Sclerosing encapsulating peritonitis after intraperitoneal use of povidone iodine

Peritoneal Dialysis-Induced Encapsulating Peritonitis: Diagnostic and Therapeutic Challenges in Women with Benign Gynecological Pathology

Background: Peritoneal sclerosis (PS) and its most severe form, encapsulating PS (EPS), are rare entities that can occur in various procedures (liver transplantation, intraperitoneal chemotherapy) or secondary to medications (beta-blockers); however, PS or EPS typically occur in patients undergoing peritoneal dialysis as a form of renal function substitution. Medical or surgical treatments can be applied, but morbidity and mortality have high rates. This condition typically presents clinically as an intestinal obstruction caused by the inclusion of the intestinal loops in the peritoneal fibrous membrane. Methods: Herein, we present data from a single tertiary surgery center that has dedicated teams for patients receiving dialysis. Over 12 years, we analyzed a group of 63 patients admitted for catheter replacement/removal or for acute surgical pathology. In five cases (7.9%), we diagnosed EPS. Two patients with EPS presented with atypical abdominal pathologies requiring emergency surgery: one case of hemoperitoneum caused by a ruptured ovarian cyst and one case of uterine fibroids and metrorrhagia. Results: The definitive diagnoses were established intraoperatively and by analyzing the morpho-pathological changes in the peritoneum. The possible intraoperative challenges included laborious dissection, difficulties in restoring the correct anatomical landmarks, an increased duration of the surgical intervention and a high rate of incidents and accidents. Conclusions: The aim of the present study was to emphasize the possibility of other surgical pathologies overlapping with EPS, increasing the complexity of the surgical intervention.

Intraoperative Use of Betadine Irrigation is Associated With a 9-Fold Increased Likelihood of Penile Prosthesis Infection: Results From a Retrospective Case-Control Study

Introduction

Infection remains a persistent complication of penile prosthesis (PP) surgery. Despite popularity of Mulcahy’s PP washout protocol, Betadine has known tissue toxicity.

Aim

We evaluated PP infection rate based on the type of intraoperative irrigation used, ½ strength Betadine vs vancomycin/gentamicin.

Methods

We reviewed a prospective database of men undergoing primary, revision, and salvage PPs. No other changes to operative or perioperative techniques occurred after the change in irrigation solution. Univariate and logistic regression analyses were used to evaluate differences in infection rate with use of Betadine vs vancomycin/gentamicin irrigation. Potential confounders were reviewed.

Main Outcome Measure

The primary outcome was rate of PP infection before and after change of intraoperative irrigation.

Results

From 2014 to 2018, 217 patients underwent PP placement at our institution by a single surgeon; of whom, 21 (9.7%) experienced an infection (primary = 10 [7.1%], revision = 11 [17.19%], salvage = 0 [0%]). Overall, 152 (70%) received irrigation with Betadine and 65 (30%) with Vancomycin/Gentamicin. Univariate analysis demonstrated significantly increased infection rates with Betadine irrigation (odds ratio [OR]: 4.64, P = .006) and with revision surgery (OR: 2.68, P = .02). Significance of increased infection rate with Betadine was maintained (OR: 9.3; P = .025) after controlling for age, body mass index, Charlson comorbidity index, smoking, diabetes, primary vs revision/salvage, prior penile surgery, use of ectopic reservoir, and adjunctive glanulopexy.

Conclusions

Changing from intraoperative Betadine to vancomycin/gentamicin solution dramatically reduced infection rates among men undergoing PP placement in both primary and revision cases. We hypothesize that differences in infection rate may relate to the relative toxicity or non-sterile nature of Betadine.

Manka MG, Yang D, Andrews J, et al. Intraoperative Use of Betadine Irrigation is Associated With a 9-Fold Increased Likelihood of Penile Prosthesis Infection: Results From a Retrospective Case-Control Study. Sex Med 2020;8:422–427.

Recommendations on the Management of Encapsulating Peritoneal Sclerosis in Japan, 2005: Diagnosis, Predictive Markers, Treatment, and Preventive Measures

This comprehensive update on the management of encapsulating peritoneal sclerosis incorporates insights gained from recently published findings and the accumulated experience of the authors. Aspects covered include diagnosis, risk factors and predictive markers, treatment, and prevention, including criteria for withdrawal from peritoneal dialysis.

