Management of colovesical and colovaginal diverticular fistulas Our experience and literature reviewed

AIM

This study aims evaluate the effectiveness of various surgical techniques in treating diverticular fistulas, and the safety and efficacy of the laparoscopic procedure comparing our results with those of the literature.

MATERIAL OF STUDY

This was a prospective and uncontrolled study performed at a general surgery units. Between 2005 and 2011, 16 patients (11 men, 5 women) underwent surgery for diverticular fistulas. The mean age was 70.2 (range, 35-87) years. The medical evaluation of these patients was based on symptoms and diagnostic procedures confirming the diagnosis of diverticular fistulas. Our surgical options included one-stage, two-stage, and defunctioning procedures.

RESULTS

Out of 16 cases of diverticular fistula 14 were colovesical and 2 colovaginal. One-stage procedure was performed in 12 patients, two-stage procedure in 3 and defunctioning colostomy in 1. The overall complication rate was 31.2%. We recorded 1 colovesical recurrent fistula. The laparoscopic surgery was performed in 4 patients, nobody was converted to open and there were no post-operative complications and recurrence.

DISCUSSION AND CONCLUSIONS

The data show that one-stage procedure is effective in the majority of cases of diverticular fistulas. However, the surgery of colovesical and colovaginal fistulas is often associated to high complication rates. This is often due to the shoddy clinical conditions and long-term diverticular illness of this group of patients. At present, the laparoscopy in an elective setting is not considered any more a contraindication in the treatment of diverticular fistulas.

KEY WORDS

Diverticular fistulas, Laparoscopic surgery.

Surgery in MEN 2A Patients Older Than 5 Years with Micro-MTC

In multiple endocrine neoplasia syndrome type 2A (MEN 2A), early total thyroidectomy (TT; performed before the age of 5 years) is the best option to prevent medullary thyroid carcinoma (MTC) development, but the management of MEN 2A patients diagnosed after childhood is still under debate. Seventeen consecutive patients diagnosed with MEN 2A after the age of 5 years (mean age, 23.3 years) with a pathologic diagnosis of micro-MTC without nodal involvement were enrolled. All patients underwent TT with thymectomy and central compartment lymph node dissection. During surgery, parathyroid tissue removal occurred in 14 patients. No major postoperative complications nor persistent hypoparathyroidism was observed. After a mean follow-up of 16.6 years, no patient developed primary hyperparathyroidism or disease recurrence. Even if TT is recommended before the age of 5, when MEN 2A diagnosis is performed after this age in micro-MTC without nodal involvement, TT with thymectomy and central compartment lymphadenectomy can provide good oncologic and functional results.

Oxidative state and IL-6 production in intestinal myofibroblasts of Crohn's disease patients

BACKGROUND

Intestinal subepithelial myofibroblasts (ISEMFs) produce inflammatory cytokines in response to certain stimuli. In the intestine of patients with Crohn's disease (CD), cytokine synthesis is modified and an increased number of myofibroblasts has been observed. The intracellular redox state influences cytokine production and oxidative stress is present in the intestinal mucosa of CD patients.

METHODS

This study was performed in ISEMFs isolated from the colon of patients with active CD and in a myofibroblast cell line derived from human colonic mucosa: 18Co cells. Cellular glutathione (GSH) levels were modulated by treatment with buthionine sulfoximine, an inhibitor of GSH synthesis, or N-acetylcysteine, a GSH precursor. GSH and oxidized glutathione (GSSG) levels were measured by high-performance liquid chromatography (HPLC) methods. Interleukin (IL)-6 production was detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

ISEMFs of CD patients exhibited an increased oxidative state due to a decrease in the GSH/GSSG ratio, which is related to an increase in basal IL-6 production or is stimulated by tumor necrosis factor alpha (TNFα) or bacterial products. This relationship was also confirmed in 18Co cells. Phosphorylation and activation of ERK1/2 and p38 MAPK, which are signaling factors involved in the IL-6 synthesis, were also increased when there is oxidative stress in ISEMFs.

