Benefits of povidone-iodine solution in colorectal operations: science or legend

Self-Assembling Imageable Silk Hydrogels for the Focal Treatment of Osteosarcoma

Background: The standard treatment for osteosarcoma comprises complete surgical resection and neoadjuvant chemotherapy, which may cause serious side effects and partial or total limb loss. Therefore, to avoid the disadvantages of traditional treatment, we developed self-assembling imageable silk hydrogels for osteosarcoma.

Methods: We analysed whether iodine induced apoptosis in MG-63 and Saos-2 cells by using CCK-8 and flow cytometry assays and transmission electron microscopy. Western blotting was used to analyse the pathway of iodine-induced apoptosis in osteosarcoma cells. PEG400, silk fibroin solution, polyvinylpyrrolidone iodine (PVP-I), and meglumine diatrizoate (MD) were mixed to produce an imageable hydrogel. A nude mouse model of osteosarcoma was established, and the hydrogel was injected locally into the interior of the osteosarcoma with X-ray guidance. The therapeutic effect and biosafety of the hydrogel were evaluated.

Results: Iodine treatment at 18 and 20 µM for 12 h resulted in cell survival rate reduced to 50 ± 2.1% and 50.5 ± 2.7% for MG-63 and Sao-2 cells, respectively (p < 0.01). The proportion of apoptotic cells was significantly higher in the iodine-treatment group than in the control group (p < 0.05), and apoptotic bodies were observed by transmission electron microscopy. Iodine could regulate the death receptor pathway and induce MG-63 and Saos-2 cell apoptosis. The hydrogels were simple to assemble, and gels could be formed within 38 min. A force of less than 50 N was required to inject the gels with a syringe. The hydrogels were readily loaded and led to sustained iodine release over 1 week. The osteosarcoma volume in the PEG-iodine-silk/MD hydrogel group was significantly smaller than that in the other three groups (p < 0.001). Caspase-3 and poly (ADP-ribose) polymerase (PARP) expression levels were significantly higher in the PEG-iodine-silk/MD hydrogel group than in the other three groups (p < 0.001). Haematoxylin and eosin (H&E) staining showed no abnormalities in the heart, liver, spleen, lung, kidney, pancreas or thyroid in any group.

Conclusions: Self-assembling imageable silk hydrogels could be injected locally into osteosarcoma tissues with X-ray assistance. With the advantages of good biosafety, low systemic toxicity and minimal invasiveness, self-assembling imageable silk hydrogels provide a promising approach for improving the locoregional control of osteosarcoma.

The influence of intraoperative rectal washout on local recurrence of colorectal cancer following curative resection: a systematic review and meta-analysis

PURPOSE

To determine the effectiveness of rectal washout in preventing local recurrence of distal colorectal cancer following curative resection.

METHODS

A systematic review and meta-analysis was performed after a literature search was conducted on MEDLINE, EMBASE, the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), ClinicalTrials.gov, and the ISRCTN registry. The study was reported using PRISMA guidelines. The primary endpoint was incidence of local recurrence of cancer after distal colonic and rectal cancer surgery.

RESULTS

After screening, 8 studies with a total sample size of 6739 patients were identified. At 5-year follow-up, local recurrence in the washout group (WO) was 6.08% compared to 9.48% in the no-washout group (NWO) group (OR 0.63, 95% CI = 0.51-0.78, Chi² = 6.76, df = 7, p = 0.45). The relative risk reduction was 36.9%. To exclude a 36.9% relative risk reduction from 9.48 to 6.08% with a 5% significance level and 80% power a randomized control trial would require a total sample size of 1946 participants distributed equally between the two treatment arms.

CONCLUSION

It is safe to recommend the use of rectal washout for left sided and rectal tumour resections. It is a simple and safe step during colorectal surgery that appears to improve long-term oncological outcomes and was not reported to be associated with any complications.

Peritoneal lavage with povidone-iodine solution in colorectal cancer-induced rats

BACKGROUND

Although peritoneal lavage with povidone-iodine (PVPI) is frequently performed after surgery on the gastrointestinal tract, the effects of PVPI on the intestinal epithelial barrier are unknown. The purpose of this study was to investigate the effects of abdominal irrigation with PVPI on the intestinal epithelial barrier in a colorectal cancer (CRC)-induced rat model.

