Obstructed defaecation syndrome: European consensus guidelines on the surgical management.

Clinical decision-making in the treatment of patients with obstructed defaecation remains controversial and no international guidelines have been provided so far. This study reports a consensus among European opinion leaders on the management of obstructed defaecation in different possible clinical scenarios.

Recurrence after perineal rectosigmoidectomy: when and why?

AIM: Reported recurrence rates after perineal rectosigmoidectomy (Altemeier's procedure) in patients with full-thickness rectal prolapse vary from 0% to 60%. The object of this study was to analyse risk factors for recurrence after this procedure. METHOD: From May 2004 to December 2012, 63 consecutive patients suffering from full-thickness rectal prolapse undergoing perineal rectosigmoidectomy were included. Of these 46 were female and the median age of the whole group was 79 (30-90) years. The median follow-up was 53 (3-99) months. Patient characteristics and operative parameters were compared between patients with and without recurrence. RESULTS: One patient died and another patient needed re-operation. Eight full-thickness recurrences occurred in eight patients after a median of 18 (6-48) months. Stapled compared with handsewn anastomosis (hazard ratio 7.96, 95% confidence interval 1.90-33.47; P = 0.001) and shorter specimen length (hazard ratio 4.06, 95% confidence interval 0.97-16.99; P = 0.03) increased the risk of recurrence in Cox regression analysis. CONCLUSION: The operative technique including stapled anastomosis and length of the resected specimen seems to be associated with a high recurrence rate after perineal rectosigmoidectomy.

[Operative therapy of chronic inflammatory bowel diseases. Indications and importance]. / Operative Therapie chronisch-entzündlicher Darmerkrankungen. Indikationen und Stellenwert.

BACKGROUND: The impact of surgery in the treatment of inflammatory bowel disease (IBD) is considered as secondary whereas conservative treatment remains the first choice. Surgery is designated for a complicated or refractory disease course. Furthermore, there seems to be prophylactic aspects as well, such as ileocecal resection in Crohn's disease and prophylactic restorative coloproctectomy for intraepithelial neoplasia associated with ulcerative colitis. AIM: This review evaluates the impact of surgery in the treatment of Crohn's disease and ulcerative colitis in view of existing data in the literature. MATERIAL AND METHODS: The results in the literature are reviewed and retrospective data from this institution are presented. RESULTS: The manifestation of Crohn's disease is mainly ileocecal, colorectal, enteric and anorectal. The role of surgery is discussed according to the localization, extent of the disease and the clinical course. The emphasis is on longstanding Crohn's proctitis with fistulas and stenosis which are still challenging. The results indicate that intersphincteric rectal resection with pull through of the rectum and hand-sewn anastomosis represents a good option in up to 67 % of cases to avoid permanent stoma in highly selected patients. In addition, this procedure provides high rates of fistula healing as well as low recurrence rate of the anorectal stenosis. Pouch surgery in ulcerative colitis can be offered in high volume centers with low morbidity and functional results remain stable over time. Postoperative quality of life seems to be good with regard to general and disease-related quality of life. DISCUSSION: Interdisciplinary approaches should increasingly focus on prophylactic aspects of surgical options while conservative treatment will be enhanced by new therapeutic agents.

Impact of peritoneal carcinomatosis in the disease history of colorectal cancer management: a longitudinal experience of 2406 patients over two decades.

BACKGROUND: Recent therapeutic developments demand for an update of information on natural history, risk factors and prognosis of peritoneal carcinomatosis (PC) of colorectal origin. Therefore, prospective registry data should provide information about incidence, predictors and outcome. METHODS: From a prospectively expanded single-institutional database with 2406 consecutive patients with colorectal cancer (CRC), clinical, histological and survival data were analysed for independent risk factors and prognosis. Findings were then stratified to the era of treatment without chemotherapy, 5-Fluorouracil-only and contemporary systemic chemotherapy, respectively. RESULTS: Overall, 256 (10.6%) patients were diagnosed with PC thereof 141 (5.85%) with metachronous PC. Independent risk factors for the development of metachronous PC were age <62 years, N2-status, T4-status, location of the primary in the left colon or appendix. In the era of contemporary systemic chemotherapy, prognosis for PC improved only not-significantly (median survival of 17.9 months vs 7.03 months, P=0.054). CONCLUSION: Despite improvement in the overall outcome with prolonged median survival for the complete patient cohort with CRC, those patients with PC have not experienced the same benefit. In the era of contemporary systemic chemotherapy, progress in treatment resulted in only limited survival benefit. Thus, continuous efforts for further therapeutic advancements should be undertaken in these patients diagnosed with PC.

