Recellularization of decellularized adipose tissue-derived stem cells: role of the cell-secreted extracellular matrix in cellular differentiation.

Adipose-derived stem cells (ASCs) are found in a location within the adipose tissue known as the stem cell niche. The ASCs in the niche are maintained in the quiescent state, and upon exposure to various microenvironmental triggers are prompted to undergo proliferation or differentiation. These microenvironmental triggers also modulate the extracellular matrix (ECM), which interacts with the cells through the cytoskeleton and induces downstream events inside the cells that bring about a change in cell behaviour. In response to these changes, the cells remodel the ECM, which will differ according to the type of tissue being formed by the cells. As the ECM itself plays an important role in the regulation of cellular differentiation, this study aims to explore the role of the cell-secreted ECM at various stages of differentiation of stem cells in triggering the differentiation of ASCs. To this end, the ASCs cultured in proliferation, osteogenic and adipogenic media were decellularized and the secreted ECM was characterized. Overall, it was found that osteo-differentiated ASCs produced higher amounts of collagen and glycosaminoglycans (GAG) compared to the undifferentiated and adipo-differentiated ASCs. The two types of differentiated ECMs were subsequently shown to trigger initial but not terminal differentiation of ASCs into osteo- and adipo-lineages respectively, as indicated by the upregulation of lineage specific markers. In addition, integrin subunits alpha (α) 6 and integrin beta (ß) 1 were found to be produced by ASCs cultured on cell-secreted ECM-coated substrates, suggesting that the integrins α6 and ß1 play an instrumental role in cell-ECM interactions. Taken together, this study demonstrates the importance of the ECM in cellular fate decisions and how ECM-coated substrates can potentially be used for various tissue engineering applications.

Does the magnetic anal sphincter device compare favourably with sacral nerve stimulation in the management of faecal incontinence?

AIM: The magnetic anal sphincter (MAS) is a recent surgical innovation for severe faecal incontinence (FI). With its place in the treatment algorithm of FI yet to be defined, we report a nonrandomized comparison between MAS and sacral nerve stimulation (SNS) in a single-centre cohort of patients with FI. METHOD: Data were reviewed from prospective databases. From December 2008 to December 2010, 12 women [median age 65 (42-76) years], having FI for a median of 6.5 years, were implanted with a MAS. Sixteen women, of similar age, preoperative function scores, aetiology and duration of incontinence, and implanted with a permanent SNS pulse generator during the same period, served as a reference group. The duration of hospital stay, complications, change in incontinence and quality of life scores and anal physiology were compared between the two groups. RESULTS: The duration of follow up was similar [MAS = 18 (8-30) months vs SNS = 22 (10-28) months; P = 0.318]. Four patients with MAS experienced a 30-day complication, and the device was removed from one patient in each group. A significant improvement in incontinence (P < 0.001) and quality-of-life scores (P < 0.04) occurred in both groups. Mean anal resting pressure increased significantly in patients implanted with a MAS (P = 0.027). CONCLUSION: In this single-centre nonrandomized cohort of FI patients, MAS was as effective as SNS in improving continence and quality of life, with similar morbidity. These results can now serve as a prelude to a randomized trial comparing the procedures.

Minimally invasive ventral mesh rectopexy for complex rectocoele: impact on anorectal and sexual function.

AIM: Minimally invasive surgery for pelvic floor prolapse has recently been shown to be feasible and safe. This study presents the results of robotic-assisted and laparoscopic rectopexy for complex rectocoele, focusing on less frequently reported outcomes of bowel and sexual function. METHOD: We prospectively assessed 41 consecutive patients who underwent ventral mesh rectopexy (robotic-assisted or laparoscopic) for a symptomatic complex rectocoele from January 2009 to January 2010. Complex rectocoele was defined as having one or more of the following features: larger than 3 cm, an enterocoele or internal rectal prolapse. Patients with cystocoele underwent bladder suspension concurrently. Both groups were assessed for anatomical recurrence and function, comparing preoperative and postoperative faecal incontinence, obstructive defaecation syndrome and Gastrointestinal Quality-of-life Index scores, as well as vaginal discomfort and sexual function. RESULTS: Forty-one women underwent the procedure (16 robotic-assisted), with four (10.5%) having minor complications and two developing anatomical recurrence. There was significant relief of the commonest predominant symptoms of vaginal bulge/fullness (P<0.0001) and sexual dysfunction (P=0.02). There were three conversions to laparotomy (one robotic-assisted) and five patients declined postoperative functional assessment. In the remaining 33 patients [follow-up median 12 (8-21) months], analysis revealed no significant difference in overall functional score (P>0.740) or between patients with one or two meshes inserted (P>0.486). Only patients with a preoperative obstructive defaecation syndrome score >6 had a significant improvement postoperatively (P=0.030). CONCLUSION: Minimally invasive ventral mesh rectopexy for complex rectocoele offers satisfactory anatomical correction and functional results, with the potential for alleviating symptoms of outlet obstruction and improving vaginal comfort and sexual dysfunction.