MATERIALS AND METHODS

The CRC model was induced in rats with azoxymethane and dextran sodium sulfate. Next, a total of 24 male CRC-induced rats were randomly divided into three groups (n = 8): (1) a sham-operated group, (2) an NS group (peritoneal lavage 0.9% NaCl), and (3) a PVPI group (peritoneal lavage with 0.45%-0.55% PVPI). The mean arterial pressure was continuously monitored throughout the experiment. The levels of plasma endotoxin and D-lactate, blood gases, and protein concentration were measured. The ultrastructural changes of the epithelial tight junctions were observed by transmission electron microscopy.

RESULTS

The mean arterial pressure after peritoneal lavage was lower in the PVPI group than that in the NS group. The protein concentration and levels of endotoxin and D-lactate were higher in the PVPI group than they were in the PVPI group. In addition, PVPI treatment resulted in a markedly severe metabolic acidosis and intestinal mucosal injury compared with NS rats.

CONCLUSIONS

Peritoneal lavage with PVPI dramatically compromises the integrity of the intestinal mucosa barrier and causes endotoxin shock in CRC rats. It is unsafe for clinical applications to include peritoneal lavage with PVPI in colorectal operations.

Surgical stress response and promotion of metastasis in colorectal cancer: a complex and heterogeneous process

Surgery remains the curative treatment modality for colorectal cancer in all stages, including stage IV with resectable liver metastasis. There is emerging evidence that the stress response caused by surgery as well as other perioperative therapies such as anesthesia and analgesia may promote growth of pre-existing micro-metastasis or potentially initiate tumor dissemination. Therapeutically targeting the perioperative period may therefore reduce the effect that surgical treatments have in promoting metastases, for example by combining β-adrenergic receptor antagonists and cyclooxygenase-2 (COX-2) inhibitors in the perioperative setting. In this paper, we highlight some of the mechanisms that may underlie surgery-related metastatic development in colorectal cancer. These include direct tumor spillage at the time of surgery, suppression of the anti-tumor immune response, direct stimulatory effects on tumor cells, and activation of the coagulation system. We summarize in more detail results that support a role for catecholamines as major drivers of the pro-metastatic effect induced by the surgical stress response, predominantly through activation of β-adrenergic signaling. Additionally, we argue that an improved understanding of surgical stress-induced dissemination, and more specifically whether it impacts on the level and nature of heterogeneity within residual tumor cells, would contribute to the successful clinical targeting of this process. Finally, we provide a proof-of-concept demonstration that ex-vivo analyses of colorectal cancer patient-derived samples using RGB-labeling technology can provide important insights into the heterogeneous sensitivity of tumor cells to stress signals. This suggests that intra-tumor heterogeneity is likely to influence the efficacy of perioperative β-adrenergic receptor and COX-2 inhibition, and that ex-vivo characterization of heterogeneous stress response in tumor samples can synergize with other models to optimize perioperative treatments and further improve outcome in colorectal and other solid cancers.

Prostate Biopsy-related Infection: A Systematic Review of Risk Factors, Prevention Strategies, and Management Approaches

A systematic review to identify risk factors for prostate biopsy-related infection, preventative strategies, and optimal management of infectious complications was conducted. Significant risk factors for postbiopsy infection include urogenital infection, antibiotic use, international travel, hospital exposure, bacteriuria, previous transrectal biopsy, and resistance of fecal flora to antibiotic prophylaxis (especially fluoroquinolones). Patients at risk may benefit from an adjusted biopsy protocol comprising transrectal biopsy under targeted prophylaxis, and/or the use of rectal disinfection techniques or using a transperineal approach. Management of biopsy-related infection should be based on individual risk and local resistance profiles with input from multiple specialties.

Intra-operative wound irrigation to reduce surgical site infections after abdominal surgery: a systematic review and meta-analysis

PURPOSE

Surgical site infection (SSI) remains to be one of the most frequent infectious complications following abdominal surgery. Prophylactic intra-operative wound irrigation (IOWI) before skin closure has been proposed to reduce bacterial wound contamination and the risk of SSI. However, current recommendations on its use are conflicting especially concerning antibiotic and antiseptic solutions because of their potential tissue toxicity and enhancement of bacterial drug resistances.

METHODS

To analyze the existing evidence for the effect of IOWI with topical antibiotics, povidone-iodine (PVP-I) solutions or saline on the incidence of SSI following open abdominal surgery, a systematic review and meta-analysis of randomized controlled trials (RCTs) was carried out according to the recommendations of the Cochrane Collaboration.