Perineal rectosigmoidectomy: quality of life.

AIM: For any surgical treatment of full-thickness rectal prolapse, little attention has been given to quality of life (QoL). This study prospectively evaluated continence, constipation and QoL after perineal rectosigmoidectomy for full-thickness rectal prolapse in young and elderly patients in the long term. METHOD: From May 2003 to May 2010, consecutive patients suffering from full-thickness rectal prolapse and treated with perineal rectosigmoidectomy were prospectively studied. A standardized questionnaire, including the Cleveland Clinic Constipation Score (CCCS), the Cleveland Clinic Incontinence Score (CCIS) and generic [EuroQol five-dimension (EQ-5D)] and constipation-specific [Patient Assessment of Constipation-Quality of Life (PAC-QOL)] QoL scores, was administered pre- and postoperatively. The Wilcoxon test (for EQ-5D data) and two-sample Student's t-test [for EuroQol visual analogue scale (EQ-VAS), CCCS, CCIS and PAC-QOL data) were used for statistical analyses. RESULTS: Fifty-three patients (47 women), 72.7 (range 30-89) years of age, underwent perineal rectosigmoidectomy. One patient died and one patient needed reoperation. Five full-thickness recurrences occurred. Thirty-seven patients completed the follow-up questionnaire at a median of 49 (range, 6-89) months. Postoperative incontinence and constipation improved significantly (CCIS from 13 ± 7.28 to 8.7 ± 6.96 and CCCS from 8.32 ± 6.96 to 3.49 ± 4.17). Furthermore, QoL, in terms of mobility, usual activity, pain/discomfort and anxiety/depression and subjective state of health, were significantly better at follow-up (P < 0.001). All dimensions of constipation-related QoL improved (P < 0.001). The results did not differ significantly between patients under or over 69 years of age. CONCLUSION: Patients' experience improved general and constipation-related QoL after perineal rectosigmoidectomy, and this was independent of age.

Predictive factors for postoperative constipation and continence after stapled transanal rectal resection.

BACKGROUND: Although stapled transanal rectal resection (STARR) has become an important surgical option in the treatment of obstructive defaecation syndrome, objective data about parameters that predict its success or failure are not yet available. METHODS: Medical history, clinical and radiomorphological data were obtained prospectively from a multi-institutional STARR registry. Predictive factors for postoperative constipation (Cleveland Clinic Constipation Score, CCS) and incontinence (Cleveland Clinic Incontinence Score, CCIS) were identified using univariable and multivariable analysis. RESULTS: Data were obtained for 181 of 201 patients in the STARR registry, with completed median follow-up of 19·4 (range 12-41) months. Although the CCS decreased significantly overall (from mean(s.d.) 16·3(4·9) to 6·7(4·1); P < 0·001), 31 patients (17·1 per cent) complained about persisting constipation. CCIS levels remained unchanged overall, but 16 patients (8·8 per cent) had new-onset faecal incontinence. Multivariable analysis revealed that rectocele (ß = -0·302, P < 0·001) and intussusception (ß = -0·392, P < 0·001) were independent predictors of low CCS levels, and intussusception (ß = -0·216, P = 0·001) and enterocele (ß = -0·171, P = 0·012) were independent predictors of low CCIS levels. In contrast, small rectal diameter (ß = -0·293, P < 0·001), low squeeze pressure (ß = -0·188, P = 0·005) and increased pelvic floor descent at rest (ß = 0·264, P < 0·001) predicted high CCIS levels. CONCLUSION: Factors for a favourable outcome after STARR included rectocele, intussusception and enterocele, whereas small rectal diameter, low sphincter pressure and increased pelvic floor descent were unfavourable. These findings should be integrated into the therapy algorithm for STARR.