Anal canal malignancies: a review in an Asian population.

INTRODUCTION: Anal canal malignancies are rare tumours of the gastrointestinal tract that represent less than five percent of anorectal malignancies. METHODS: We retrospectively reviewed patients with anal canal malignancies who were treated from April 1989 to December 2008. Patients were identified from a prospective database and records were analysed for age, gender, presenting symptoms, duration of symptoms, mode of diagnosis, histological subtypes, stage of disease, treatment received, duration of follow-up, recurrence rates and survival. RESULTS: A total of 61 patients were treated for anal canal malignancies, comprising 2.1 percent of all anorectal malignancies treated during the same period. There were 31 male and 30 female patients, with a median age at diagnosis of 61 (range 38-83) years. The commonest presenting symptoms were per rectal bleeding (69.4 percent) and pain (33.9 percent). The commonest histology was adenocarcinoma (50.8 percent) and squamous cell carcinoma (SCC) (40.3 percent). Patients underwent either surgery, radiotherapy, chemoradiation or a combination of modalities. The median duration of follow-up was 28 (range 1-120) months. Five patients developed recurrences after a median of 23 (range 2-36) months. The five-year overall survival and disease-free survival was 65.5 percent and 63.7 percent, respectively, with SCC showing a trend toward a better prognosis. CONCLUSION: Anal canal tumours are a rare clinical entity. They are usually present in the elderly with per rectal bleeding. They are usually treated using a multimodality approach, after the accurate establishment of histological diagnosis, which can yield reasonable survival rates.

Single-incision laparoscopic surgery for right hemicolectomy: our initial experience with 10 cases.

BACKGROUND: Published data has confirmed the oncological safety and efficacy of laparoscopic colorectal surgery. Continued surgical innovation has seen the recent resurgence of single-port laparoscopic surgery. We present a series of 10 cases of single-incision laparoscopic surgery (SILS) for right hemicolectomy, with the aim of reaffirming the feasibility and favourable short-term results of this technique. METHODS: Ten patients underwent SILS for right hemicolectomy using the SILS port, between June 2009 and August 2009. A longitudinal periumbilical incision was used as the access point for all cases. Data analysed included age, gender, American Society of Anaesthesiology score, body mass index (BMI), location of disease, duration of surgery, length of incision and duration of hospital stay. Inclusion criteria were no prior abdominal surgery, no intra-abdominal sepsis, no distant metastases and a BMI of <30. RESULTS: All 10 cases of right hemicolectomy were successfully performed using the SILS port through a single periumbilical incision. The median age of patients was 64 years (range 48-83 years), with a median body mass index of 21.5 kg/m(2) (range 18.9-25.6 kg/m(2)). The median duration of surgery and hospital stay was 83 min (range 60-125 min) and 6 days (range 5-11 days), respectively. No morbidity or mortality was associated with this technique, and all patients recovered uneventfully. CONCLUSION: This case series illustrates that SILS for right hemicolectomy is feasible and safe. However, the routine use of this innovative technique in malignant disease cannot be recommended without further large-scale prospective trials.

Radiation proctitis: a decade's experience.

INTRODUCTION: Pelvic radiotherapy is an essential component of potentially curative therapy for many pelvic malignancies; however, the rectum consequently often sustains collateral injury. METHODS: The researchers retrieved patient data that was prospectively gathered over a ten-year period between January 1995 and December 2004. The relevant details, including gender, age, pelvic pathology for which radiotherapy was administered, the presenting symptoms, the interval between radiotherapy and the onset of symptoms, the mode of diagnosis, treatments received, length of hospital stay and duration of follow-up, were analysed. RESULTS: During the period under review, 77 patients were admitted for the treatment of radiation proctitis, with a median follow-up period of 14 (range 1-61) months. There were 23 male and 54 female patients, with a median age of 63.9 (range 37-89) years. The most common underlying cancers were gynaecological (63.6 percent), prostate (18.2 percent) and colorectal (15.6 percent) cancer. The most common presenting symptom was bleeding per rectum (89.6 percent), with a change in bowel habits a distant second (10.4 percent). The median latent period between the completion of radiotherapy and the onset of symptoms was 24 (range 3-68) months. The majority of the patients (72.5 percent) received non-surgical treatment, most commonly using topical 4 percent formalin solution to arrest the bleeding, with more than half the patients requiring repeat treatments. 14 (18.2 percent) patients required colorectal resections for intractable bleeding, intestinal obstruction or intra-abdominal sepsis. CONCLUSION: Radiation proctitis can be a therapeutic challenge, even in the most experienced hands. The majority of patients who present with per rectal bleeding can be treated using topical modalities, while surgery may offer the only chance of relief from life-threatening symptoms.