CONCLUSIONS

This study shows for the first time in ISEMFs of CD patients an increased production of IL-6 synthesis related to the decrease in the GSH/GSSH ratio, suggesting redox regulation with the involvement of specific kinase activation. The present data shed light on the pathogenesis of inflammatory chronic processes and relapses that occur in this pathology.

Apoptosis and Bax, Bcl-2, Mcl-1 expression in neutrophils of Crohn's disease patients

BACKGROUND

The etiology of Crohn's disease (CD) remains unknown, and the defective function of neutrophils appears to be associated with this pathology. Neutrophils undergo spontaneous apoptosis which, if not tightly regulated, can induce the development of chronic inflammatory disease. The Bcl-2 protein family is also involved in the regulation of neutrophil apoptosis.

METHODS

This study investigated the apoptosis and expression of some regulatory factors in CD patient and control polymorphonuclear neutrophils (PMN) in suspension and in adhesion on fibronectin, an extracellular matrix protein. These 2 conditions mimic circulating neutrophils before they are recruited at the intestinal levels, and their adhesion to tissue.

RESULTS

Apoptosis in CD patient PMN was delayed in suspension and accelerated in adhesion, which is the opposite of what happens in controls. Higher levels of Bax, Bcl-2, and Mcl-1 proteins were registered in freshly isolated CD patient PMN, in contrast to controls, in which Bcl-2 protein was undetectable. Among the studied pro- and antiapoptotic factors, Bax levels seem to be mainly related to the difference in apoptosis between PMN of CD patients and controls.

CONCLUSIONS

For the first time it has been demonstrated by direct experimental evidence that apoptosis in CD patient PMN is regulated differently from that of control PMN. Abnormal expression of regulating apoptosis proteins is shown in CD patient PMN. These data suggest that the defective functionality of neutrophils can be the early event responsible for the altered mucosal immune response in CD, and that neutrophil apoptosis may offer a new target for specific drugs and therapy tools.

Somatostatinoma: clinico-pathological features of three cases and literature reviewed

Somatostatinoma is a rare endocrine tumor that comprises around 1% of all gastroenteropancreatic endocrine neoplasms. This paper gives an updated review on somatostatinoma and describes three sporadic cases of somatostatinoma located in the pancreas, duodenum, and jejunum. Approximately 200 case histories of somatostatinoma have been published, with the duodenum being the most frequent site, followed by the pancreas. Somatostatinomas may be sporadic or associated with neurofibromatosis type 1, Multiple Endocrine Neoplasia type 1, and Von Hippel-Lindau syndromes. Functional somatostatinomas release excessive amounts of somatostatin suppressing gallbladder motility and inhibiting the secretory activity of various endocrine and exocrine cell types. A triad of mild diabetes mellitus, cholelithiasis, and diarrhea/steatorrhoea characterizes the somatostatinoma or 'inhibitory' syndrome. Non-functional somatostatinomas tend either to be asymptomatic or to present with obstructive symptoms. These tumors are often malignant and by the time they are detected, nearly two-thirds have already metastasized to the regional lymph nodes or the liver. A comparison between our three cases and those in the literature provides useful insights into the clinical management of these patients. Interestingly, the jejunal somatostatinoma described here is the second case ever reported.