Stapled transanal rectal resection and sacral nerve stimulation - impact on faecal incontinence and quality of life.

AIM: The aim of the study was to assess the impact of stapled transanal rectal resection (STARR) on pre-existing faecal incontinence and quality of life in patients suffering from obstructive defaecation syndrome (ODS) and to evaluate the efficiency of sequential sacral nerve stimulation (SNS) for improvement of persistent incontinence after STARR. METHOD: Thirty-one patients with ODS and major faecal incontinence prior to STARR were prospectively enrolled. The outcome was measured using the Cleveland Clinic Constipation and Incontinence score (CCS, CCIS), Faecal Incontinence Qualities-of-Life Index (FIQL), Patient Assessment of Constipation Quality-of-Life (PAC-QOL) and EuroQol visual analogue scale (EQ-VAS). RESULTS: The overall levels of constipation (CCS from 13.1 ± 3.8 to 6.2 ± 5.4; P < 0.001) and incontinence (CCIS from 12.6 ± 3.2 to 9.4 ± 5.1; P = 0.005) were significantly improved after STARR; concordantly, the global and specific quality of life were significantly improved. Following postoperative constipation and incontinence, three different groups of patients were differentially referred to SNS. In group I (n = 16, 52%), both constipation (CCS from 12.6 ± 4.0 to 3.6 ± 1.9; P < 0.001) and incontinence (CCSI from 12.43 ± 3.2 to 5.1 ± 1.9; P < 0.001) were improved. In group II (n = 8, 25%), only constipation was improved (CCS from 12.3 ± 2.3 to 3.3 ± 2.2; P < 0.001), while incontinence persisted (CCIS from 12.8 ± 2.9 to 13.1 ± 3.1; P > 0.05). In group III (n = 7, 23%) there was no improvement at all. Sacral nerve stimulation was successfully carried out in six (85%) of seven patients in group II (post-SNS CCSI 6.1 ± 1.7; P = 0.01) but failed in five of five patients in group III. CONCLUSION: Stapled transanal rectal resection improves quality of life in ODS patients with both severe constipation and faecal incontinence. Sacral nerve stimulation may efficiently improve persisting incontinence after STARR in selected patients.

[Stapled transanal resection for the treatment of obstructed defaecation syndrome]. / Die STARR-Operation zur Therapie des obstruktiven Defäkationssyndroms.

Stapled transanal rectal resection (STARR) has become a well-evaluated surgical procedure for the treatment of outlet obstruction in the context of conservative refractory obstructed defaecation syndrome (ODS). The diagnosis of ODS needs to be objectified which can be best ensured by clinical scoring systems. Besides a general coloproctological examination, dynamic defecography represents the most important diagnostic procedure. Pelvic floor dyssynergia and slow transit constipation should always be taken into account for the differential diagnosis and for which the STARR procedure is generally contraindicated. Surgery is performed via a transanal approach using a full thickness rectal resection of either the ventral or dorsal proportion of the rectal wall in the PPH01 conventional procedure or circumferentially by monoblock resection in the contour transtar® procedure. Morbidity is best characterised by data of the European STARR registry which contains a total number of n = 2,838 consecutive patients. The overall morbidity rate was 36 % whereby urgency (20 %) and bleeding (5 %) were the most frequent complications. More favourable data have been published in single centre studies. Functional results are available with a follow-up of 1 year up to 68 months postoperatively. Response rates of up to 90 % were reported whereas recurrence rates were given with a maximum of 18 % at 68 months follow-up. In summary, the STARR procedure provides good functional results in conservative refractory outlet obstruction with minor morbidity and the outcome seems to remain stable in the long-term follow-up.

Enterocele is not a contraindication to stapled transanal surgery for outlet obstruction: an analysis of 170 patients.