Encapsulating Peritoneal Sclerosis: Pathophysiology and Current Treatment Options

Encapsulating peritoneal sclerosis (EPS) is a life-threatening complication of long-term peritoneal dialysis (PD), which may even occur after patients have switched to hemodialysis (HD) or undergone kidney transplantation. The incidence of EPS varies across the globe and increases with PD vintage. Causative factors are the chronic exposure to bioincompatible PD solutions, which cause long-term modifications of the peritoneum, a high peritoneal transporter status involving high glucose concentrations, peritonitis episodes, and smoldering peritoneal inflammation. Additional potential causes are predisposing genetic factors and some medications. Clinical symptoms comprise signs of intestinal obstruction and a high peritoneal transporter status with incipient ultrafiltration failure. In radiological, macro-, and microscopic studies, a massively fibrotic and calcified peritoneum enclosed the intestine and parietal wall in such cases. Empirical treatments commonly used are corticosteroids and tamoxifen, which has fibrinolytic properties. Immunosuppressants like azathioprine, mycophenolate mofetil, or mTOR inhibitors may also help with reducing inflammation, fibrin deposition, and collagen synthesis and maturation. In animal studies, N-acetylcysteine, colchicine, rosiglitazone, thalidomide, and renin-angiotensin system (RAS) inhibitors yielded promising results. Surgical treatment has mainly been performed in severe cases of intestinal obstruction, with varying results. Mortality rates are still 25–55% in adults and about 14% in children. To reduce the incidence of EPS and improve the outcome of this devastating complication of chronic PD, vigorous consideration of the risk factors, early diagnosis, and timely discontinuation of PD and therapeutic interventions are mandatory, even though these are merely based on empirical evidence.

Encapsulating Peritoneal Sclerosis: The Abdominal Cocoon

Encapsulating peritoneal sclerosis (EPS) is a rare but serious condition that results in (a) encapsulation of bowel within a thickened fibrocollagenous peritoneal membrane and (b) recurrent episodes of bowel obstruction. Although described by various names in the literature, the preferred term is encapsulating peritoneal sclerosis because it best describes the morphologic and histologic changes in this disorder. The etiology of EPS is multifactorial, with a wide variety of implicated predisposing factors that disrupt the normal physiologic function of the peritoneal membrane-prime among these factors being long-term peritoneal dialysis and bacterial peritoneal infections, especially tuberculosis. The clinical features of EPS are usually nonspecific, and knowledge of the radiologic features is necessary to make a specific diagnosis. The findings on radiographs are usually normal. Images from small-bowel follow-through studies show the bowel loops conglomerated in a concertina-like fashion with a serpentine arrangement in a fixed U-shaped configuration. US demonstrates a "cauliflower" appearance of bowel with a narrow base, as well as a "trilaminar" appearance depicted especially with use of high-resolution US probes. CT is the imaging modality of choice and allows identification of the thickened contrast material-enhanced abnormal peritoneal membrane and the encapsulated clumped bowel loops. In addition, CT can potentially help identify the cause of EPS (omental granuloma in tuberculosis), as well as the complications of EPS (bowel obstruction). Conservative medical treatment and surgical therapy early in the course of EPS have been used for management of the condition. The purpose of this article is to review the nomenclature and etiopathogenesis of EPS, describe the multimodality imaging appearances of EPS, including differentiating its features from those of other conditions mimicking EPS, and give an overview of management options. Online DICOM image stacks are available for this article. ^©RSNA, 2018.

Encapsulating peritoneal sclerosis

Encapsulating peritoneal sclerosis (EPS) is a debilitating condition characterized by a fibrocollagenous membrane encasing the small intestine, resulting in recurrent small bowel obstructions. EPS is most commonly associated with long-term peritoneal dialysis, though medications, peritoneal infection, and systemic inflammatory disorders have been implicated. Many cases remain idiopathic. Diagnosis is often delayed given the rarity of the disorder combined with non-specific symptoms and laboratory findings. Although cross-sectional imaging with computed tomography of the abdomen can be suggestive of the disorder, many patients undergo exploratory laparotomy for diagnosis. Mortality approaches 50% one year after diagnosis. Treatment for EPS involves treating the underlying condition or eliminating possible inciting agents (i.e. peritoneal dialysis, medications, infections) and nutritional support, frequently with total parenteral nutrition. EPS-specific treatment depends on the disease stage. In the inflammatory stage, corticosteroids are the treatment of choice, while in the fibrotic stage, tamoxifen may be beneficial. In practice, distinguishing between stages may be difficult and both may be used. Surgical intervention, consisting of peritonectomy and enterolysis, is time-consuming and high-risk and is reserved for situations in which conservative medical therapy fails in institutions with surgical expertise in this area. Herein we review the available literature of the etiology, pathogenesis, diagnosis, and treatment of this rare, but potentially devastating disease.

