A comparison of ultrasound guided bilateral single injection shot Erector Spinae Plane blocks versus wound infiltration for post-operative analgesia in laparoscopic assisted colonic surgery- a prospective randomised study.

BACKGROUND: Both wound infiltration (WI) with local anaesthetic and Erector Spinae Plane block (ESPB) have been described for post-operative analgesia after abdominal surgery. This study compared the efficacy of WI versus ESPB for post-operative analgesia after laparoscopic assisted colonic surgery. METHODS: Seventy-two patients between 18 and 85 years of age undergoing elective surgery were randomised to receive either WI or ESPB. In the WI group a 40 ml bolus of 0.5% Ropivacaine, infiltrated at the ports and minimally invasive wound at subcutaneous and fascia layers. In the ESPB group at T8 level, under ultrasound guidance, a 22-gauge nerve block needle was passed through the Erector Spinae muscle to reach its fascia. A dose up to 40 ml of 0.5% Ropivacaine, divided into two equal volumes, was injected at each side. Both groups had a multimodal analgesic regime, including regular Paracetamol, dexamethasone and patient-controlled analgesia (PCA) with Fentanyl. The primary end point was a post-operative pain score utilising a verbal Numerical Rating Score (NRS, 0-10) on rest and coughing in the post anaesthetic care unit (PACU) and in the first 24 h. Secondary outcomes measured were: opioid usage, length of stay and any clinical adverse events. RESULTS: There was no significant treatment difference in PACU NRS at rest and coughing (p-values 0. 382 and 0.595respectively). Similarly, there were no significant differences in first 24 h NRS at rest and coughing (p-values 0.285 and 0.431 respectively). There was no significant difference in Fentanyl use in PACU or in the first 24 h (p- values 0.900 and 0.783 respectively). Neither was there a significant difference found in mean total Fentanyl use between ESPB and WI groups (p-value 0.787). CONCLUSION: Our observations found both interventions had an overall similar efficacy. TRIAL REGISTRATION: The study was registered with the Australian New Zealand Clinical Trial Registry (ACTRN: 12619000113156 ).

Pravastatin for early-onset pre-eclampsia: a randomised, blinded, placebo-controlled trial.

OBJECTIVE: Women with pre-eclampsia have elevated circulating levels of soluble fms-like tyrosine kinase-1 (sFlt-1). Statins can reduce sFlt-1 from cultured cells and improve pregnancy outcome in animals with a pre-eclampsia-like syndrome. We investigated the effect of pravastatin on plasma sFlt-1 levels during pre-eclampsia. DESIGN: Blinded (clinician and participant), proof of principle, placebo-controlled trial. SETTING: Fifteen UK maternity units. POPULATION: We used a minimisation algorithm to assign 62 women with early-onset pre-eclampsia (24+0 -31+6  weeks of gestation) to receive pravastatin 40 mg daily (n = 30) or matched placebo (n = 32), from randomisation to childbirth. PRIMARY OUTCOME: Difference in mean plasma sFlt-1 levels over the first 3 days following randomisation. RESULTS: The difference in the mean maternal plasma sFlt-1 levels over the first 3 days after randomisation between the pravastatin (n = 27) and placebo (n = 29) groups was 292 pg/ml (95% CI -1175 to 592; P = 0.5), and over days 1-14 was 48 pg/ml (95% CI -1009 to 913; P = 0.9). Women who received pravastatin had a similar length of pregnancy following randomisation compared with those who received placebo (hazard ratio 0.84; 95% CI 0.50-1.40; P = 0.6). The median time from randomisation to childbirth was 9 days (interquartile range [IQR] 5-14 days) for the pravastatin group and 7 days (IQR 4-11 days) for the placebo group. There were three perinatal deaths in the placebo-treated group and no deaths or serious adverse events attributable to pravastatin. CONCLUSIONS: We found no evidence that pravastatin lowered maternal plasma sFlt-1 levels once early-onset pre-eclampsia had developed. Pravastatin appears to have no adverse perinatal effects. TWEETABLE ABSTRACT: Pravastatin does not improve maternal plasma sFlt-1 or placental growth factor levels following a diagnosis of early preterm pre-eclampsia #clinicaltrial finds.

Comparison of ultrasound-guided transmuscular quadratus lumborum block catheter technique with surgical pre-peritoneal catheter for postoperative analgesia in abdominal surgery: a randomised controlled trial.