AIM: Enterocele is common among patients suffering from obstructive defecation syndrome (ODS), but it is often considered a contraindication for stapled transanal surgery. The functional results and complication rates were compared in patients with or without enterocele who were treated with stapled transanal rectal resection (STARR) for ODS. METHOD: Patients presenting with ODS were evaluated using standardized clinical and radiological investigations. A total of 170 patients were treated with either PPH01-STARR or Contour Transtar® and were followed up for a median of 18 months. RESULTS: On preoperative defecography, 55 (32%) of 170 patients were found to have an enterocele. The preoperative Cleveland Clinic Constipation Scores (CCCS) in patients with and without enterocele were (mean ± standard deviation) 15.9 ± 5.4 and 15.4 ± 5.2, respectively. At 18 months postoperatively the CCCS were 8.5 ± 2.7 and 8.1 ± 2.6 (P < 0.001), respectively, in patients with and without enterocele. Morbidity was 7.3% (n = 4) in patients with enterocele (anal pain, n = 1; minor bleeding, n = 2; and acute urinary retention, n = 1) and 7.0% (n = 8) in patients without enterocele (anal pain, n = 3; minor bleeding, n = 3; acute urinary retention, n = 1; and staple line dehiscence, n = 1). There were no cases of pelvic sepsis, small bowel injury or postoperative ileus. No patient needed surgical re-operation. CONCLUSION: There was no difference in functional outcome and postoperative complications in patients with and without enterocele undergoing STARR for ODS.

[Cost analysis of the fast track concept in elective colonic surgery]. / Kostenanalyse des Fast-Track-Konzeptes bei elektiver Kolonchirurgie.

INTRODUCTION: Fast track (FT) is a modern concept to enhance postoperative recovery after elective surgery. It has been approved during the last years. Beside its medical benefits, fast-track (FT) concepts may provide an economic incentive, although a cost-benefit analysis in the daily clinical routine has not yet been realised. In addition to this an elevated consumption of resources is postulated. PATIENTS AND METHODS: In 2007 we prospectively studied the implementation of the FT concept for elective colonic surgery in the daily clinical routine at the Department of General Surgery of Nuremberg Hospital. In a representative subgroup of patients studied, we performed a cost-cost analysis by comparing these patients to a retrospectively analysed group that had been treated in a conventional traditional manner in 2002. RESULTS: 369  patients were included and treated according to the FT concept. Discharge criteria were met at the 4(th) postoperative day in median (SD 3.9  days, minimum  1, maxiumum 29  days). The rate of general postoperative complications was 24.4 % (16 % minor complications) for all patients and 6.6 % in the group of patients who were discharged within 9 postoperative days or less (n=182). With respect to the main FT items, implementation of the FT concept was considered as effective. Cost-cost analyses showed a cost reduction of 32 % in favour of patients treated with the FT concept. CONCLUSION: This study clearly shows the clinical and economic benefits of the FT concept considering health services research. Therefore further clinical implementation of the FT concept seems beneficial, not only in the view of medical aspects, but also for economic reasons.

Quality of life after transperineal rectosigmoidectomy.

BACKGROUND: : This study evaluated continence, constipation and quality of life before and after perineal rectosigmoidectomy for full-thickness rectal prolapse. METHODS: : Consecutive patients with full-thickness rectal prolapse undergoing perineal rectosigmoid- ectomy (Altemeier's procedure) between May 2004 and June 2008 were studied. A standardized questionnaire, including the Cleveland Clinic Constipation Score (CCCS), Cleveland Clinic Incontinence Score (CCIS) and quality of life scores (EuroQol-Five Dimensions, EuroQol-Visual Analogue Scale and Patient Assessment of Constipation-Quality of Life (PAC-QOL)), was administered before and after operation. RESULTS: : Thirty-eight patients (32 women) of mean(s.d.) age 75(13) years underwent rectosigmoid- ectomy. Seven patients developed postoperative complications and one died. There was one recurrence 5 months after surgery. Twenty-nine patients completed the follow-up questionnaire and were reviewed after a median of 24 (range 6-48) months. Constipation and incontinence were significantly improved after surgery (mean CCCS from 10.21 to 3.58 and CCIS from 14.17 to 11.42; P < 0.001). Quality of life, in terms of mobility, usual activities, pain/discomfort and anxiety/depression, were significantly better at follow-up (P < 0.001), as was subjective health status (P < 0.001). The PAC-QOL score improved significantly in all dimensions (P < 0.001). CONCLUSION: : Transperineal rectosigmoidectomy improves general and constipation-related quality of life with good functional results.