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.

Abdominal cocoon-A rare cause of intestinal obstruction

INTRODUCTION

Abdominal cocoon syndrome is characterized by small bowel encapsulation by a fibro-collagenous membrane or "cocoon". It is a rare cause of intestinal obstruction.

PRESENTATION OF CASE

A 42-year old man presented with sub-acute intestinal obstruction. Intra-operatively, the entire small bowel was found to be encapsulated in a dense fibrous sac. The peritoneal sac was excised, followed by lysis of the inter-loop adhesions. Postoperative recovery was unremarkable.

DISCUSSION

Most patients with abdominal cocoon syndrome present with features of recurrent acute or chronic small bowel obstruction secondary to kinking and/or compression of the intestines within the constricting cocoon. An abdominal mass may also be present due to an encapsulated cluster of dilated small bowel loops.

CONCLUSION

Abdominal cocoon is a rare condition causing intestinal obstruction and diagnosis requires a high index of suspicion because of the nonspecific clinical picture. CECT of the abdomen is a useful radiological tool to aid in preoperative diagnosis. Peritoneal sac excision and adhesiolysis is the treatment and the outcome is usually satisfactory.

Role of povidone iodine in periapical surgeries: Hemostyptic and anti-inflammatory?

INTRODUCTION

Periapical surgery needs asepsis, a bloodless field for ensuring success of the treatment. Efficacy of Povidone Iodine (PVI) in the elimination of pathogen causing periapical lesions is well established. PVI is also widely used as a disinfectant, sclerosing agent, styptic as well as an anti-odematous agent.

MATERIALS AND METHODS

This prospective pilot study done on 20 males between 20-40 years age group with periapical lesions in single rooted maxillary anterior tooth of 1-2 cm in diameter. The bleeding time, clotting time, bleeding time at the apex, drugs used and visual analogue scale of oedema on postoperative days were obtained. Descriptive statistics, paired t test and independent t-test were used.

RESULTS AND CONCLUSION

Results show a statistically significant reduction in the time required to achieve a bloodless field and a marked decrease in oedema in the first and second postoperative days resulting in lesser consumption of NSAIDs. In conclusion, the effect of PVI in periapical surgery seems to reduce the bleeding time at apex, total dose of NSAIDs used, oedema on first two postoperative days with high statistical significance. Hence the routine use of saline in periapical surgeries may be effectively substituted with PVI. The finding of this pilot study has to be evaluated using wider samples for effective clinical translations.

Are the Mesothelial-to-Mesenchymal Transition, Sclerotic Peritonitis Syndromes, and Encapsulating Peritoneal Sclerosis Part of the Same Process?

Mesothelial-to-mesenchymal transition (MMT) is an autoregulated physiological process of tissue repair that in uncontrolled conditions, such as peritoneal dialysis (PD), can lead to peritoneal fibrosis. The maximum expression of sclerotic peritoneal syndromes (SPS) is the encapsulating peritoneal sclerosis (EPS) for which no specific treatment exists. The SPS includes a wide range of peritoneal fibrosis that appears progressively and is considered as a reversible process, while EPS does not. EPS is a serious complication of PD characterized by a progressive intra-abdominal inflammatory process that results in bridles and severe fibrous tissue formation which cover and constrict the viscera. Recent studies show that transdifferentiated mesothelial cells isolated from the PD effluent correlate very well with the clinical events such as the number of hemoperitoneum and peritonitis, as well as with PD function (lower ultrafiltration and high Cr-MTC). In addition, in peritoneal biopsies from PD patients, the MMT correlates very well with anatomical changes (fibrosis and angiogenesis). However, the pathway to reach EPS from SPS has not been fully and completely established. Herein, we present important evidence pointing to the MMT that is present in the initial peritoneal fibrosis stages and it is perpetual over time, with at least theoretical possibility that MMT initiated the fibrosing process to reach EPS.

In vitro microbiology studies on a new peritoneal dialysis connector

OBJECTIVE

We evaluated the ability of a recently developed peritoneal dialysis (PD) connector to prevent the risk of bacterial transfer to the fluid path after simulated touch and airborne contamination.