Redox state and O2*- production in neutrophils of Crohn's disease patients

The aim of this in vitro study was to evaluate the intracellular redox state and respiratory burst (RB) in neutrophils of patients with Crohn's disease (CD). The intracellular redox state and RB in neutrophils was assessed by the superoxide anion (O2*-) production induced in these cells after stimulation by various factors related to the molecular mechanisms that, if altered, may be responsible for an abnormal immune response. This can, in part, cause the onset of inflammation and tissue damage seen in CD. This study demonstrated a decreased glutathione/glutathione disulfide (GSH/GSSG) ratio index of an increased oxidative state in CD patient neutrophils. Moreover, our findings showed a decrease in tumor necrosis factor (TNF-alpha)- or phorbol 12-myristate 13-acetate (PMA)-induced O2*- production in CD patient neutrophils adherent to fibronectin as compared with controls. A decreased adhesion was also demonstrated. For this reason, the involvement of altered mechanisms of protein kinase C (PKC) and beta-integrin activation in CD patient neutrophils is suggested. These data also showed that the harmful effects of TNF-alpha cannot be caused by excessive reactive oxygen species (ROS) production induced by neutrophils. Decreased cell viability after a prolonged time of adhesion (20 hrs) was also measured in CD patient neutrophils. The findings of this study demonstrate, for the first time, that granulocyte-macrophage colony-stimulating factor (GM-CSF), a compound recently used in CD therapy, is able to activate the RB for a prolonged time both in control and CD patient neutrophils. Increased viability of CD patient neutrophils caused by GM-CSF stimulation was also observed. In conclusion, our results indicate that decreased O2*- production and adhesion, caused, in part, by an anomalous response to TNF-alpha, together with low GSH level and low cell viability, may be responsible for the defective neutrophil function found in CD patients. This can contribute to the chronic inflammation and relapses that characterize this pathology. A possible role of GM-CSF in inducing O2*- production and in restoring the defensive role of neutrophils in CD patients is suggested.

Characterization of the functional and growth properties of long-term cell cultures established from a human somatostatinoma

In somatostatinoma, a rare malignant somatostatin (SST)-secreting neoplasia, tumour regression is rarely observed, implying the need for novel antiproliferative strategies. Here, we characterized a long-term culture (SST-secreting cancer (SS-C cells)) established from a human somatostatinoma. High concentrations of SST and chromogranin A were released by SS-C cells and SST release was stimulated by depolarizing stimuli and inhibited by the SST analogue, octreotide. SS-C cells expressed mRNA for SST receptor (SSTR) subtypes 1, 2 and 4, being also able to bind native SST. Moreover, SS-C cells were positively stained with an antibody to SSTR2. SS-C cells also expressed interferon-gamma (IFN-gamma) receptor mRNA and measurable telomerase activity. Our findings indicate that in vitro exposure of SS-C cells to native SST-28, to octreotide, to IFN-gamma, or to 3'-azido-3'deoxythymidine (AZT), a telomerase inhibitor, results in inhibition of SS-C cell proliferation. Concomitant with growth inhibition, apoptosis was detected in SST-, octreotide-, IFN-gamma- or AZT-treated SS-C cell cultures. Taken together our results characterized native SST, SST analogues, IFN-gamma and a telomerase inhibitor as growth-inhibiting and proapoptotic stimuli in cultured human somatostatinoma cells. Based on these findings, the potential of SST analogues, IFN-gamma and AZT, alone or in combination, should be further explored in the medical treatment of somatostatinoma.

Redox regulation of platelet-derived-growth-factor-receptor: Role of NADPH-oxidase and c-Src tyrosine kinase

This study identifies some early events contributing to the redox regulation of platelet-derived growth factor receptor (PDGFr) activation and its signalling in NIH3T3 fibroblasts. We demonstrate for the first time that the redox regulation of PDGFr tyrosine autophosphorylation and its signalling are related to NADPH oxidase activity through protein kinase C (PKC) and phosphoinositide-3-kinase (PI3K) activation and H2O2 production. This event is also essential for complete PDGF-induced activation of c-Src kinase by Tyr416 phosphorylation, and the involvement of c-Src kinase on H2O2-induced PDGFr tyrosine phosphorylation is demonstrated, suggesting a role of this kinase on the redox regulation of PDGFr activation. Finally, it has been determined that not only PI3K activity, but also PKC activity, are related to NADPH oxidase activation due to PDGF stimulation in NIH3T3 cells, as it occurs in non-phagocyte cells. Therefore, we suggest a redox circuit whereby, upon PDGF stimulation, PKC, PI3K and NADPH oxidase activity contribute to complete c-Src kinase activation, thus promoting maximal phosphorylation and activation of PDGFr tyrosine phosphorylation.