Comparative study of Contour Transtar and STARR procedure for the treatment of obstructed defecation syndrome (ODS)--feasibility, morbidity and early functional results.

AIM: Stapled transanal rectal resection (STARR) is a promising new treatment for obstructed defecation syndrome (ODS). It may be performed using either a double-stapling technique (PPH-STARR) or with the new Contour Transtar (CT) device. The aim of this study was to evaluate the two techniques with respect to morbidity and functional outcomes. METHOD: Patients presenting with ODS were evaluated using standardized clinical and radiological investigations and prospectively entered into a database. A total of 150 Patients were treated with either PPH-STARR (n = 68) or CT (n = 82) and further evaluated at 12 month postoperatively. RESULTS: The mean size of the resected specimen was 27 cm(2) (SD +/-4.86 cm(2)) in the PPH-STARR group and 46 cm(2) (SD +/-10.6 cm(2)) in the CT group [P < 0.001]. Morbidity was 7.3% (n = 5) in the PPH-STARR group and 7.5% (n = 6) in the CT group. The most common complication was minor postoperative bleeding in both groups (PPH-STARR: n = 2, 2.9%; CT: n = 2, 2.4%) Overall there were no septic complications and no surgical re-interventions. There was a tendency for more postoperative pain following CT (n = 3, 3.6%) as compared with PPH-STARR (n = 1, 1.4%). Constipation Scores (CCS) were 15.50 +/- 5.71 in the PPH-STARR group and 15.70 +/- 5.84 in the CT group preoperatively and decreased significantly to 8.25 (SD +/-1.45) and 8.01 (SD +/-2.31) 12-months after surgery. Values did not differ significantly between the two groups. CONCLUSIONS: Contour Transtar is as safe and effective as PPH-STARR and provides a true circumferential resection of rectal intussusception. This may benefit selected patients and result in improved long-term durability of the technique.

Outcome after resection of one hundred gastrointestinal stromal tumors.

AIMS: To evaluate the outcome after surgical resection in patients with gastrointestinal stromal tumors and to determine the factors influencing local tumor recurrence or distant metastatic disease after locally complete tumor resection (R0). METHODS: Outcomes of 100 patients with primary gastrointestinal stromal tumors (GIST) surgically managed between 1997 and 2006 at a single institution were reviewed. Univariate and bivariate analyses were used to determine factors affecting recurrence-free and tumor-free survival. RESULTS: All patients (n = 100) had c-kit-positive GIST. There were 17% (n = 17) very low risk, 41% (n = 41) low risk, 19% (n = 19) intermediate risk and 23% (n = 23) high risk GIST originating from the stomach, small bowel, colon and rectum. The median patient age was 68 years (range 39-92). Seventy-three percent of the patients had symptomatic local disease. Most (94%; n = 94) of them underwent R0 resections of their primary tumor. R0 resection was significantly associated with a lower tumor-related mortality rate (p = 0.0001). The patients with recurrence/metastases had significantly larger tumors (p = 0.0017) and a mitotic index higher than 5/50 HPF (p = 0.0001). Seven of 20 patients from the high-risk group and 2 of 7 patients with metastatic disease developed local recurrence or further metastatatic tumor spread following R0 resection. CONCLUSION: Surgical removal continues to be the mainstay of GIST treatment. R0 resection, tumor size and mitotic index are significant prognostic factors. Overall, more than 30% of the patients with high-risk GIST develop local recurrences and distant metastases despite R0 resection. Additional molecular pathological markers are needed to yield a more accurate tumor profile and to thus achieve a better predictability of the biological behavior of GIST.