RESULTS

Forty-one RCTs reporting primary data of over 9000 patients were analyzed. Meta-analysis on the effect of IOWI with any solution compared to no irrigation revealed a significant benefit in the reduction of SSI rates (OR = 0.54, 95 % confidence Interval (CI) [0.42; 0.69], p < 0.0001). Subgroup analyses showed that this effect was strongest in colorectal surgery and that IOWI with antibiotic solutions had a stronger effect than irrigation with PVP-I or saline. However, all of the included trials were at considerable risk of bias according to the quality assessment.

CONCLUSION

These results suggest that IOWI before skin closure represents a pragmatic and economical approach to reduce postoperative SSI after abdominal surgery and that antibiotic solutions seem to be more effective than PVP-I solutions or simple saline, and it might be worth to re-evaluate their use for specific indications.

Risk factors for surgical site infection in emergency colorectal surgery: a retrospective analysis

BACKGROUND

Since 2005, we have been conducting prospective surgical site infection (SSI) surveillance and infection control according to the U.S. Centers for Disease Control and Prevention guidelines for patients who undergo gastrointestinal surgery at our institution. Surgical site infection occurs with greater frequency in emergency than in elective surgery because of factors such as ill-conceived preoperative preparation and "dirty" operations. A large number of studies have been reported on risk factors for SSI in elective colorectal surgery; however, there are few papers on such factors in emergency colorectal surgery. The aim of this study was to identify risk factors for incisional SSI in emergency colorectal surgery.

METHODS

Using our SSI surveillance database, we analyzed retrospectively 78 patients who underwent emergency colorectal surgery between 2005 and 2010. Univariable and multivariable analyses were used to identify risk factors for incisional SSI. Moreover, we subclassified dirty-infected operations (class IV) by the extent of contamination according to our own definition to study the incidence of incisional SSI at each degree.

RESULTS

The incidence of incisional SSI was 32.1% (25/78 patients). By univariable analysis, seven parameters correlated with a higher risk of incisional SSI: Surgical incision class III-IV, obesity (body mass index ≥25 kg/m(2)), American Society of Anesthesiologists score 3 or 4 points, chronic kidney disease (serum creatinine concentration >1.2 mg/dL), blood loss ≥200 mL, blood transfusion, and ventilator support. Multivariable analyses showed that surgical incision class III-IV (odds ratio [OR] 5.9; 95% confidence interval [CI] 1.7, 25.2) and obesity (OR 11.9; 95% CI 2.1, 87.8) were independent risk factors for incisional SSI. The incidence of incisional SSI in colon perforation with generalized contamination was statistically higher than that in prepared colon perforation and colon perforation with localized contamination (82.4% vs. 25.0%; p<0.001).

CONCLUSIONS

The risk factors for incisional SSI in emergency colorectal surgery were incision contamination and obesity. Moreover, the incidence of incisional SSI among the incision class IV operations increased significantly with increasing extents of contamination. As a tactic for management of dirty abdominal wounds, we suggest that primary skin closure is suitable in cases of perforation of a prepared colon or colon perforation with localized contamination. On the other hand, in cases of colon perforation with generalized contamination, delayed primary skin closure or leaving an incision open to heal by secondary intention should be considered.

Benefits of the povidone-iodine: simultaneously decrease risk of infection and tumor seeding after percutaneous endoscopic gastrostomy

Percutaneous endoscopic gastrostomy (PEG) is a well-established enteral feeding modality in patients with oropharyngeal/esophageal cancer; however, these patients are at risk for two possible PEG-related complications. First, oropharyngeal organisms may be transported to the PEG stoma and thus increase the risk of peristomal infection. Second, oropharyngeal/esophageal cancer cells may adhere to the PEG tube and thus increase the risk of tumor seeding along the PEG tract. Because of its microbicidal and tumoricidal effects, povidone-iodine pretreatment of the PEG tube may decrease the risk of peristomal infection and tumor seeding associated with PEG insertion in patients with oropharyngeal/esophageal cancer. To test this hypothesis, we brushed povidone-iodine onto the outer surface of PEG tubes prior to insertion.

Recurrent breast cancer in the subpectoral space after implant reconstruction

Breast reconstruction after mastectomy is most commonly performed with a prosthetic implant placed beneath the pectoralis major. Recurrence may rarely be identified in the subpectoral space where the implant was placed. We report a case of recurrent breast cancer after implant-based reconstruction with isolated subpectoral recurrence discovered 5 years later during secondary revision of her reconstructed breast.