Following abdominal surgery, the provision of postoperative analgesia with local anaesthetic infusion through both transmuscular quadratus lumborum block and pre-peritoneal catheter have been described. This study compared these two methods of postoperative analgesia following laparotomy. Eighty-two patients 18-85 years of age scheduled to undergo elective surgery were randomly allocated to receive either transmuscular quadratus lumborum block or pre-peritoneal catheter block. In the transmuscular quadratus lumborum group, an 18-gauge Tuohy needle was passed through the quadratus lumborum muscle under ultrasound guidance to reach its anterior aspect. A 20-ml bolus of ropivacaine 0.375% was administered and catheters placed bilaterally. In the pre-peritoneal catheter group, 20 ml of ropivacaine 0.375% was infiltrated at each of three subcutaneous sub-fascial levels, and pre-peritoneal plane catheters were placed bilaterally. Both groups received an infusion of ropivacaine 0.2% at 5 ml.h-1 , continued up to 48 h along with a multimodal analgesic regime that included regular paracetamol and patient-controlled analgesia with fentanyl. The primary end-point was postoperative pain score on coughing, assessed using a numerical rating score (0-10). Secondary outcomes were pain score at rest, fentanyl usage until 48 h post-operation, satisfaction scores and costs. There was no treatment difference between the two groups for pain score on coughing (p = 0.24). In the transmuscular quadratus lumborum group, there was a reduction in numerical rating score at rest (p = 0.036) and satisfaction scores on days 1 and 30 (p = 0.004, p = 0.006, respectively), but fentanyl usage was similar. In the transmuscular quadratus lumborum group, the highest and lowest blocks observed in the recovery area were T4 and L1, respectively. The transmuscular quadratus lumborum technique cost 574.64 Australian dollars more per patient than the pre-peritoneal catheter technique.

Non-technical skills of surgical trainees and experienced surgeons.

BACKGROUND: In addition to technical expertise, surgical competence requires effective non-technical skills to ensure patient safety and maintenance of standards. Recently the Royal Australasian College of Surgeons implemented a new Surgical Education and Training (SET) curriculum that incorporated non-technical skills considered essential for a competent surgeon. This study sought to compare the non-technical skills of experienced surgeons who completed their training before the introduction of SET with the non-technical skills of more recent trainees. METHODS: Surgical trainees and experienced surgeons undertook a simulated scenario designed to challenge their non-technical skills. Scenarios were video recorded and participants were assessed using the Non-Technical Skills for Surgeons (NOTSS) scoring system. Participants were divided into subgroups according to years of experience and their NOTSS scores were compared. RESULTS: For most NOTSS elements, mean scores increased initially, peaking around the time of Fellowship, before decreasing roughly linearly over time. There was a significant downward trend in score with increasing years since being awarded Fellowship for six of the 12 NOTSS elements: considering options (score -0·015 units per year), implementing and reviewing decisions (-0·020 per year), establishing a shared understanding (-0·014 per year), setting and maintaining standards (-0·024 per year), supporting others (-0·031 per year) and coping with pressure (-0·015 per year). CONCLUSION: The drop in NOTSS score was unexpected and highlights that even experienced surgeons are not immune to deficiencies in non-technical skills. Consideration should be given to continuing professional development programmes focusing on non-technical skills, regardless of the level of professional experience.

Prospective randomized trial of neoadjuvant chemotherapy during the 'wait period' following preoperative chemoradiotherapy for rectal cancer: results of the WAIT trial.

AIM: The aim was to determine whether the addition of additional cycles of chemotherapy during the 'wait period' following neoadjuvant chemoradiotherapy for rectal cancer improves the pathological complete response (pCR) rate. METHOD: Rectal cancer patients were randomly allocated either to a standard 10 week wait period before surgery (standard chemoradiotherapy, SCRT) or to receive three cycles of fluorouracil based chemotherapy following chemoradiotherapy during a similar 10 week wait (extended chemoradiotherapy, XCRT). The primary end-point was pCR as determined by blinded pathological assessment. RESULTS: Forty-nine patients were randomized (SCRTn = 24, XCRTn = 25). pCR occurred in 10 patients overall but there was no significant difference in pCR between the groups (SCRTn = 6, XCRTn = 4, P = 0.49). CONCLUSION: The addition of three cycles of 5-fluorouracil/leucovorin in a 10 week wait period after conventional chemoradiotherapy seems to result in similar pCR rates in patients with locally advanced rectal cancer based on this small randomized trial.