Improving laser-induced thermotherapy of liver metastases--effects of arterial microembolization and complete blood flow occlusion.

INTRODUCTION: A prerequisite for an oncologically curative application of laser-induced thermotherapy (LITT) of liver metastases is complete tumor destruction. This increased effectiveness was achieved experimentally by combining LITT with interrupted hepatic perfusion. The aim of this study was to evaluate whether an interventional selective arterial microembolization might be as effective as complete blood flow occlusion using an open Pringle's maneuver. PATIENTS AND METHODS: We included patients with unresectable colorectal liver metastases. LITT was performed without interrupted hepatic perfusion (control group) compared to LITT in combination with interrupted perfusion either by embolization of intraarterial degradable starch microspheres (DSM) (percutaneous access) or by complete hepatic inflow occlusion (Pringle's maneuver; open access). Online monitoring was performed using intraoperative ultrasound or MRI. Volumetric techniques were used to assess metastases and postinterventional lesions. RESULTS: Fifty-six patients with 104 metastases (control group (25), DSM (37), and Pringle (42)) were treated. The preinterventional tumor volumes were significantly smaller than the postinterventional lesion volumes (control group: 9.8 vs. 25.3 cm3; DSM: 9.5 vs. 65.4 cm3; Pringle: 12.9 vs. 76.5 cm3). The morbidity rate was 21.4% without treatment-related mortalities. After 6 months follow-up, tumor recurrence was diagnosed in 6 patients (control group (4), LITT with DSM (1), and Pringle (1)). CONCLUSIONS: Combining LITT with blood flow occlusion leads to a significant increase in lesion size. The application of DSM offers a safe and effective alternative to the open access with Pringle's maneuver. Compared to LITT-monotherapy, this modality achieves significantly larger thermal lesions with the need of fewer applications.

[Transtar™ operation for rectocele and obstructed defecation syndrome]. / Transtar™-Operation bei Rektozele und obstruktivem Defäkationssyndrom.

The Contour® Transtar™ operation represents a further methodological development of conventional transanal stapled rectal resection (STARR) for the treatment of obstructed defecation syndrome (ODS) and/or full thickness rectal prolapse. In contrast to the conventional STARR technique a specially designed single curved stapler is used with which the rectal wall is incised in a circular fashion and anastomosed. This results in a monoblock resection with almost unlimited extent of resection. In multicenter studies the procedure has generally been shown to be effective for treatment of ODS with intussusception and rectocele. In comparison to conventional STARR the resected tissue samples are larger and the functional effectiveness is comparable. Furthermore, data from prospective randomized trials revealed higher effectiveness in long-term follow-up. With reference to full thickness rectal prolapse, feasibility studies have been performed which showed low morbidity but long-term follow-up studies suggest a high recurrence rate of >40 %.

[Nonoperative ablation for liver metastases. Possibilities and limitations as a curative treatment]. / Nichtoperative Ablation. Möglichkeiten und Grenzen der Ablationsverfahren zur Behandlung von Lebermetastasen unter kurativer Intention.

Under the term "nonoperative ablation" are grouped a number of heterogeneous approaches for the treatment of liver metastases, including laser-induced thermotherapy (LITT), radio-frequency therapy (RF), and cryotherapy. In general these procedures had been intended only for palliative purposes. The establishment of clinically relevant lesion size and a lack of long-term survival data were regarded as main limitations to using them with curative intention. During the last years however, new application systems have demonstrated remarkable results in RF and LITT, and some clinical studies have shown long-term survival in selected patients comparable to that for hepatic resection. We review possibilities and limitations of nonoperative ablation procedures with curative intent, highlighting the histopathological bases of thermal ablation techniques and clinical aspects such as R0 ablation and long-term survival.

Laser-induced thermotherapy: intra- and extralesionary recurrence after incomplete destruction of experimental liver metastasis.

