch-anal anastomosis (IPAA), using either a transanal approach or a combined abdominoperineal approach with pouch revision and reanastomosis. METHODS: Sixty-four patients underwent revisional surgery. The indication for salvage was sepsis in 47 patients, mechanical dysfunction in ten, isolated complications of the residual glandular epithelial cuff in three and previous intraoperative difficulties in four patients. RESULTS: A transanal approach was used in 19 patients and a combined abdominoperineal procedure in 45. Six of the latter had pouch enlargement and 25 received a new pouch. During a mean(s.d.) follow-up of 30(25) months, three patients required pouch excision because of Crohn's disease. Two patients had poor continence after abdominoperineal surgery. At last follow-up 60 (94 per cent) of 64 patients had a functional pouch. Half of the patients experienced some degree of daytime and night-time incontinence, but it was frequent in only 15 per cent. Of 58 patients analysed, 27 of 40 who had an abdominoperineal procedure and 13 of 18 who had transanal surgery rated their satisfaction with the outcome as good to excellent. CONCLUSION: Surgical revision after failure of IPAA was possible in most patients, yielding an acceptable level of bowel function in two-thirds of patients.

Primary rectus abdominis myocutaneous flap for repair of perineal and vaginal defects after extended abdominoperineal resection.

BACKGROUND: Significant morbidity can result from perineal wounds, particularly after radiotherapy and extensive resection for cancer. Myocutaneous flaps have been used to improve healing. The purpose of this study was to evaluate the morbidity and results of primary rectus abdominis myocutaneous flap reconstruction of the vagina and perineum after extended abdominoperineal resection. METHODS: Thirty-one consecutive patients undergoing one-stage rectus abdominis myocutaneous flap reconstruction of extensive perineal wounds were studied prospectively. Twenty-six patients had surgery for recurrent or persistent epidermoid anal cancer or low rectal cancer, and 21 had high-dose preoperative radiotherapy. RESULTS: Three weeks after the operation, complete healing of the perineal wound was seen in 27 of the 31 patients. There were nine flap-related complications including three patients with partial flap necrosis, two with vaginal stenosis, one with vaginal scarring, one with small flap disunion and two with weakness of the anterior abdominal wall. There were no unhealed wounds at the completion of follow-up (median 9 months). CONCLUSION: The transpelvic rectus abdominis myocutaneous flap for the reconstruction of large perineal and vaginal wounds achieves wound healing with only moderate morbidity in the majority of patients after extensive abdominoperineal resection with or without radiotherapy.

Sutured perineal omentoplasty after abdominoperineal resection for adenocarcinoma of the lower rectum.

PURPOSE: This study was designed to describe and evaluate the efficacy of sutured perineal omentoplasty on perineal wound healing after abdominoperineal resection for adenocarcinoma of the lower rectum. METHODS: Charts of patients who underwent abdominoperineal resection for adenocarcinoma of the rectum from June 1995 to December 2001 were reviewed for mortality, morbidity, and perineal healing. Abdominoperineal resection was accomplished according to Miles combined with total mesorectal excision. The omentum was pediculized on the left gastroepiploic artery and tightly sewn to the subcutaneous fatty tissue. The perineal skin was then closed primarily. RESULTS: A total of 104 patients were included in the study. The mean age at surgery was 65 (range, 13-91) years. The distance of the tumor from the anal sphincters was 0.45 +/- 0.9 mm (range, 0-50). During the study period, 92 patients (88 percent) had sutured perineal omentoplasty. The rate of primary perineal wound healing was 80 percent. Postoperative perineal wound complications consisted of perineal abscess in seven patients. Six of these patients had a sutured perineal omentoplasty (6 percent). Only four patients required a surgical drainage. Minor perineal suppuration occurred in four patients (4 percent), whereas partial perineal wound dehiscence occurred in eight patients (8 percent). All wounds healed completely at three months. Intestinal obstruction occurred in three patients (3 percent). No complication of the pedicled omentoplasty was observed. CONCLUSIONS: This study demonstrated that sutured perineal omentoplasty is possible in the majority of patients after abdominoperineal resection for adenocarcinoma of the lower rectum with excellent primary perineal wound healing.

[Ampullectomy in benign lesion: indications and results]. / Ampullectomies pour lésions a priori bénignes: indications et résultats.

BACKGROUND: Surgical resection remains today the standard treatment of ampullary and papilla tumours. Whether pancreaticoduodenectomy (PD) or ampullectomy is indicated for presumed benign lesions remains debated. The feared potential post-operative morbidity of ampullectomies is balanced by the functional sequelae of PD. AIM OF THE STUDY: This work reports our experience of ampullectomies for presumed benign lesion of the ampulla and papilla and analyses the indications and results of ampullectomies, considering both our series and published series of the literature. METHODS: Since 1997, eight ampullectomies with frozen section have been performed for presumed benign lesions, taking account of morphologic criteria and pre-operative endoscopic biopsies. RESULTS: Post-operative mortality was nil. Post-operative morbidity included one bilio-enteric fistula and four acute pancreatitis, all treated conservatively. Final pathological examination showed one benign and one malignant ampullomas, one benign fibrous stenosis of the papilla, one duodenal duplication and one choledococele, two adenomas and one adenomyomatosis of the papilla in patients with familial adenomatous polyposis (FAP). During follow-up, one de novo duodenal adenoma in FAP and one benign stenosis of the papilla were observed and treated endoscopically. All other patients remain asymptomatic. CONCLUSION: Ampullectomy with accurate intra-operative frozen section appears adequate for presumed benign lesion of the papilla and ampulla.