Surgeons' and trainees' perceived self-efficacy in operating theatre non-technical skills.

BACKGROUND: An important factor that may influence an individual's performance is self-efficacy, a personal judgement of capability to perform a particular task successfully. This prospective study explored newly qualified surgeons' and surgical trainees' self-efficacy in non-technical skills compared with their non-technical skills performance in simulated scenarios. METHODS: Participants undertook surgical scenarios challenging non-technical skills in two simulation sessions 6 weeks apart. Some participants attended a non-technical skills workshop between sessions. Participants completed pretraining and post-training surveys about their perceived self-efficacy in non-technical skills, which were analysed and compared with their performance in surgical scenarios in two simulation sessions. Change in performance between sessions was compared with any change in participants' perceived self-efficacy. RESULTS: There were 40 participants in all, 17 of whom attended the non-technical skills workshop. There was no significant difference in participants' self-efficacy regarding non-technical skills from the pretraining to the post-training survey. However, there was a tendency for participants with the highest reported self-efficacy to adjust their score downwards after training and for participants with the lowest self-efficacy to adjust their score upwards. Although there was significant improvement in non-technical skills performance from the first to second simulation sessions, a correlation between participants' self-efficacy and performance in scenarios in any of the comparisons was not found. CONCLUSION: The results suggest that new surgeons and surgical trainees have poor insight into their non-technical skills. Although it was not possible to correlate participants' self-belief in their abilities directly with their performance in a simulation, in general they became more critical in appraisal of their abilities as a result of the intervention.

Systematic review of skills transfer after surgical simulation-based training.

BACKGROUND: Simulation-based training assumes that skills are directly transferable to the patient-based setting, but few studies have correlated simulated performance with surgical performance. METHODS: A systematic search strategy was undertaken to find studies published since the last systematic review, published in 2007. Inclusion of articles was determined using a predetermined protocol, independent assessment by two reviewers and a final consensus decision. Studies that reported on the use of surgical simulation-based training and assessed the transferability of the acquired skills to a patient-based setting were included. RESULTS: Twenty-seven randomized clinical trials and seven non-randomized comparative studies were included. Fourteen studies investigated laparoscopic procedures, 13 endoscopic procedures and seven other procedures. These studies provided strong evidence that participants who reached proficiency in simulation-based training performed better in the patient-based setting than their counterparts who did not have simulation-based training. Simulation-based training was equally as effective as patient-based training for colonoscopy, laparoscopic camera navigation and endoscopic sinus surgery in the patient-based setting. CONCLUSION: These studies strengthen the evidence that simulation-based training, as part of a structured programme and incorporating predetermined proficiency levels, results in skills transfer to the operative setting.

Effect of preoperative two-dimensional animation information on perioperative anxiety and knowledge retention in patients undergoing bowel surgery: a randomized pilot study.

AIM: The use of multimedia information provided preoperatively can potentially reduce anxiety in patients and improve the hospital experience. However, the use of two-dimensional (2D) animation (cartoon) to provide information to patients undergoing colorectal surgery has not been investigated. This study investigated the effect of preoperative 2D information on anxiety and knowledge retention in patients undergoing bowel surgery. METHOD: Patients were randomized to one of two groups; the video group watched a 13-min cartoon animation whereas the nonvideo group did not. Anxiety levels were measured at the preadmission clinic, postvideo, on the day of admission for surgery, within 24-h after surgery and before discharge using the Spielberger state-trait anxiety inventory and visual analogue scale. Both groups completed a knowledge retention questionnaire and the video group completed a feedback questionnaire about the animation. RESULTS: Thirty-one patients (16 video, 15 nonvideo) participated in the study. There was no significant difference in baseline anxiety score between two groups. An immediate reduction (P = 0.03) in anxiety score was observed in the video group after watching the video compared with baseline. There was a significant reduction in anxiety score in the video group at discharge compared with the nonvideo group (P = 0.03). There was no significant difference in knowledge retention between two groups. Eighty-eight per cent of patients who watched the video found it beneficial. CONCLUSION: 2D animation is an effective medium for delivering information to patients undergoing bowel surgery and can potentially reduce anxiety related to surgery and improve the hospital experience.

The nursing and financial implications of laparoscopic colorectal surgery: data from a randomized controlled trial.

