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Biomedical subjects

Guy J Maddern

Publications and source records attributed to Guy J Maddern.

At least 19 recordsLinked to original sources
PubMed2006

Radiofrequency ablation of liver tumors: a systematic review.

OBJECTIVES: To systematically review radiofrequency ablation (RFA) for treating liver tumors. DATA SOURCES: Databases were searched in July 2003. STUDY SELECTION: Studies comparing RFA with other therapies for hepatocellular carcinoma (HCC) and colorectal liver metastases (CLM) plus selected case series for CLM. DATA EXTRACTION: One researcher used standardized data extraction tables developed before the study, and these were checked by a second researcher. DATA SYNTHESIS: For HCC, 13 comparative studies were included, 4 of which were randomized, controlled trials. For CLM, 13 studies were included, 2 of which were nonrandomized comparative studies and 11 that were case series. There did not seem to be any distinct differences in the complication rates between RFA and any of the other procedures for treatment of HCC. The local recurrence rate at 2 years showed a statistically significant benefit for RFA over percutaneous ethanol injection for treatment of HCC (6% vs 26%, 1 randomized, controlled trial). Local recurrence was reported to be more common after RFA than after laser-induced thermotherapy, and a higher recurrence rate and a shorter time to recurrence were associated with RFA compared with surgical resection (1 nonrandomized study each). For CLM, the postoperative complication rate ranged from 0% to 33% (3 case series). Survival after diagnosis was shorter in the CLM group treated with RFA than in the surgical resection group (1 nonrandomized study). The CLM local recurrence rate after RFA ranged from 4% to 55% (6 case series). CONCLUSIONS: Radiofrequency ablation may be more effective than other treatments in terms of less recurrence of HCC and may be as safe, although the evidence is scant. There was not enough evidence to determine the safety or efficacy of RFA for treatment of CLM.

Carcinoma, Hepatocellular↗
PubMed2006

Evaluating new surgical techniques in Australia: the Australian Safety and Efficacy Register of New Interventional Procedures-Surgical experience.

The Australian Safety and Efficacy Register of New Interventiona lProcedures-Surgical (ASERNIP-S) exists primarily to assess new surgical technologies and techniques. It originally conducted systematic literature reviews, but now uses accelerated reviews, horizon scanning for emerging procedures, research and clinical audits,preparation of patient information, assistance with guideline development,and the production of research protocols of new surgical techniques. Future international cooperation and networking among health technology assessment groups will avoid duplication of effort and maximize outputs. Experience has shown that when surgeons lead in assessing new and emerging surgical techniques and technologies, the benefits of an evidence-based approach are realized, and the surgical community accepts the complementary role of evidence-based medicine in the provision of high-quality patient care.

Australia↗
PubMed2006

Surgical simulation: a systematic review.

OBJECTIVE: To evaluate the effectiveness of surgical simulation compared with other methods of surgical training. SUMMARY BACKGROUND DATA: Surgical simulation (with or without computers) is attractive because it avoids the use of patients for skills practice and provides relevant technical training for trainees before they operate on humans. METHODS: Studies were identified through searches of MEDLINE, EMBASE, the Cochrane Library, and other databases until April 2005. Included studies must have been randomized controlled trials (RCTs) assessing any training technique using at least some elements of surgical simulation, which reported measures of surgical task performance. RESULTS: Thirty RCTs with 760 participants were able to be included, although the quality of the RCTs was often poor. Computer simulation generally showed better results than no training at all (and than physical trainer/model training in one RCT), but was not convincingly superior to standard training (such as surgical drills) or video simulation (particularly when assessed by operative performance). Video simulation did not show consistently better results than groups with no training at all, and there were not enough data to determine if video simulation was better than standard training or the use of models. Model simulation may have been better than standard training, and cadaver training may have been better than model training. CONCLUSIONS: While there may be compelling reasons to reduce reliance on patients, cadavers, and animals for surgical training, none of the methods of simulated training has yet been shown to be better than other forms of surgical training.

Computer Simulation↗
PubMed2006

Relaxation of the criteria for day surgery laparoscopic cholecystectomy.

BACKGROUND: For day case laparoscopic cholecystectomy programmes, studies suggest that overnight admission may be predicted by the following factors: gall bladder wall thickness, patient age over 55 years and previous sphincterotomy. This study investigated the effect of relaxing selection for a day surgery laparoscopic cholecystectomy programme, by removing these factors from the exclusion criteria. METHODS: Between September 2002 and April 2003, patients for elective laparoscopic cholecystectomy were considered for day surgery subject to standard criteria. For the initial part of the programme, patients were additionally excluded according to the risk factors mentioned above. RESULTS: Thirty-three patients underwent intended day case procedures. The first 16 were selected according to the more rigorous criteria. The latter 17 were significantly older, with a significantly higher incidence of gall bladder wall thickening. There were seven admissions, three in the former part of the study and four in the latter. CONCLUSION: The exclusion criteria described are not necessary for a good same-day discharge rate.