Rectosigmoid stump washout as an alternative to permanent mucous fistula in patients undergoing subtotal colectomy for ulcerative colitis in emergency settings

Background

Restorative proctocolectomy with ileopouch-anal anastomosis (IPAA) is the treatment of choice for intractable or complicated ulcerative colitis(UC). Elderly patients often present with acute colitis requiring emergent subtotal colectomy(SC). Frail patients are at risk of developing septic complications related to the closed rectosigmoidal stump, often requiring formation of a second stoma to be reversed at the time of completion proctectomy. This carries nuisance to such exhausted patients. We propose a simple and inexpensive trick to avoid the need for creating a mucous fistula.

Methods

IPAA was performed as a 3-stage procedure in emergency settings. The rectosigmoidal stump was closed and placed subcutaneously; skin was closed over it. After SC, if patients showed signs of stump-related pelvic sepsis, a lavage of the rectal stump with povidone iodine solution and with saline was carried out as a rescue treatment aiming to avoid the need of opening the rectal stump to drain sepsis.

Results

Thirty-five patients underwent SC for UC between 1987 and 2012. The skin was closed over the closed stump in the 20. Seven patients out of these 20 experienced early stump-related septic complication. In five cases, we were able to avoid opening of the rectal stump, and a second stoma was unnecessary. After opening the closed stump in the remaining ones, a prompt improving of symptoms was observed.

Conclusions

Rectal washout was well tolerated and avoided a second stoma in five out of seven patients, with better quality of life and body perception after IPAA surgery. This is relevant when dealing with geriatric patients, needing to completely recover before undergoing completion proctectomy.

Rectal washout and local recurrence in rectal resection for cancer: a meta-analysis

AIM

The effectiveness of rectal washout was compared with no washout for the prevention of local recurrence after anterior rectal resection for rectal cancer.

METHOD

The following electronic databases were searched: PubMed, OVID Medline, Cochrane Database of Systematic Reviews, EBM Reviews, CINAHL and EMBASE.

RESULTS

Five nonrandomized studies including a total of 5012 patients were identified. Meta-analysis suggested that rectal washout significantly reduced the local recurrence rate (P < 0.0001; OR 0.57; 95% CI 0.43-0.74). It was also significantly lower after washout in patients having radical resection only (P = 0.0004; OR 0.54; 95% CI 0.39-0.76), patients treated by a curative resection (P < 0.0001; OR 0.55; 95% CI 0.42-0.72) and those undergoing preoperative radiotherapy (P = 0.04; OR 0.62; 95% CI 0.39-0.98).

CONCLUSION

Taking into account the limitations of the design of the included studies the meta-analysis showed that rectal washout is associated with reduced local recurrence and therefore should be routine during anterior resection for rectal cancer.

Selection of irrigation fluid to eradicate free cancer cells during head and neck cancer surgery

BACKGROUND

Free cancer cells can be spilled out from exposed tumors or ruptured tumors. We examined the cytocidal effect of various irrigation fluids on free cancer cells in an animal wound model mimicking head and neck surgery.

METHODS

Cancer cell-contaminated wounds were made with C3H/HeJ mice and syngeneic squamous cell carcinoma (SCC VII) cells. Distilled water, 5% povidone-iodine, 1.5% H(2)O(2), normal saline, and cisplatin were used to irrigate for 5 minutes. In vitro tumor growth assays were done with different concentrations and exposure times of povidone-iodine and distilled water.

RESULTS

In the animal study, povidone-iodine significantly inhibited tumor growth. Povidone-iodine caused substantial inhibition of in vitro tumor growth, even at the concentration of 0.05%. After 30 seconds of exposure to 1% povidone-iodine, cancer cells were completely inhibited.

CONCLUSIONS

Povidone-iodine could be selected preferentially for the irrigation fluid during head and neck surgery, especially when the wound is suspected of cancer cell contamination.

Application of an electrolyzed strongly acidic aqueous solution before wound closure in colorectal surgery

BACKGROUND

Electrolyzed strongly acidic aqueous solution which is produced by electrolysis of a sodium chloride solution has been used in Japan for the irrigation of wounds or body cavities even in the absence of particular evidence.

OBJECTIVE

The purpose of this study is to investigate the efficacy or harmful effects of the disinfectant when applied before wound closure in colorectal surgery.