METHODS

Staphylococcus epidermidis ATCC1228 and Pseudomonas aeruginosa ATCC27853 strains were used. For touch contamination, 2 μL of a standardized inoculum [1×10(8) colony-forming units (CFU) per milliliter] were deposited on top of the pin closing the fluid path of the patient connector. For airborne contamination, the patient connector was exposed for 15 seconds to a nebulized standardized inoculum. To simulate the patient peritoneum and effluent, the patient connector was pre-attached to a 2-L bag of sterile PD solution. After contamination, the patient connector was attached to the transfer set, the pin was captured, flow control was turned to simulate "patient drain" into the empty bag, and then "patient fill" using the bag pre-attached to the connector. Finally, a new pin was recaptured. The PD solution collected in the bag pre-attached to the connector was run through a 0.20-μm filter for colony counts.

RESULTS

No infected connector transferred bacteria to the fluid path, regardless of the challenge procedure or the strain used.

CONCLUSIONS

Our results show that the new PD connector may fully obviate the risk of bacterial infection, even in the presence of heavy contamination. Further studies are in progress to test our PD connector in a clinical setting.

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.

Influence of antiseptic agents on interleukin-8 release and transmigration of polymorphonuclear neutrophils in a human in vitro model of peritonitis

BACKGROUND

The aim of this study was to evaluate the influence of taurolidine (TAU) and polyhexanid (POLY) on basic inflammatory reactions during peritonitis by using an in vitro model of human peritoneum.

MATERIALS AND METHODS

Human umbilical vein endothelial cells (HUVEC) and human peritoneal mesothelial cells (HPMC; concentration: 2x10(5)/cm2) were brought on a collagen-coated filter insert with 3-microm pore size (HUVEC on the bottom, HPMC on the top), thus resulting in a two-chamber peritoneal model. After 5 days, confluence of the cells was reached, and HPMC were stimulated with 0.5 mL of TNF-alpha (10 microg/mL) for 4 h. Afterwards, 0.5 mL of TAU (1% and 2%) or 0.5 mL of POLY (0.1% and 0.2%) solution were added to the upper (HPMC) compartment. Polymorphonuclear neutrophils (PMN, 10(6)/mL) were placed in the lower compartment 1 h later. After 2 and 6 h, aliquots were taken from the upper compartment and transmigrated PMN were counted. Interleukin-8 (IL-8) concentrations were measured in both compartments by chemiluminescent enzyme immunometric assay. Expression of the adhesion molecules P-selectin and intercellular adhesion molecule-1 (ICAM-1) was assessed by immunohistochemistry. Controls were either TNF-alpha-stimulated HPMC without any antiseptic agents, or stimulated HPMC where TNF-alpha had been substituted by culture medium. Each experiment was performed in triplicate.

RESULTS

Stimulation with TNF-alpha led to a time-dependent increase of IL-8 secretion to the apical compartment resulting in a gradient between both chambers, as well as to a time-dependent increase of PMN transmigration and expression of adhesion molecules. IL-8 gradients and PMN migration were significantly higher as compared to the other groups (p<0.05). After substitution of the stimulus by culture medium, significantly less IL-8 was measured in both compartments. PMN transmigration was almost absent (p<0.05). Addition of POLY and TAU led to comparable low IL-8 gradients with concomitant low PMN transmigration. The initially detected expression of adhesion molecules significantly decreased during the observation time. The IL-8 gradient in all groups correlated significantly with PMN transmigration (r=0.74226; p<0.0001).

CONCLUSION

The diminished IL-8 response together with low PMN transmigration rates after addition of TAU and POLY may reflect either antiinflammatory effects or cellular damage.

[Sclerosing peritonitis]

Sclerosing peritonitis (also described as sclerosing obstructive peritonitis, encapsulating peritonitis, obliterative adhesive peritonitis, abdominal cocoon syndrome) is not well-known by the general surgeon; most reviews of this subject occur in the nephrology literature. Peritoneal dialysis and continuous hyperthermic peritoneal perfusion are the main causes. No controlled study exists to evaluate the optimal therapeutic approach. Pre-operative diagnosis is difficult since the clinical signs and radiologic findings are non-specific. Nevertheless, the diagnosis should be considered when small bowel obstruction with proximal dilatation, ascites, and thickened or calcified peritoneum are seen on imaging. The surgeon should recognize sclerosing peritonitis grossly when it is encountered and adapt his surgical strategy accordingly.