Adult↗
PubMed2006

Hepatectomy for metastatic noncolorectal gastrointestinal, breast and testicular tumours.

BACKGROUND: The indications for hepatectomy for colorectal or neuroendocrine metastases are becoming clear with increasing experience reported. For other primary diseases, however, the overall number of cases is relatively small, and it is more difficult to derive clear guidelines. This paper reviews the reported experience of hepatectomy for metastases from non-colorectal gastrointestinal primary cancers, breast cancer and testicular teratoma. The aim is to determine for each whether and under what circumstances hepatectomy is indicated. METHODS: A Medline search was used to identify papers reporting hepatectomy for metastases from non-colorectal gastrointestinal carcinomas, breast carcinomas and testicular teratomas. The data collected included the primary disease, the number of cases reported, the survival post-hepatectomy and any prognostic factors associated with outcome. RESULTS: Of the gastrointestinal malignancies, hepatectomy for gastric metastases yields a 5-year survival, roughly half that reported for colorectal disease, and further elucidation of prognostic factors would be desirable. Results were poor for other gastrointestinal malignancies. Good results were reported for breast and testicular teratoma. CONCLUSION: Of the non-colorectal gastrointestinal primaries, at present only hepatectomy for gastric metastases can be cautiously recommended. For nongastrointestinal primaries, hepatic metastases probably represent widespread dissemination even if occult, and therefore, hepatectomy may only be of use when effective adjuvant treatments are available.

Adult↗
PubMed2005

Who will do general surgery?

Advantages to patients of a single anaesthetic for more than one operation are obvious; attracting generalist surgeons, training them and ensuring they have adequate credentials remain hurdles.

Australia↗
PubMed2005

Transanal endoscopic microsurgery: a systematic review.

PURPOSE: The aim of this study was to systematically review the evidence relating to the safety and efficacy of transanal endoscopic microsurgery, a relatively new technique used to locally excise rectal tumors, compared with existing techniques such as anterior resections and abdominoperineal resections or local excisions. METHODS: We conducted a systematic review of comparative studies and case series of transanal endoscopic microsurgery from 1980 to August 2002. RESULTS: Three comparative studies (including one randomized, controlled trial) and 55 case series were included. The first area of study was the safety and efficacy of adenomas. In the randomized, controlled trial, no difference could be detected in the rate of early complications between transanal endoscopic microsurgery (10.3 percent) and direct local excision (17 percent) (relative risk, 0.61; 95 percent confidence interval, 0.29-1.29). Transanal endoscopic microsurgery resulted in less local recurrence (6/98; 6 percent) than direct local excision (20/90; 22 percent) (relative risk, 0.28; 95 percent confidence interval, 0.12-0.66). The 6 percent rate of local recurrence for transanal endoscopic microsurgery in this trial is consistent with the rates found in case series of transanal endoscopic microsurgery (median, 5 percent). The second area of study was the safety and efficacy of carcinomas. In the randomized, controlled trial, no difference could be detected in the rate of complications between transanal endoscopic microsurgery and direct local excision (relative risk for overall early complication rates, 0.56; 95 percent confidence interval, 0.22-1.42). No differences in survival or local recurrence rate between transanal endoscopic microsurgery and anterior resection could be detected in either the randomized, controlled trial (hazard ratio,1.02 for survival) or the nonrandomized, comparative study. There were 2 of 25 (8 percent) transanal endoscopic microsurgery recurrences in the randomized, controlled trial, but no figures were given for recurrence after anterior resection. In the case series, the median local recurrence rate for transanal endoscopic microsurgery was 8.4 percent, ranging from 0 percent to 50 percent. The third comparison was cost of the procedures. Transanal endoscopic microsurgery had both a lower recurrence rate and a lower cost than local excision or anterior resection for adenomas. Although the effectiveness of transanal endoscopic microsurgery could not be established for carcinomas, costs were lower than those for either anterior resection or abdominoperineal resection. CONCLUSIONS: The evidence regarding transanal endoscopic microsurgery is very limited, being largely based on a single relatively small randomized, controlled trial. However, transanal endoscopic microsurgery does appear to result in fewer recurrences than those with direct local excision in adenomas and thus may be a useful procedure for several small niches of patient types--e.g., for large benign lesions of the middle to upper third of the rectum, for T1 low-risk rectal cancers, and for palliative, not curative, use in more advanced tumors.