PURPOSE: The aim of this study was to determine the energy (J/mm3 tumor volume) and temperature required for a complete laser-induced thermotherapy (LITT) of experimental liver tumors, and to find out causes and areas of local recurrence followed by incomplete treatment. METHODS: In VX-2 tumor-bearing rabbits LITT was performed using neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (1064 nm) with a diffuser-tip applicator and a temperature feedback system. The animals were randomized into four groups (n = 20) that differed in the target temperature at the tumor border as follows: 45 degrees C, 50 degrees C, 55 degrees C and 60 degrees C. The target temperature was held for 10 min constant. Histologic examination (hematoxylin and eosin [H and E], nicotinamide adenine dinucleotide phosphate [NADPH]-dehydrogenase) was performed at 0 h, 24 h, 96 h, and 14 days after LITT. RESULTS: The pretreatment tumor volume of 2191 +/- 61 mm3 was the same for all groups (p > 0.05). Energy up to target temperature and total energy required, lesion size, and the rate of incomplete tumor ablation (recurrences) are listed below (ap < 0.05, Kruskal-Wallis test). Histologically, two forms of local recurrences could be differentiated intralesionary and extralesionary. CONCLUSIONS: To achieve complete in situ ablation under the given conditions, it is necessary to apply laser energy of 3 J/mm3 tumor volume. A minimum temperature of 60 degrees C on the tumor border presumed an application of 10 min. Recurrence was found outside the coagulation zone (extralesionary) and in high vascularized areas within the coagulation zone (intralesionary).

[Laser-induced thermotherapy (LITT) for liver metastasis in an open 0.2T MRI]. / Laserinduzierte Thermotherapie (LITT) von Lebermetastasen in einem offenen 0,2T MRT.

OBJECTIVE: To test the feasibility and safety of the laser-induced thermotherapy (LITT) for liver metastases in open MR imaging system operating at 0.2 Tesla. METHOD: Laser therapy using the Nd:YAG laser was performed on 25 patients with a total of 41 liver metastases. An open low-field MRI scanner was used for puncture, positioning of the laser applicator, and monitoring the therapy. A true FISP sequence was used to track the puncture in close to real-time. Localization diagnostics and temperature monitoring were aided by T1-weighted gradient echo sequences in the breath-holding technique. In the first follow up after 24-48 hours, a contrast-enhanced T1-weighted gradient-echo sequence was performed in an MRI scanner at 1.5T. The pre-, intra- and postinterventional volumes of the liver metastases as well as the thermolesions and the thermonecroses were determined. RESULTS: LITT in an open MRI system was technically feasible in all patients with no clinically relevant complications. The mean volumes of the thermolesions measured during intervention in low-field MRI were lower than the volumes of the thermonecroses measured after intervention in high-field MRI. CONCLUSION: The technique presented here of laser-induced thermotherapy for liver metastases in an open MRI system is technically feasible and safe.

[Laser-induced thermotherapy. Technical prerequisites for treatment of malignant liver tumors]. / Laserinduzierte Thermotherapie. Technische Voraussetzungen zur Behandlung maligner Lebertumoren.

Laser-induced thermotherapy is an in situ ablation method for the local treatment of liver tumors. The basic prerequisite for induction of adequate treatment volumes for clinical use was the development of a thermostable application system. In an ex vivo test series, the specially developed application system (diffuser tip) with 5760 J had a higher thermic loading capacity than the Ringmode applicator with 4200 J, thus enabling the induction of significantly larger lesions with a volume of 7.6 cm3. The results of a further in vivo test series demonstrated that the lesions were subject to a four-phase connective-tissue organization within a 6-month period. Furthermore, the same laser energy (4200 J) was associated with a significantly lower lesion volume of 2.5 cm3 in the in vivo than in the ex vivo test series. The influence of liver perfusion on the inducible lesion volume was examined in a further animal experimental study. By temporarily interrupting hepatic blood perfusion (Pringle's maneuver) during laser application, the effective volume could be increased to 50.3 cm3 (P < 0.01) using an optical beam splitter. These results show that the technical prerequisites for reliable clinical application of laser-induced thermotherapy have been fulfilled.