Creation of an intermammary sulcus in congenital synmastia.

Synmastia is a condition where both breasts appear conjoint without an intervening intermammary sulcus. This is usually the result of technical complications during breast implant surgery caused by over-dissection of the medial pocket over the sternum in the subglandular plane, or by an over-division of the pectoralis muscle origin along the sternum in a submuscular plane. As a congenital problem, this is very rare with only a single previous report of an attempt to correct this anomaly. We report a rare case of synmastia in a 19-year-old Indian woman. She had no previous surgery or family history of the condition. Vertical-scar reduction mammoplasty was performed for the hypertrophic breasts. Using the same access, the synmastia was corrected. This approach avoided incisions on the sternum, which is one of the keloid-prone sites on the body. Eight months postoperation, the intermammary sulcus was maintained.

Primary colorectal lymphomas.

OBJECTIVE: The incidence of primary colorectal lymphomas is rare, comprising 10-20% of gastrointestinal lymphomas and only 0.2-0.6% of large bowel malignancies. There is a male predominance, with a maximal reported incidence in the 50- to 70-year age group. Patients often present delayed with nonspecific symptoms and consequently have advanced disease at the time of diagnosis. Inflammatory bowel disease and immunosuppression have been reported as risk factors, although a direct causal link has yet to be established. Treatment often involves a multimodality approach, combining surgery and chemotherapy, with the use of radiotherapy in selected cases. We present our experience in the management of primary colorectal lymphomas over a 10-year period (1989-1999). PATIENTS AND METHODS: We reviewed all cases of primary colorectal lymphoma seen at our institution from 1989 to 1999. Patients were included based on standard diagnostic criteria for primary intestinal lymphoma established by Dawson in 1961. The following clinical information was obtained: age, sex, presentation, site of tumour, operation performed, histology, length of stay, intraoperative complications, adjuvant therapy and duration of follow-up. The type of lymphoma was classified according to the WHO classification system. For staging, a modification of the Ann Arbor system for gastrointestinal lymphoma, proposed by Musshoff, was used. RESULTS: During the 10-year period from 1989 to 1999, 14 cases of primary colorectal lymphomas were identified. This comprised 0.44% of all colorectal malignancies (14 of 3199 cases) seen in our department during this period. There were 13 men and one woman. Their mean age at presentation was 61 years. The common presentations included a combination of abdominal pain (71.4%), anorexia and loss of weight (42.9%) and an abdominal mass (28.6%). The two most common sites of involvement were the caecum (57.1%) and the rectum/sigmoid colon (21.4%). The lesions manifested in a variety of ways, ranging from solitary fungating masses to multiple colonic polyps. All but one patient underwent attempted curative surgical resection. All cases were non-Hodgkin's B-cell lymphomas, with a majority being diffuse large B-cell lymphomas (57.1%). The diagnoses were established through laparotomy in all cases. All cases presented with evidence of spread to regional lymph nodes or beyond. Eleven patients (78.6%) received postoperative chemotherapy, with a regimen that included cyclophosphamide, vincristine, doxorubicin and prednisone. The remaining three were too ill or refused. There were no mortalities within 30 days of surgery. The patients were followed up for a median of 20 months (range 2-84) and more than half are alive and continue to be on follow-up with no evidence of recurrence. CONCLUSION: Primary colorectal lymphoma is a rare condition. It predominantly affects males between the sixth and seventh decade of life and most commonly occurs in the caecum. It often presents with abdominal pain and loss of weight and due to the nonspecific nature of these symptoms, patients frequently present late with advanced loco-regional disease. The histology is usually B cell and of intermediate grade. Therapy usually involves resection of the affected colon and regional lymphovascular structures, followed by adjuvant chemotherapy, with a reported 5-year survival of 27-55%.