Anal Canal↗
PubMed2005

Interacting effects of preoperative information and patient choice in adaptation to colonoscopy.

PURPOSE: The aim of this study was to match patient information requirements by determining whether giving patients a choice for additional preprocedural audiovisual information modifies the effectiveness of this information on anxiety, worry, knowledge, and patient satisfaction. METHODS: Patients scheduled to undergo colonoscopy were approached one week before their procedure. All patients received an information leaflet during their standard preanesthetic clinic visit. Patients were randomly assigned to a choice or no-choice condition. Patients in the choice condition were free to watch or not watch the video, people in the no-choice condition were further randomized to watch or not watch the video. Measures of anxiety and worry were completed before watching the video. Anxiety, worry, knowledge, and satisfaction were measured one week later just before the colonoscopy. RESULTS: One hundred sixty-six patients completed the study. Of those patients randomized to the choice condition, 69 percent wanted to watch the video. Those who chose not to watch the video were significantly more worried on the day of their procedure. Consistent with current evidence, watching the video was associated with improvements in short-term knowledge (F(1,161) = 4.8, P = 0.03). There was, however, no significant effect of the choice or video conditions on anxiety or patient satisfaction. CONCLUSIONS: There appears to be no additional benefits in terms of patient outcomes by allowing patients to choose whether they want additional audiovisual information. We suggest that all patients undergoing colonoscopy would benefit from watching such an educational video in the week before their procedure.

Adaptation, Psychological↗
PubMed2005

How much liver resection is too much?

BACKGROUND: Hepatic failure occurring after liver resection carries a poor prognosis and is a complication dreaded by surgeons. Inadequate reserve in the remaining parenchyma leads to a steady decrease in liver function, inability to regenerate, and progression to liver failure. For this reason, many methods to quantify functional hepatic reserve have been developed. METHODS: This article reviews the main methods used in the assessment of hepatic reserve in patients undergoing hepatectomy and their use in operative decision making. RESULTS: A range of methods to categorically quantify the functional reserve of the liver have been developed, ranging from scoring systems (such as the Child-Pugh classification) to tests assessing complex hepatic metabolic pathways to radiological methods to assess functional reserve. However, no one method has or is ever likely to emerge as a single measure with which to dictate safe limits of resectability. CONCLUSIONS: In the future, the role of residual liver function assessment may be of most benefit in the routine stratification of risk, thus enabling both patient consent to be obtained and surgical procedure to be performed, with full information and facts regarding operative risks. However, there is no one single test that remains conclusively superior.

Female↗
PubMed2005

Systematic review of day-case laparoscopic Nissen fundoplication.

BACKGROUND: Laparoscopic Nissen fundoplication is increasingly being performed on a day-case basis. The aim of the present paper was to systematically review published data on day-case or ambulatory laparoscopic fundoplication and discuss the differing criteria for patient selection, postoperative management and patient outcomes presented in each series. METHODS: An optimally sensitive search strategy of subject headings and text words were used and the databases used included MEDLINE, PubMed and the Cochrane Library. All databases were searched from 1 January 1994 onwards. RESULTS: A total of seven papers were included in the present review, of which six were prospective single-cohort studies. Overall, there was large heterogeneity among the studies but with similar complication and readmission rates. CONCLUSIONS: Short-term outcomes for laparoscopic Nissen fundoplication in terms of complications and readmission rates are comparable to inpatient procedures. However there is a paucity of published data.

Ambulatory Surgical Procedures↗
PubMed2005

The role of pre-operative state-anxiety in the determination of intra-operative neuroendocrine responses and recovery.

OBJECTIVES: The psychophysiological model of adjustment to surgery predicts associations between (1) heightened pre-operative state-anxiety and intra-operative neuroendocrine responses, (2) neuroendocrine responses and complications; and (3) heightened pre-operative state-anxiety and post-operative recovery. The present study examined these associations. METHODS: Participants were 39 patients (mean age 71.9+/-6.1 years) undergoing elective carotid endarterectomy surgery under local anaesthesia. In the week prior to surgery, patients completed baseline measures of physical and mental functioning using the MOS 36-item Short-Form Health Survey (SF-36). In addition to this, they undertook a 24-hour urine save to measure cortisol and catecholamines. Measures of state-anxiety were completed on the evening prior to surgery. A second 24-hour urine save was started at the time of anaesthetic induction. Follow-up measures of physical and mental functioning were completed 1 month following surgery. All complications were recorded during hospitalization. RESULTS: There was a significant negative association between pre-operative state-anxiety and intra-operative cortisol (r=-.52, p<or=.001). Using hierarchical regression analysis, pre-operative state-anxiety accounted for 10% of the variance in intra-operative cortisol responses after controlling for medical and demographic factors. There were no significant associations between neuroendocrine responses and complications. Pre-operative state-anxiety was a significant determinant of poorer mental functioning following surgery, explaining 10% of the variance in scores after adjusting for baseline mental functioning. CONCLUSIONS: Results from this study show increasing pre-operative anxiety to be associated with lower intra-operative cortisol responses and poorer mental functioning 1 month following surgery.

