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Coming dissertations at MedFak

  • Colorectal cancer : Aspects of staging, treatment, recurrence and survival Author: Åsa Collin Link: Publication date: 2023-09-29 12:19

    Colorectal cancer is the third most common malignancy in the world, and major breakthroughs have been made regarding both surgical and oncological treatment. Still, postoperative complications, such as perineal infections after abdominoperineal resection (APR), are a major cause of morbidity, and distant recurrence rate is nearly 20%. In this thesis, means to improve postoperative infection rates, nodal staging in rectal cancer (and resulting overtreatment through (chemo)radiotherapy), cancer recurrence rates and survival, were investigated. In Paper I, the effects on complication rates, recurrence rates and survival of antibiotics applied locally after an APR, by means of a gentamicin-collagen sponge in the perineal wound, were analysed in a randomized setting. No difference was seen regarding any of the endpoints. The results suggest that local antibiotics can safely be omitted in APRs. Paper II investigated the effects of mechanical bowel preparation (MBP) on cancer recurrence and survival, among colon cancer patients undergoing a colon resection. Data from the Swedish randomized MBP trial were used. After follow-up, no improvement in recurrence rates or overall survival was seen, but cancer-specific survival was improved in the MBP group. In conclusion, MBP might be a prognostic favourable factor for outcome in colon cancer patients. In Paper III, the effect of new national guideline criteria for MRI nodal staging in rectal cancer was assessed, regarding the proportion of clinically positive nodes and staging accuracy, and resulting effects on preoperative (chemo)radiotherapy use. Comparing the two years prior to guideline implementation with the two years after implementation revealed a significant decrease in the proportion clinically positive nodes, but staging accuracy remained low, and (chemo)radiotherapy rates decreased with seemingly no correlation to guidelines. Thus, new guidelines decreased the rate of clinically positive nodes, but nodal accuracy remained poor and nodal staging should perhaps not be a criterion in preoperative treatment decisions. Paper IV investigated the impact of the total mesorectal excision quality, by means of the three Quirke grades, mesorectal (best quality), intramesorectal and muscularis propria (worst quality), on recurrence and survival, and assessed risk factors for intramesorectal or muscularis propria resection. Muscularis propria grade was associated with a higher local recurrence rate, but not with distant recurrence or survival. Several factors were associated with intramesorectal and muscularis propria grade, and more caution is warranted in these patients. In conclusion, this thesis provides insight into treatment choice, and the association of day-to-day treatment details with postoperative complications, recurrence and survival rates, as well as the challenges of nodal staging.

  • On the Diagnosis and Treatment of Lumbar Spinal Stenosis Author: Konstantinos Pazarlis Link: Publication date: 2023-09-27 11:23

    Lumbar spinal stenosis (LSS) is the most common indication for spinal surgery. The aging global population is increasing the demand for strategies that promote physical activity among the elderly. As the prevalence of LSS rises, the condition gains constantly demographic and socioeconomic attention. Until recently, there has been no clear consensus regarding LSS treatment. Further, using electrodiagnostic examinations (EDX) as predictive tools to identify surgical candidates, could lead to a more tailored medical approach. Methodological issues in previous studies have left some questions unanswered. The necessity of extensive surgery for LSS remains a topic of debate among spinal surgeons, which this work addressed by analyzing data from 723 patients. 

    Parts of the work aimed to compare surgery and structured non-surgical treatment for LSS (Paper I, II, III). Furthermore, it aimed to investigate, by means of EDX, whether the degree of neurological affection correlates to the surgical outcome of LSS (Paper I, II). Additionally, this work evaluated the radiological outcome for surgical vs non-surgical treatment for LSS in terms of sagittal balance parameters (Paper III, V). Finally, parts of this thesis aimed to confirm findings from previous studies regarding DA and DF for LSS with DS (Paper IV, V). 

    The current thesis is based on two randomized controlled trials and a cohort study: the Uppsala Spinal Stenosis Trial, the Swedish Spinal Stenosis Study, and the Cohort Study on LSS with DS. Patient reported outcome measures from the Swedish National Quality Registry for Spine Surgery (Swespine) were used to collect follow-up data. 

    We concluded that at six months, surgery with decompression leads to superior clinical outcome, compared to structured physical therapy. The improvement is not affected by delay of surgery (Paper II). EDX does not add predictive value when assessing the patients for eligibility before surgery (Paper II). DA improves the spinal sagittal balance, regardless of preoperative DS (Paper III) and provides good two-year clinical outcome in LSS with DS with low rate of complications, and low need for subsequent surgery (Paper IV). New radiological stenosis was less common two years after DA than after DF, in LSS with or without preoperative DS (Paper V).

  • Deep inferior epigastric perforator flap breast reconstruction after mastectomy : An analysis of long-term outcomes and potential complications Author: Andreas Svee Link: Publication date: 2023-09-20 12:24

    This thesis evaluated the long-term effects and satisfaction with outcomes following deep inferior epigastric perforator (DIEP)-based breast reconstruction after mastectomy

    Paper I is a retrospective cohort study of women who received a unilateral DIEP in 2000–2009 (n = 225) in Uppsala. These women were compared with individually matched women who underwent mastectomy without autologous reconstruction (n = 450). Recurrence and survival were primary endpoints. Both groups demonstrated a similar risk of recurrence. However, the DIEP group had a significant survival advantage not persisting after adjusting for tumor characteristics.

    Paper II examined whether breast reconstruction using a DIEP flap is associated with volume changes or arm lymphedema symptoms. It hypothesized that compared with DIEP reconstructions without using the cephalic vein (CV), that using CV is not associated with ipsilateral lymphedema. Patients completed the Lymphedema Quality of Life Inventory questionnaire to assess postoperative lymphedema symptoms. CV was found to be potentially useful as an extra venous outflow in DIEP breast reconstructions without increasing the risk of ipsilateral arm swelling or lymphedema symptoms.

    Paper III evaluated the aesthetic outcome and satisfaction with the appearance of abdominal-based breast reconstruction in the long-term. Patients responded to the postoperative BREAST-Q model, and their photographs were at a mean of 11 years postoperatively. The outcomes of the BREAST-Q and available normative scales were compared. The photographs were assessed by two panels, comprising eight professionals and lay individuals, respectively. According to patients, professionals, and lay observers, abdominal-based breast reconstructions yielded good term aesthetic outcomes.

    Paper IV is a retrospective study of long-term changes in the donor site after harvesting the DIEP flap. Patients were invited to complete BREAST-Q questionnaires regarding the abdomen. The follow-up period was >8 years. Most participants reported no abdominal pain and expressed satisfaction with their abdominal appearance. The outcomes were compared between women with DIEP and women who underwent mastectomy for breast cancer without abdominal-based breast reconstruction. DIEP breast reconstruction did not cause donor site morbidity and women with DIEP reconstruction were more likely satisfied with their abdominal appearance.

    Briefly, DIEP flap breast reconstruction yields long-lasting favorable outcomes for women undergoing mastectomy.