AIM: The issue of cost effectiveness of laparoscopic surgery remains uncertain and its impact on the ward nursing staff is unaddressed. This study investigated these issues using patients from a single centre admitted to a randomized controlled trial. METHOD: All patients recruited into the Australasian Laparoscopic Colon Cancer Study (ALCCaS) from The Queen Elizabeth Hospital between January 1999 and March 2005 were included in this study. Data relating to hospital cost were collated from the Hospital Patient Costing System. Nursing interventions were calculated in minutes per patient, using the excelcare Software database. RESULTS: Data from 97 patients were analysed (laparoscopy, 53; open surgery, 44). The median number of hours of nursing input per patient was 80 (27.5-907) h in the open surgery group and 58.5 (15-684.5) h in the laparoscopy group. This difference was further increased after exclusion of patients converted from laparoscopy to open surgery. The median total cost of the procedure was AUS $9698/£ 5631 (AUS $3862-90,397) in the open surgery group and AUS $10,951/£ 6219 (AUS$2337-66,237) in the laparoscopy group. CONCLUSION: These data suggest that laparoscopic colorectal surgery is equivalent in price to open surgery and there may be added benefits in reduced nursing intensity.

Australasian Laparoscopic Colon Cancer Study shows that elderly patients may benefit from lower postoperative complication rates following laparoscopic versus open resection.

BACKGROUND: A retrospective analysis of age-related postoperative morbidity in the Australia and New Zealand prospective randomized controlled trial comparing laparoscopic and open resection for right- and left-sided colonic cancer is presented. METHODS: A total of 592 eligible patients were entered and studied from 1998 to 2005. RESULTS: Data from 294 patients who underwent laparoscopic and 298 who had open colonic resection were analysed; 266 patients were aged less than 70 years and 326 were 70 years or older (mean(s.d.) 70.3(11.0) years). Forty-three laparoscopic operations (14.6 per cent) were converted to an open procedure. Fewer complications were reported for intention-to-treat laparoscopic resections compared with open procedures (P = 0.002), owing primarily to a lower rate in patients aged 70 years or more (P = 0.002). Fewer patients in the laparoscopic group experienced any complication (P = 0.035), especially patients aged 70 years or above (P = 0.019). CONCLUSION: Treatment choices for colonic cancer depend principally upon disease-free survival; however, patients aged 70 years or over should have rigorous preoperative investigation to avoid conversion and should be considered for laparoscopic colonic resection. REGISTRATION NUMBER: NCT00202111 (http://www.clinicaltrials.gov).

Laparoscopically assisted colectomy: a study of risk factors and predictors of open conversion.

BACKGROUND: Conversion to an open procedure during laparoscopically assisted colorectal resection may be necessary because of technical, patient, or pathologic factors. Recent literature has indicated that converted patients may have poorer outcomes than those undergoing open or completed laparoscopically assisted procedure. This study aimed to audit the authors' experience with laparoscopically assisted colectomy and to assess the clinical outcomes of patients undergoing conversion. METHODS: All laparoscopic right hemicolectomies or anterior resections performed at seven South Australian hospitals from 1997 to 2006 were reviewed. Data pertaining to patient sex, age, American Society of Anesthesiology (ASA) score, pathology, operative outcomes including operating time, conversion, reason for conversion, length of hospital stay, and intra- and postoperative complications were analyzed. RESULTS: Laparoscopic anterior resection had a higher rate of open conversion than laparoscopic right hemicolectomy (18.7% vs 10.4%; p = 0.028). In the right hemicolectomy group, none of the investigated risk factors for conversion were statistically significant, and the morbidity rates for the two groups were similar. The median hospital stay was significantly longer in the anterior resection group (p < 0.001), and the wound morbidity rate was higher in the converted group (12.8% vs 3.0%; p = 0.022). Age older than 75 years and a high ASA status were independent risk factors for conversion in anterior resection. CONCLUSIONS: Conversion of laparoscopic anterior resection to open procedure is associated with higher wound morbidity and a longer hospital stay. The authors recommend that surgeons carefully consider the selection of patients 75 years of age or older and high ASA status for laparoscopic anterior resection.

Management and survival trends in advanced colorectal cancer.