Aged↗
PubMed2004

A systematic review of laparoscopic live-donor nephrectomy.

BACKGROUND: A systematic review was undertaken to assess the safety and efficacy of laparoscopic live-donor nephrectomy (LLDN) compared with open live-donor nephrectomy (OLDN). METHODS: Literature databases were searched from inception to March 2003 inclusive. Comparative studies of LLDN versus OLDN (randomized and nonrandomized) were included. RESULTS: There were 44 included studies, and the quality of the available evidence was average. There was only one randomized controlled trial and six nonrandomized comparative studies with concurrent controls identified. In terms of safety, for donors, there did not seem to be any distinct difference between the laparoscopic and open approaches. No donor mortality was reported for either procedure, and the complication rates were similar although the types of complications experienced differed between the two procedures. The conversion rate for LLDN to an open procedure ranged from 0% to 13%. In terms of efficacy, LLDN seemed to be a slower operation with longer warm ischemia times than OLDN, but this did not seem to have resulted in increased rates of delayed graft function for recipients. Donor postoperative recovery and convalescence seemed to be superior for LLDN, making it a potentially more attractive operation for living donors. Although in the short-term, graft function and survival did not seem to differ between the two techniques, long-term complication rates and allograft function could not be determined and further long-term follow-up is required. CONCLUSIONS: LLDN seems to be at least as safe and efficacious as OLDN in the short-term. However, it remains a technique in evolution. Further high-quality studies are required to resolve some of the outstanding issues surrounding its use, in particular, long-term follow-up of donor complications and recipient graft function and survival.

Humans↗
PubMed2004

The clinical risk score: emerging as a reliable preoperative prognostic index in hepatectomy for colorectal metastases.

HYPOTHESIS: The purpose of this study was to examine the validity of the clinical risk score (CRS), a prognostic tool developed by Fong et al, when translated to another center. DESIGN: This study assesses 5 independent preoperative prognostic criteria, nodal status of the primary lesion, disease-free interval, number of hepatic metastases, size of the largest metastasis, and preoperative carcinoembryonic antigen level, to determine a preoperative CRS for each patient included in the study. SETTING: The hepatobiliary unit of The Queen Elizabeth Hospital, Adelaide, South Australia. PATIENTS: Medical records of patients admitted to The Queen Elizabeth Hospital undergoing potentially curative hepatic resection for colorectal metastases during the period of July 1993 to April 2003 were included in the study. Main Outcome Measure The primary outcome measure of the study was survival. The calculated CRS was analyzed with respect to patient postoperative survival. RESULTS: During the 10-year period, 77 patients underwent hepatic resection. Overall survival rates for 1, 3, and 5 years were found to be 80.9%, 57.5%, and 42.3%, respectively. One- and 5-year survival rates for CRSs of 0 and 1 were found to be 93.8% and 72.5%, respectively; for scores of 2 and 3, 76.6% and 31.2%, respectively;and for scores of 4 and 5, 75% and 0%, respectively. No patient with a CRS greater than 3 survived more than 2 years. CONCLUSION: This study validates the CRS, finding it to be highly predictive of patient outcome and survival.

Adult↗
PubMed2004

Artificial liver support: potential to retard regeneration?

HYPOTHESIS: The concept of an "artificial liver" has been in development for over 40 years. Such devices aim to temporarily assume metabolic and excretory functions of the liver, with removal of potentially hepatotoxic substances, thereby clinically stabilizing patients and preventing deterioration while awaiting transplantation. If sufficient numbers of viable hepatocytes remain, regeneration and subsequent recovery of innate liver function may occur. However, these devices have not yet become part of routine clinical use. Much less is known regarding the effect such devices have, if any, on circulating cytokines and growth factors and the subsequent effects on the regenerating liver. If these devices remove or reduce factors known to promote regeneration, is the rate of regeneration retarded? Conversely, does the incorporation of hepatocytes into bioartificial support systems confer an advantage through the production of growth-promoting factors from these cultured hepatocytes?Data Sources, Extraction, and STUDY SELECTION: Data were obtained using PubMed search for reports involving liver support, extracorporeal circuits, dialysis, growth factors, and cytokines. Those reports specifically looking at the effect of artificial liver support on cytokines and growth factors are discussed. CONCLUSIONS: There is a paucity of information on the key events and substances involved in hepatic regeneration. In addition, there is a potential impact of liver support devices on the regeneration of substances associated with hepatic regeneration. Further study is needed.

