Endoscopic stenting in gastrointestinal tract

Gastric outlet obstruction (GOO) is a preterminal event in incurable malignancies of the gastrointestinal tract. Pancreatic cancer and gastric cancer are the most common causes for GOO. Colorectal cancer (CRC) is the most common etiology for colorectal obstruction (CRO). Other causes for CRO include extracolonic malignancies (ECM) and benign causes. Traditional treatment of GOO and CRO is surgery, but it carries a high rate of complications. Self-expanding metal stents (SEMS) have become an alternative for surgery in GOO and CRO. The aim of this work was to evaluate the results of endoscopic stenting (ES) in GOO and CRO. The study material consisted of 323 patients with GOO or CRO treated at Meilahti Hospital between January 1998 and December 2010. In study I, 104 patients with incurable GOO were included in the analysis. The study II population consisted of 97 patients with advanced gastric cancer and GOO, and of these 50 underwent ES, 26 palliative resection (PR), and 21 gastrojejunostomy (GJ). In study III, 21 patients with benign CRO were included in the analysis. The study IV population comprised 101 patients with malignant CRO, and of these 11 were stented as a bridge to surgery. In study IV, 66 underwent palliative stenting due to CRC and 24 due to ECM. In study I, a median GOOSS (gastric outlet scoring system) improved significantly from 0 to 2 after stenting, and 73% of the patients managed with one stenting procedure until death. In study II, ES resulted in a more rapid improvement in oral intake and a shorter hospital stay than GJ or PR. Complication rates were similar between the groups. In the PR group, symptom-free and overall survivals were longest. In multivariate survival analysis, independent prognostic factors were age, BMI, pre-procedure GOOSS, PR as treatment modality, and chemotherapy. In study III, 63% of anastomotic strictures (AS) were resolved with SEMS. Of diverticular strictures (DS), 30% were resolved with SEMS. Complication rate was 43%. Of the complications, 67% occurred for patients with DS or Crohn`s disease strictures. In study IV, a primary anastomosis rate in elective operations was 90% in the bridge to surgery group. In palliative stenting, clinical success rates were significantly lower for patients with ECM than for patients with CRC (63% vs. 94%, p<0.001). Between palliation groups, complication, operation, and stoma rates were similar. SEMS provides good palliation for patients with incurable GOO. In advanced gastric cancer and GOO, SEMS is a treatment of choice for patients unfit for surgery. PR seems to provide survival benefit, and should be considered as a treatment option for patients fit for surgery. In benign CRO, SEMS is a good treatment option in AS for selected patients. In DS and Crohn`s disease strictures, a high rate of complications limit the utility of SEMS. In malignant CRO, SEMS can be used as a bridge to surgery and as palliation. A higher clinical failure rate is associated with palliative stenting for ECM than for CRC.Haima- ja mahasyöpä ovat yleisimmät syyt mahasuolikanavan yläosan tukoksille ja paksusuolisyöpä mahasuolikanavan alaosan tukoksille. Yleensä mahasuolikanavan tukokset on hoidettu leikkaamalla. Leikkaushoitoon liittyy kuitenkin runsaasti sairastavuutta. Tukospotilaiden yleiskunto on usein heikentynyt aliravitsemuksen vuoksi ennen leikkausta, mikä edelleen lisää leikkaukseen liittyviä riskejä. Endoskooppinen metalliverkkoproteesi- eli stenttihoito on vaihtoehto leikkaukselle tukoksen hoitona. Tutkimuksessa selvitettiin stenttihoidon soveltavuutta ja tuloksia mahasuolikanavan tukoksien hoidossa. Aineisto koostui 323 potilaasta, jotka oli hoidettu HUS, Meilahden sairaalassa vuosien 1998-2010 välillä pahanlaatuisen mahasuolikanavan ylä- tai alaosan tukoksen vuoksi. Osalla potilaista paksusuolitukos oli kehittynyt myös hyvänlaatuisen syyn pohjalta. Stenttihoidon avulla mahasuolikanavan yläosan tukospotilaiden syömiskyky parantui merkitsevästi. Verrattuna leikattuihin mahasyöpäpotilaisiin stenttihoidettujen potilaiden syömiskyky parantui merkitsevästi nopeammin ja myös sairaalahoitoaika oli lyhempi. Mahasyöpäpotilaat, joille tehtiin mahalaukun osapoisto tukoksen vuoksi elivät pisimpään ja monimuuttuja-analyysissä mm. potilaan syömiskyky ja mahalaukun osapoistoleikkaus hoitomenetelmänä olivat itsenäisiä ennustekijöitä elinajan suhteen. Sairastavuus hyvänlaatuisen paksusuolitukoksen stenttihoidon yhteydessä oli 43%. Jopa 2/3 komplikaatiosta aiheutui potilaille, joilla tukoksen syynä oli paksusuolen divertikuloosi eli umpipussitauti tai Crohnin tauti. Sen sijaan suoliliitoksen ahtaumien hoidossa stenttihoidolla saavutettiin hyvä hoitotulos 63%:lla potilaista. Stenttaus oli tehokas pahanlaatuisen paksusuolitukoksen oireenmukaisena hoitona, mutta tukos laukesi harvemmin, jos sen aiheuttajana oli muu kuin paksusuolisyöpä. Suoliliitos suunnitellussa syöpäleikkauksessa onnistui 90%:lle potilaista, joiden akuutti tukos oli laukaistu stenttillä ennen suunniteltua syöpäleikkausta. Stenttaus on hyvä menetelmä mahasuolikanavan yläosan tukoksien hoidossa. Mahalaukun osapoistoa tulisi harkita tukoksen hoitona leikkaukseen soveltuvilla mahasyöpäpotilailla mahdollisen elinaikahyödyn vuoksi. Hyvänlaatuisen paksusuolitukoksen stenttihoitoon liittyy paljon sairastavuutta, mutta valikoiduille suoliliitosahtauma-potilaille stenttihoito voi olla hyödyllinen. Stenttihoitoa voidaan käyttää akuutin paksuolitukoksen laukaisuun ennen suunniteltua leikkausta tai tukoksen oireenmukaiseen hoitoon levinneen syövän yhteydessä. Tulokset ovat kuitenkin paremmat, jos tukoksen aiheuttaja on primaari paksusuolisyöpä