Efeito do uso de povidine-iodine na cicatrização de anastomoses de cólon direito de ratos

RACIONAL: Dados da literatura sugerem que, possivelmente, a lavagem intraluminar de segmentos do tubo digestivo com povidona-iodine antes da execução de uma anastomose poderia favorecer a cicatrização dessas anastomoses e prevenir a formação de aderências perianastomóticas, podendo ser útil se empregada em pacientes submetidos cirurgias do trato digestivo. OBJETIVO: Avaliar a eficácia da lavagem das bordas entéricas com povidona-iodine a 5% sobre a cicatrização do cólon direito de ratos. MATERIAL E MÉTODOS: Estudaram-se 20 ratos Wistar divididos nos seguintes grupos: A (n = 10), limpeza das bordas da ferida colônica com solução salina a 0,9%; B (n = 10), limpeza das bordas da ferida colônica com solução de povidona-iodine a 5%. Os animais foram submetidos a laparotomia, secção de 75% da circunferência do cólon, preservando 25% da borda mesentérica e tratamento das bordas a serem anastomosadas segundo o grupo descrito acima. Após a realização das anastomoses, os animais foram observados durante 7 dias e, no 7º dia pós-operatório, mortos. Foram coletadas amostras de sangue para dosagem da albumina sérica e feita análise macroscópica das anastomoses, observando-se presença de fístula, aderências e dilatação acima da anastomose. O segmento contendo a anastomose colônica foi retirado com 3 cm de cólon intacto em torno da anastomose e feita medida da pressão de ruptura. RESULTADOS: Não se observou presença de fístula em nenhum animal dos grupos estudados. Não houve diferença significativa em relação à presença de estenose da anastomose, aderências ou no valor da pressão de ruptura quando comparados os dois grupos. CONCLUSÃO: O emprego da povidona-iodine não resultou em aumento da resistência tênsil das anastomoses do cólon direito de ratos.

[Evaluation of povidone abdominal washing for prevention of peritoneal cancer cell seeding: experimental study in the rat]

GOAL

The aim of the study was to evaluate the in vitro cytototoxicity of diluted povidone iodine on colon cancer cells and its in vivo antitumoral effect in a model of peritoneal carcinomatosis in the rat.

METHODS

Cell cytotoxicity of a povidone iodine diluted solution was assessed, in vitro, on rat colon cancer cells (DHD/K12/PROb) and human colon cancer cells (HT29). The antitumoral effect of diluted povidone iodine washing was measured in BDIX rats after the intraperitoneal inoculation of 10(6) DHD/K12/PROb cells. Results were compared to an abdominal washing within a 9 g/l salinel solution. In one experiment, peritoneal scars and a colocolic anastomosis were performed after the injection of cancer cells.

RESULTS

A short 10 min incubation of human and rat colon cancer cells with diluted povidone iodine resulted in a complete cell killing. In animals, a peritoneal washing with 1% diluted povidone iodine completely inhibited the tumor growth in parietal peritoneum. However, development of peritoneal tumor nodules was not inhibited in the omentum, in scarified peritoneum or in intestinal anastomosis.

CONCLUSIONS

Despite its high in vitro efficacy, diluted povidone iodine has an incomplete effect in the prevention of peritoneal carcinomatosis, with only a partial inhibition in scarred peritoneum epiploïc area and intestinal anastomosis. In contrary, it procures a complete inhibition of tumor growth in normal peritoneum.

Limitations of peritoneal lavage with antiseptics in prevention of recurrent colorectal cancer caused by tumor-cell seeding: experimental study in rats

PURPOSE

Exfoliated or soiled free malignant cells have serious consequences in patients undergoing gastrointestinal cancer surgery. The present study evaluates the toxicity and efficacy of cytotoxic agents in the prevention of cell seeding and tumor growth in the peritoneal cavity in an experimental model.

METHODS

Mtln3 adenocarcinoma cell viability was tested in vitro using the trypan blue exclusion test after incubation with povidone-iodine or chlorhexidine. In vivo, Fischer rats were inoculated with 10(5) or 10(6) cells followed by peritoneal lavage with physiological saline, chlorhexidine 0.02 percent, povidone-iodine low molecular weight 1 percent or povidone-iodine high molecular weight 1 and 2 percent in different quantities and incubation times.

