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- Gadan, Soran, 1976-
(author)
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Long term aspects of defunctioning stoma following low anterior resection for rectal cancer
- 2020
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Doctoral thesis (other academic/artistic)abstract
- In Sweden, more than 2 000 individuals are diagnosed with rectal cancer each year. Surgery is the main curative treatment, and involves removal of the tumor with the surrounding mesorectum in adefined anatomical plane. Intestinal continuity is restored by anastomosing the colon to the rectalstump at the pelvic floor. Leakage of the anastomosis is a potentially life-threatening complication, and is most common in low anastomoses located at the pelvic floor. A temporary defunctioning loop stoma (DS) reduces both the rate of leakage and the severity when leakage occurs despite DS. The use of DS has increased substantially in Sweden over the last 15 years, especially in low anastomoses at the level of the pelvic floor. The purpose of this thesis was to increase the understanding of different aspects of DS and its impact on anorectal function, long-term survival, cancer recurrence, timing of stoma reversal, and the risk of having a permanent stoma.In Paper I, the LARS score questionnaire was used to assess anorectal function among patients who had participated in a Swedish nationwide randomized trial. Those who had a DS (n=116) were compared to those without DS (n=118). After a median follow-up time of 12 years, patients with DS had a poorer bowel function than those without DS in terms of incontinence for gas and loose stools. No differences were found with regard to fecal incontinence, defragmentation, and urgency. Women and patients who had received preoperative radiotherapy had poorer anorectal function. Impaired anorectal function was associated with lower self-perceived health.In Paper II, a cohort of 110 patients from Örebro Region, Sweden, was investigated with regard to whether or not the DS was reversed within a 4-month period. Only 25% had their stoma reversed within this timeframe. Moreover, a third of the patients had a delayed stoma closure without any identifiable medical reason. This was an improvement compared to a previous study from the same region, which found that 58% of patients operated between 1995 and 2007 had a delayed stoma reversal without any identifiable medical reason. The most common cause for delayed DS reversal in our study was adjuvant chemotherapy (38%).In Paper III, the impact of DS on long-term survival and local and distant cancer recurrence was investigated in a nationwide population-based study cohort operated with low anterior resection (LAR) between 1995 and 2010 (n=4130), retrieved from the Swedish Colorectal Cancer Registry. Patients with a DS at LAR (n=2163) had an increased survival rate during the first 3 years afterindex surgery in comparison with those without a DS. Beyond 3 years of follow-up, no difference was noted between the two groups. There were no differences regarding either local cancer recurrence or distant metastases between patients with and without DS.In Paper IV, the risk of having a permanent stoma beyond 5 years after rectal cancer surgery was evaluated in 232 patients (excluding mortality within 90 days; n=2) previously randomized to DS or no DS. After a median follow-up of 15 years, 25% (57/232) had a permanent stoma. Of these, 23% (13/57) had their permanent stoma constructed at median 10 years after the index surgery. The incidence of permanent stoma was numerically lower in the group originally randomized to DS, but this difference was not statistically significant. Anastomotic leakage was the most common riskfactor for ending up with a permanent stoma.
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| 2. |
- Boström, Petrus, 1981-
(author)
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Rectal cancer : the influence of surgical technique on morbidity, mortality and survival
- 2020
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Doctoral thesis (other academic/artistic)abstract
- Surgery is still the most common treatment for rectal cancer, being the most effective and cost-efficient modality. However, it is not without risk, nor without controversies. This dissertation is an evaluation of the pros and cons of high versus low ligation, whether anastomotic leakage is still prevalent after surgery and associated with increased mortality, and if the risk of leakage could be predicted by early postoperative pain.Study I relied upon case records and registry data to evaluate the causal effect of high ligation on the risk of anastomotic leakage after anterior resection in 722 patients with increased cardiovascular risk. When controlling for confounders, no association was found overall. However, an increased risk for leakage after high ligation was noted for the few patients who suffered from both manifest cardiovascular disease and ASA III–IV (OR 3.66, 95% CI 1.04–12.85) and when performed in a low volume hospital (OR 3.89, 95% 1.58– 9.59). Study II estimated the risk of anastomotic leakage and death after anterior resection today. Among the 6,948 patients, 10.0% suffered from leakage, in whom mortality was 3.9% versus 1.5% for patients without a leak. However, this increased mortality was driven entirely by patients in need of reintervention, who exhibited a 7.5% 90-day mortality, resulting in a significantly increased risk (OR 5.57, 95% CI 3.29–9.44), when controlling for confounders, while conservatively treated leakage was not associated with mortality. Age acted as an effect modifier, as postoperative mortality after leakage was increased in the elderly.Study III returned to high versus low ligation as exposure, to evaluate the long-term oncological benefits of either ligation level, with cancer-specific survival as primary outcome. The final cohort of 8,287 patients who underwent abdominal surgery for rectal cancer, with curative intent, was followed for a minimum of 3.5 years. After propensity score matching, no significant differences were found between high and low ligation for any survival or recurrence analysis, nor in the unmatched cohort, when controlling for confounders. A statistically significant difference was found for lymph node harvest, which was slightly greater in high ligation (17.7 vs 16.7 lymph nodes). Finally, study IV estimated the independent predictive ability of postoperative pain, measured on the numerical rating scale (NRS), on the risk for anastomotic leakage after colorectal cancer surgery. It seems as if increased early pain is an independent predictor for leakage (OR 1.73, 95% CI 1.22– 2.46 for NRS 4–10), with increasing risk of leakage with increasing pain (OR 2.42 for NRS 8–10). In addition, increased pain was more strongly associated with more severe leakage.In summary, the level of ligation seems to be of importance only in a select group of high-risk patients, but offers no obvious oncological advantages. The high incidence and serious sequelae of anastomotic leakage makes it one of the most important clinical challenges in colorectal surgery, with especially detrimental effects in the elderly. A better understanding of the causal pathways behind leakage, and the overall harm and benefit of ligation level and diverting stomas, might allow a better selection of treatment for future patients.
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