Growth Substances↗
PubMed2004

Choice of surveillance after hepatectomy for colorectal metastases.

HYPOTHESIS: By review of a reported series, is outcome related to surveillance after hepatectomy? DESIGN: We reviewed English-language literature indexed on MEDLINE from January 1, 1990, through December 31, 2002. Indexing terms were combinations of hepatectomy, colorectal metastases, and recurrence with prognostic, repeat, follow-up, or surveillance. STUDY SELECTION: Studies containing any of the following data fields were included: recurrence after hepatectomy, rates of repeat hepatectomy, 5-year survival (overall or disease free) after hepatectomy (initial or repeat), posthepatectomy surveillance protocol, and detection of recurrence by surveillance modality. DATA EXTRACTION: Data were taken directly from a small number of articles and pooled across studies for analysis. We highlighted difficulties in assessing data quality and validity as a caveat to the interpretation of the results. RESULTS: The rate of recurrence after hepatectomy was 58%, and the rate of hepatic recurrence was 30%. Repeat hepatectomy was performed in 9.6% of cases. Five-year survivals after initial and repeat hepatectomy were 29% and 38%, respectively. Many studies did not report their surveillance protocols. For those that did, computed tomography or ultrasonography with carcinoembryonic antigen measurement most commonly formed the basis of surveillance. No data related surveillance techniques to the outcomes of recurrence detection, repeat hepatectomy, or survival. CONCLUSIONS: This review confirmed the value of repeat hepatectomy for recurrent disease, but uncovered no direct evidence supporting any surveillance modalities. Further studies are clearly needed, and approaches to these are discussed.

Carcinoembryonic Antigen↗
PubMed2004

Local ablation for unresectable liver tumors: is thermal best?

Hepatic resection remains the "gold standard" for patients with resectable disease. Nevertheless, for a variety of reasons this is not feasible for the majority of patients. A wide range of locally ablative techniques has been developed for use in these patients with the aim of improving survival. Unfortunately, as with many recent techniques in surgery, much of the development of these methods, and particularly their introduction clinically, has not been based on sound scientific data. The relative merits and limitations of the more commonly used techniques are discussed, although this lack of prospective, randomized data precludes firm conclusions to be drawn from many of the studies reported. By far the most popular methods now employed, thermal techniques have certain limitations, particularly when treating tumors adjacent to major vascular or biliary structures. The authors believe that this situation represents the "niche" for which ablative techniques may ultimately find their logical application, where a single awkwardly placed metastasis deems a patient unresectable. If such a metastasis can be completely and safely ablated, a potentially curative resection may then become a realistic option. The relatively new, nonthermal technique of hepatic electrolysis has been extensively studied and shown to be safe and effective in close proximity to major intrahepatic veins due to a subtle electrochemical action rather than a rapid "burn". This technique is discussed in the context of other, more traditional thermal methods of ablation.

Catheter Ablation↗
PubMed2004

Is laparoscopic intraoperative cholangiogram a matter of routine?

BACKGROUND: Intraoperative cholangiography during laparoscopic cholecystectomy reveals the anatomy of the biliary tree and any stones contained within it. The use of intraoperative cholangiography may be routine for all laparoscopic cholecystectomy. An alternative approach is a selective policy, performing intraoperative cholangiography only for those cases in which choledocholithiasis is suspected on clinical grounds, or those for which the anatomy appears unclear at operation. The literature pertaining to both approaches is reviewed, to delineate their respective merits. METHODS: Relevant articles in English were identified from the Medline database, and reviewed. RESULTS: The literature reviewed consisted of retrospective analyses. Overall the incidence of unsuspected retained stones was 4%, but only 15% of these would go on to cause clinical problems. The incidence of complete transection of the common bile duct was rare for both routine and selective intraoperative cholangiography policies, and did not differ between them. Rates of minor bile duct injury did not differ between groups, but was more likely to be recognized in the routine group than the selective (P = 0.01). CONCLUSIONS: Routine intraoperative cholangiography yields very little useful clinical information over and above that which is obtained with selective policies. Large numbers of unnecessary intraoperative cholangiography are performed under routine intraoperative cholangiography policy, and therefore a selective policy is advocated.

Bile Ducts↗