AIMS: Significant improvements in the outcome for patients with advanced colorectal cancer (CRC) have been achieved. The median survival for advanced CRC reported in clinical trials now approaches 2 years, but there is often a question as to whether this partly represents patient selection. We aimed to explore whether the availability of new chemotherapy drugs (irinotecan and oxaliplatin) and surgical advances have affected survival in a normal clinical setting. MATERIALS AND METHODS: A review of the Queen Elizabeth and Lyell McEwin health service prospective CRC database from 1992 to 2004 was carried out to assess outcome differences between two time cohorts (1 January 1992-31 December 1997 and 1 January 1998-31 December 2004). RESULTS: For all patients (n = 744) overall survival was seen to improve over time and is maintained out to 5 years. There have been a number of trends over time (1992-1997 vs 1998-2004) that have probably contributed to this gain; increased overall chemotherapy use (33% vs 43%); use of combination chemotherapy (i.e. oxaliplatin and irinotecan regimens); increased hepatic resection rates (1.9% vs 10.8%) and increased clinical trial uptake (0.6% vs 14.5%). CONCLUSION: This current analysis confirms an improvement in survival over time for advanced CRC and this is seen in unselected patients including those over 70 years of age.

Identification of tumour-induced changes in endothelial cell surface protein expression: an in vitro model.

The selective destruction of the supporting vasculature of tumours has been proposed as a means of therapy. Fundamental to this approach is the identification of suitable targets on tumour-endothelium. To detect proteins that may be up-regulated on the luminal (apical) surface of tumour-associated endothelium confluent endothelial cells were examined following incubation with tumour cell conditioned medium (TCM) from, or co-culture with, a range of breast carcinoma and small cell lung carcinoma (SCLC) cell lines. Exposed endothelial membrane proteins were labelled with sulpho-NHS-biotin and detected by enhanced chemiluminescence following two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and western blotting. TCM induced varying levels of proliferative activity in endothelial cells; generally breast TCM contained greater mitogenic activity than SCLC TCM. Exposure of human breast and lung microvascular, and umbilical vein endothelial cells to soluble tumour cell factors from several breast cancer and SCLC cells lines produced similar changes in luminal protein profiles: Breast cancer cells and in particular the MDA-MB-231 cell line induced the most pronounced changes. The expression of six proteins was altered consistently on endothelial cells stimulated with soluble tumour cell factors. However, similar changes were observed following incubation with ECGS suggesting that they were related to endothelial cell proliferation per se. As these proteins were altered in breast and lung microvascular, and umbilical vein endothelial cells stimulated by a variety of breast cancer and SCLC cell lines they support the potentially broad applicability of anti-vascular approaches targeted at the endothelium.

Selective expression of erg isoforms in human endothelial cells.

Erg and Fli-1 are closely related members of the ets family of transcription factors. There are at least five human Erg isoforms (Erg-1, Erg-2, Erg-3/p55(Erg), p49(Erg) and p38(Erg)) produced through differential mRNA splicing and alternative use of translational start codons. However, relatively little is known about the expression or function of these isoforms in vitro or their distribution in vivo. We used RT-PCR to screen a panel of primary and established human cell lines for erg and fli-1 consensus sequences. Whilst fli-1 was expressed in several human cell types, erg was detected mainly in endothelial cells. To identify which erg isoforms are expressed in endothelial cells we used RT-PCR, Northern blotting and 5'-RACE. Erg-3/p55(Erg) and p38(Erg)/p38(Erg)-like transcripts were detected in both microvascular and large vessel endothelial cells affinity-purified from different vascular beds. Moreover, these erg isoforms were present in both freshly isolated, and confluent endothelial cells following several passages in culture, indicating that endothelial erg expression in vitro may be broadly representative of that in vivo. The selective expression of the Erg-3/p55(Erg) and p38(Erg)/p38(Erg)-like isoforms in endothelial cells indicates their involvement in the regulation of endothelial-restricted genes.

Receptor protein tyrosine kinase EphB4 is up-regulated in colon cancer.

BACKGROUND: We have used commercially available cDNA arrays to identify EphB4 as a gene that is up-regulated in colon cancer tissue when compared with matched normal tissue from the same patient. RESULTS: Quantitative RT-PCR analysis of the expression of the EphB4 gene has shown that its expression is increased in 82% of tumour samples when compared with the matched normal tissue from the same patient. Using immunohistochemistry and Western analysis techniques with an EphB4-specific antibody, we also show that this receptor is expressed in the epithelial cells of the tumour tissue and either not at all, or in only low levels, in the normal tissue. CONCLUSION: The results presented here supports the emerging idea that Eph receptors play a role in tumour formation and suggests that further elucidation of this signalling pathway may identify useful targets for cancer treatment therapies.