[Rectal cancer: locoregional recurrence in relation to surgical and complementary treatment]

Much recent data have been published on the risk of local recurrence (LR) following curative surgery for rectal cancer and the impact of adjuvant therapy. On the other hand, improvements in surgical techniques, as the total mesorectal excision, have apparently reduced the risk of LR. Furthermore, in selected cases, neoadjuvant therapy seems to reduce much more the incidence of LR. A list of prognostic factors which affect the onset of LR, other than the different procedures, was considered. To investigate such evidences a retrospective analysis was undertaken in our series, focusing on examination of the employed techniques as potential predictors of local recurrence. Thus, in a 18-yr-period (1986-2003), two hundred and ninety-five patients who had undergone elective curative surgical resection of rectal cancer were included in the study. The demographic, operative and follow-up data were collected retrospectively. All patients underwent total mesorectal excision, whereas neoadjuvant therapy was performed in a selected series of patients, according to defined entry criteria patterns. Results evidenced LR in 7.1% of patients and occurred between 6 months to 8 year following surgery. Comparisons were made between patients who had different surgical procedures; indeed sphyncter saving procedures correlated with a higher incidence of LR rather than abdomino-perineal resection. Pelvic recurrences were observed more frequently compared to the anastomotic ones. A limited number of patients with LR underwent surgery due to the associated condition of metastatic lesions; the follow-up related to such series evidenced a mortality rate of 57% within 3 year from reoperation. A low local recurrence rate can be achieved after total mesorectal excision (TME) without preoperative radiotherapy. Our results suggest that preoperative radiotherapy may be employed only for those patients who are at a higher risk for local recurrence.

The rational principles of neo-adjuvant therapy for rectal cancer

BACKGROUND

Aim of the study is to analyze rational principles which at present govern the neoadjuvant therapy for rectal cancer and justify his application. First step is definition of targets: cellular replication block, volumetric reduction of rectal cancer, mesorectum and lateral nodes (Down staging), reduction of side-effects on close organs, radiation on more limited tissue volumes, major series of sphincter saving procedures, minor risk of microscopic tumour deposits. Second step regards standards which Protocols strive in order to: patients selection, therapeutic index, restaging before surgery, total mesorectal excision (TME). Further step accounts for evidence of drawbacks, related to Neoadjuvant approach, both Radiotherapy alone (RT) or Radiochemotherapy (CH-RT).

METHODS

Indications for neoadjuvant therapy, basing a difference between the absolute and relative one, are explained. Given that granting role to such therapy still now remain partially unclear, we have outlined the following topics: A) survey of main protocols is managed, taking care on dose/response ratio, focusing on enhanced supply for fixed tumours, checking on a list of several drugs (oxaliplatinum, capecitabin, raltitrexed, CPT-11, eniluracil), which are medicated with RT and furthermore on a list of substitute RT methods (HART, IORT, Endocavitary). B) following whole treatments, according such a different approaches, analysis of obtained outcomes in the literature are carried out. C) Personal experience, basing on a previous series where Down-staging has been sought, comparing indicatively clinical and diagnostic data before neoadjuvant therapy and before surgery. D) List of open issues, not solved at present, is shown

CONCLUSIONS

Neoadjuvant therapy may be considered a rational approach for treatment of curative rectal cancer; indeed, preliminary results seem to introduce a real advantage compared to adjuvant therapy, even if is mandatory to associate proper surgical procedure, as TME, to warrant low local recurrences. Targets, related to such therapy, may be noticed ideal even though outcomes don't come up always to statements. So, continuous efforts to ameliorate rates of free-disease series, as well mortality rates and toxical effects are advised.