DESIGN

We performed a prospective, randomized study.

SETTING

The study was conducted at Surgical Department of Hyogo College of Medicine

PATIENTS

Patients who underwent elective colorectal surgery were randomly assigned to 2 groups. The surgical wound was irrigated with >500 mL of the disinfectant or saline solution after the completion of fascia closure. Patients with dirty/infected wounds were excluded from the study.

MAIN OUTCOME MEASURES

The primary end point of this study was comparison of the frequency of incisional surgical site infection. The secondary end point was the occurrence of wound dehiscence or wound hernia.

RESULTS

One hundred eighty patients in the disinfectant group and 183 patients in the saline solution group were analyzed. In multivariate analysis, IBD and contaminated wounds were independent risk factors for incisional surgical site infection. Application of the disinfectant tended to lower the risk of the infection (OR 0.457, 95% CI 0.206-1.013). In the analysis of poor wound healing, preoperative hospital stay of >2 weeks, stoma creation, and use of the disinfectant (OR 2.28, 95% CI 1.03-5.04) were independent risk factors.

LIMITATION

This study was not a double-blind trial.

CONCLUSIONS

Application of electrolyzed strongly acidic aqueous solution to the wound impaired wound healing. Routine use of electrolyzed strongly acidic aqueous solution is not recommended in patients undergoing elective colorectal surgery. As for the contribution of the disinfectant to preventing wound infections, further study is needed to make a definitive conclusion.

Povidone-Iodine Irrigation of Subcutaneous Tissues May Decrease Surgical Site Infections in Elective Colorectal Operations: A Systematic Review

Background

Postoperative wound infection is the most common complication following abdominal surgery and leads to delayed wound healing, prolonged hospital length of stay (LOS), and causes morbidity. Povidone-Iodine (PVI) is a broad-spectrum anti-septic and disinfectant solution, and can be used intra-operatively to irrigate subcutaneous tissues prior to abdominal skin closure. We systematically reviewed the literature regarding the efficacy of intra-operative PVI irrigation of subcutaneous tissues following elective colorectal surgery.

Methods

A comprehensive search of electronic databases and various grey literature sources was completed. Unpublished and non-English-language results were included. All clinical controlled trials involving PVI solution in adult colorectal surgery were included. Two independent reviewers assessed the studies for relevance, inclusion, methodological quality and extracted data from the full versions of the manuscripts. Disagreements were resolved by re-extraction or third party adjudication. Data for dichotomous outcomes are reported as relative risks (RR) with 95% confidence intervals (CI). For continuous data, mean differences (MD) are reported with 95% CIs.

Results

Five randomized controlled trials (RCTs) involving 205 patients comparing PVI solution or spray to a control group following abdominal fascial closure in elective colorectal or clean-contaminated operations were identified. Pooled results demonstrated a reduction in surgical site infection for patients treated with PVI (RR = 1.97; 95% CI: 1.22 to 3.17) compared to controls.

Conclusions

Irrigation of subcutaneous tissues with PVI following abdominal fascial closure is associated with a reduced incidence of surgical site infection. Due to the small number of included trials and patients, additional robust randomized trials are needed.

Water: a simple solution for tumor spillage

BACKGROUND

Although often proposed as a means to reduce the harmful consequences of tumor spill, water lavage has yet to be systematically evaluated in relevant in vitro and in vivo models. This study evaluates the mechanisms and utility of a single water lavage to improve the sequelae of tumor spill during laparotomy.

METHODS

Murine colorectal tumor cell susceptibility to water-induced osmotic lysis was characterized in vitro. A reproducible model of tumor spill was established to recapitulate water or saline lavage during laparotomy. Analyses of tumor volumes calculated from noninvasive imaging were performed. The tumor volumes and survival of mice treated with water, normal saline, or sham laparotomy were assessed.

RESULTS

Significant osmotic lysis of cultured murine colorectal cancer cells was observed after a brief exposure to water. Compared to saline or sham laparotomy, water lavage demonstrated superior clinical outcomes with a decrease in tumor burden and concomitant improvement in survival.

CONCLUSIONS

The use of water lavage during oncologic surgeries to reduce the sequelae of tumor spill is justified and strongly supported by our study. Data from our study raise several concerns regarding the mechanisms and efficacy of saline lavage. Clinically, the use of water lavage during laparotomy would be anticipated to reduce peritoneal disease burden with minimal toxicity or cost.