Dipeptidase 1: a candidate tumor-specific molecular marker in colorectal carcinoma.

The aim of this study was to identify tumor-specific markers for the detection of rare disseminated colorectal tumor cells in peripheral venous blood and in intra-peritoneal saline lavage samples collected before and after resection of colorectal tumors. Using cDNA micro-array screening, we found dipeptidase 1 (DPEP1) to be highly expressed in colon tumors compared to matched normal mucosa. Relative reverse transcriptase (RT)-PCR showed that DPEP1 was over-expressed by >/=2 fold in colon tumor compared to normal colonic mucosal tissue in 56/68 (82%) patients. Using immunobead RT-PCR, a technique that first enriches for epithelial cells, we found DPEP1 positive cells in intra-peritoneal lavage and venous blood samples from 15/38 (39%) colorectal cancer cases. This is the first report of DPEP1 as a marker for disseminated colon tumor cells.

The activity of caspase-3-like proteases is elevated during the development of colorectal carcinoma.

Activated caspase-3-like proteases promote apoptotic cell death by cleaving cellular substrates. Caspase-3-like activity was measured in colonic carcinomas and in matched normal colonic mucosa from 31 patients and was significantly elevated in 25/ 31 colonic carcinomas and adenomas when compared to normal mucosa (P < 0.0001). Caspase-3-like activity was much higher in normal mucosa and tumours of female subjects than of males (P < 0.0001). No correlation was obtained between caspase-3-like activity and location of the tumour, tumour grade, stage, or patient age. The marked increase in caspase-3-like activity in colorectal carcinomas may reflect an increase in the proportion of cells undergoing spontaneous apoptosis.

An unusual case of port site seeding.

We present an unusual case of a port site tumor from a colonic adenocarcinoma following laparoscopic cholecystectomy. A 66-year-old woman with a previous renal transplant underwent elective laparoscopic cholecystectomy for symptomatic cholelithiasis. Three months later, she re-presented with pain localized to the right lateral port wound. Subsequent investigation revealed an adenocarcinoma in the ascending colon with no evidence of local spread or liver metastases. The patient was enrolled in the ALCCAS trial (an Australasian multicenter prospective randomized clinical study comparing laparoscopic and conventional open surgical treatments of colon cancer in adults) and randomized to the laparoscopic arm. At laparoscopy, nodules of tumor were located at the sites of the previous right flank and umbilical trocar sites. The procedure was converted to an open hemicolectomy with excision of port sites. To our knowledge, only one other case of a colon carcinoma metastasizing to a port site following laparoscopic cholecystectomy has been reported. This case illustrates a number of points: (a) This was an advanced tumor at the time of diagnosis and was undoubtedly present at laparoscopic cholecystectomy. (b) This tumor was not manipulated at the time of laparoscopic cholecystectomy. (c) The patient was immunosuppressed at the time of laparoscopic cholecytstectomy. (d) The patient developed clinical recurrence in her laparotomy wound within 3 months of her open procedure. This case supports current arguments that the etiology of port site metastases is likely to be mulifactorial.

The effect of lavage on intraabdominal cell burden.

BACKGROUND: Abdominal lavage is a common surgical practice, but few studies have been conducted to assess its efficacy at removing cells from the abdominal cavity, particularly during laparoscopic surgery. METHODS: After three 12-mm trocars were inserted into six female 30-kg pigs at the umbilicus left and right iliac fossae, the abdomen was insufflated with carbon dioxide. The pelvis of each pigs was injected with 6 million radiolabeled LIM 1215 cells. Then the abdominal cavity was irrigated with either 500 ml 0.9% saline, 500 ml 10% betadine solution, or 1 L 0.9% saline. A maximum of 5 L of solution was used for each animal. The lavage fluid was suctioned into separate containers after each aliquot, and each container was measured for radioactivity. RESULTS: Significantly greater numbers of cells were removed by lavage by the first to third lavage cycle; however, after four lavage cycles, relatively few cells were removed by each further cycle. No difference was observed between 500-ml and 1-L aliquots. Additionally, the mechanical efficacy of 0.9% saline and 10% betadine solution appeared similar. CONCLUSION: These findings suggest that optimal lavage consists of four irrigation/suction cycles utilizing 500-ml aliquots.