Surgical recurrence in Crohn's disease : a comparison between different types of bowel resections

To compare recurrence frequency and location between different types of bowel resections in Crohn's disease patients. This was a retrospective study of consecutive patients undergoing bowel resection for Crohn's disease between 2006 and 2016. Type of primary operation was recorded and grouped as ileocolic resection, small bowel resection, segmental colon resection with colocolic anastomosis or colorectal anastomosis, colectomy with ileorectal anastomosis, or end stoma operation. Binary logistic regression was used to compare surgical recurrence frequency between groups. We also investigated how Crohn's disease location at reoperations was related to the primary bowel resection type. Altogether, 218 patients with a median follow-up of 4.7 years were included in our study. Reoperation was performed in 42 (19.3%) patients. The risk of reoperation using the ileocolic resection group as reference was the following: small bowel resection (odds ratio (OR) 2.95, 95% confidence interval (CI) 1.01-8.66; P = 0.049), segmental colon resection with colocolic or colorectal anastomosis (OR 6.20, 95% CI 2.04-18.87; P = 0.001), colectomy with ileorectal anastomosis (OR 26.57, 95% CI 2.59-273.01; P = 0.006), and end stoma operation (OR 4.62, 95% CI 1.90-11.26; P = 0.001). In case of surgical recurrence, the reoperation type and location correlated with the primary bowel resection type. Reoperation frequency in Crohn's disease is lower after ileocolic resection than after other types of bowel resections. Surgical recurrence in Crohn's disease tends to maintain the disease location of the primary operation. One third of Crohn's patients undergoing an end stoma operation will still need new bowel resections due to recurrence.Peer reviewe

Evidence for the role of the oxygen-evolving manganese complex in photoinhibition of Photosystem II

AbstractPhotoinhibition of PSII occurs at the same quantum efficiency from very low to very high light, which raises a question about how important is the rate of photosynthetic electron transfer in photoinhibition. We modulated electron transfer rate and light intensity independently of each other in lincomycin-treated pea leaves and in isolated thylakoids, in order to elucidate the specific effects of light and PSII electron transport on photoinhibition. Major changes in the rate of electron transport caused only small changes in the rate of photoinhibition, suggesting the existence of a significant photoinhibitory pathway that contains an electron-transfer-independent phase. We compared the action spectrum of photoinhibition with absorption spectra of PSII components that could function as photoreceptors of the electron-transfer-independent phase of photoinhibition and found that the absorption spectra of Mn(III) and Mn(IV) compounds resemble the action spectrum of photoinhibition, showing a steep decrease from UV-C to blue light and a low visible-light tail. Our results show that the release of a Mn ion to the thylakoid lumen is the earliest detectable step of both UV- and visible-light-induced photoinhibition. After Mn release from the oxygen-evolving complex, oxidative damage to the PSII reaction center occurs because the Mn-depleted oxygen-evolving complex cannot reduce P680+ normally

Risk factors for proctectomy in consecutive Crohn's colitis surgical patients in a reference colorectal centre

Purpose Crohn's colitis carries a risk for permanent stoma with extirpation of the rectum. We aimed to estimate the proctectomy rate and identify risk factors for proctectomy in patients with Crohn's colitis. Methods For this study, we retrospectively reviewed data from consecutive patients with Crohn's disease (CD) affecting the colon or anorectal region undergoing bowel resection in a reference colorectal centre between 2006 and 2016. The cumulative risk for proctectomy was calculated using the Kaplan-Meier curve. We used univariate and multivariate logistic regression analyses to determine independent risk factors for proctectomy. Outcomes after proctectomy concerning reoperation frequency and perineal wound healing are also described. ResultsIn total, this study included 125 patients. Proctectomy was performed in 36 patients (28.8%), of whom 14 patients (38.9%) experienced perineal wound healing problems. The rates of proctectomy were 5.6% and 32.0% 10 and 20 years after CD diagnosis, respectively. Female gender (odds ratio (OR) 3.375, 95% confidence interval (CI) 1.304-8.733, P=0.012), disease duration (OR 1.067, 95% CI 1.011-1.126, P=0.018) and history of perianal disease (OR 3.160, 95% CI 1.215-8.219, P=0.018) were independent risk factors for a proctectomy procedure, whereas thiopurine medication (OR 0.170, 95% CI 0.060-0.486, P=0.001) was an independent protective factor for proctectomy. Conclusions The duration of Crohn's disease, female gender and a history of perianal disease were significant risk factors for a proctectomy procedure. Future research should examine whether immunosuppressive and biological medications reduce the risk for proctectomy.Peer reviewe