RESULTS

Chlorhexidine 0.02 percent and povidone-iodine low molecular weight 1 percent or high molecular weight 2 percent, killed over 98 percent of 10(5) or 10(6) tumor cells in vitro. Povidone-iodine low molecular weight 1 percent and high molecular weight 2 percent were toxic and lethal when 5 ml were applied in the peritoneal cavity three times for five minutes. Chlorhexidine 0.02 percent applied after inoculation of 10(5) or 10(6) cells, reduced the tumor development only to 70 and 80 percent. Application of 5 ml povidone-iodine 1 percent low molecular weight or high molecular weight, three times for one and five minutes, after inoculation of 10(6) cells did not change the tumor take. However, inhibition of Mtln3 cells to form metastases was observed. When povidone-iodine low molecular weight 1 percent was used three times for one minute after 10(5) tumor cells were "soiled", no toxicity was observed and the tumor take was reduced to 30 percent (P < 0.05).

CONCLUSIONS

Povidone-iodine toxicity proved to be a major issue in vivo. However, povidone-iodine low molecular weight 1 percent was safe when used for short periods and very effective when a limited number of tumor cells was inoculated. The use of cytotoxic agents to prevent recurrent disease caused by tumor cell seeding in patients seems to make sense only when the "inoculum size" of exfoliated or soiled cancer cells is limited.

Peritoneal sclerosis: one or two nosological entities?

The frequency, pathology, animal models, pathogenesis, clinical manifestations, diagnostic criteria, therapy and prevention of peritoneal sclerosis are reviewed. Many of these aspects have a bimodal configuration which suggests that peritoneal sclerosis, usually considered a single pathology in peritoneal dialysis, is actually two distinct nosological entities: simple sclerosis and sclerosing peritonitis. The former is very frequent, with minor anatomical alterations and low clinical impact; it is reproducible in animals by means of peritoneal dialysis, and is clearly due to the poor biocompatibility of peritoneal dialysis solutions. The latter is rare, with radical anatomical alterations and high mortality requiring valid methods of diagnosis, therapy and prevention; it can only be reproduced in animal models by means other than peritoneal dialysis and seems to be due to factors both related and unrelated to peritoneal dialysis.

Peritoneal irrigation with povidone-iodine solution after laparoscopic-assisted splenectomy significantly decreases port-tumor recurrence in a murine model

PURPOSE

The development of port-wound tumor recurrences has raised questions regarding the safety of laparoscopic methods for the resection of malignancies. The cause and the incidence of abdominal-wall tumor recurrences remain unknown. It is also not clear how to avoid or lower the incidence of port-tumor recurrences. The purpose of the current study was to determine the impact of abdominal irrigation with povidone-iodine on the port-wound tumor incidence in a murine model.

METHODS

A splenic tumor model was used for this study. To establish splenic tumors, female BALB/c mice (N = 48) were given subcapsular splenic injections of a 0.1 ml suspension containing 10(5) C-26 colon adenocarcinoma cells via a left-flank incision at the initial procedure. Seven days later, the animals with isolated splenic tumors (100 percent) were randomly assigned to one of three groups: 1) control, 2) saline irrigation (saline), or 3) povidone-iodine irrigation. All animals underwent laparoscopic mobilization of the spleen using a three-port technique, intra-abdominal crushing of the tumor, followed by an extracorporeal splenectomy via a subcostal incision. No irrigation was performed for control group animals. In the saline irrigation group, the subcostal incision was closed and pneumoperitoneum was re-established. The abdominal cavity was irrigated with 5 ml of normal saline for 60 seconds before instrument removal. In the povidone-iodine irrigation group, similar abdominal irrigation was performed, using 0.25 percent povidone-iodine. Attempts were made to recover completely the irrigation for both irrigation groups. Seven days after the splenectomy, animals were killed and inspected for abdominal-wall tumor implants.

RESULTS

There were significantly more animals with at least one port-tumor recurrence in the control group than in the povidone-iodine group (P = 0.007). Although not statistically significant, the number of animals with port-wound tumors was higher in the saline group than in the povidone-iodine group (P < 0.08). There was no significant difference between the saline group and the control group. When each port site was considered independently, the incidence of port-wound tumors (number of ports with tumors per total number of ports) was significantly lower in the povidone-iodine group than in both the control (P = 0.00001) and saline groups (P = 0.03). The incidence of port-wound tumors was also significantly lower in the saline group compared with the control group incidence (P = 0.03).

CONCLUSIONS

Abdominal irrigation with dilute povidone-iodine solution significantly reduced the number of animals with port-tumor recurrences. Abdominal irrigation with saline was also effective in reducing the incidence of port-wound tumor formation when each port was considered separately. However, povidone-iodine irrigation was much more effective than saline irrigation in preventing port-wound tumor formation.