The effect of visual feedback of body parts on pain perception: A systematic review of clinical and experimental studies.

The aim of this systematic review was to evaluate the effect of visual feedback techniques on pain perception by analysing the effect of normal-sized, magnified or minified visual feedback of body parts on clinical and experimentally-induced pain. Databases searched: Medline, Embase, PsychInfo, PEDro, CINAHL, CENTRAL and OpenSIGLE. Studies investigating pain patients and pain-free participants exposed to experimentally-induced pain were analysed separately. Risk of bias was assessed and data were meta-analysed. Thirty four studies were included. A meta-analysis of clinical data favoured mirror visual feedback (six trials; mean difference = -13.06 mm; 95% CI = -23.97, -2.16). Subgroup analysis favoured mirror visual feedback when used as a course of treatment (three trials; mean difference = -12.76 mm; 95% CI = -24.11, -1.40) and when used for complex regional pain syndrome for complex regional pain syndrome (three trials; standard mean difference = -1.44; 95% CI = -1.88, -0.99). There is insufficient evidence to determine differences between normal-sized view and a size-distorted view of the limb. Mirror visual feedback was not superior to object view or direct view of the hand for reducing experimental pain in pain-free participants. There were inconsistencies in study findings comparing normal-sized reflection of a body part and a reflection of an object, or a magnified or minified reflection. There is tentative evidence that mirror visual feedback can alleviate pain when delivered as a course of treatment, and for patients with complex regional pain syndrome. It was not possible to determine whether normal-sized, magnified or minified visual feedback of body parts affects pain perception because of contradictory findings in primary studies. SIGNIFICANCE: It was not possible to determine whether normal-sized, magnified or minified visual feedback of body parts affected pain perception in clinical or experimental settings because of contradictory findings in primary studies. This emphasizes the need for higher quality studies.

Changing the size of a mirror-reflected hand does not affect pain perception: A repeated measures study on healthy human participants.

BACKGROUND: Studies suggest that observing magnified and minified body parts using mirrors, lenses and virtual reality may affect pain perception. However, the direction of effect varies between studies. The aim of the present study was to evaluate the effect of observing a normal-sized, magnified and minified reflection of a hand on perceptual embodiment and contact-heat stimuli. METHODS: Participants (n = 46) observed a normal-sized, magnified and minified reflection of the hand and a no-reflection condition while performing synchronized finger movements for 3 min (adaptive phase). Measurements of embodiment were taken before adaptive phase, pre- and post-contact-heat stimuli. RESULTS: There were no differences in pain threshold nor tolerance between reflection and no-reflection conditions. Altering the size of the reflection of the hand did not affect estimates of pain threshold nor tolerance. The temperature for warm detection threshold was lower when participants were observing the magnified reflection of the hand compared with the no-reflection condition. Perceptual embodiment of the reflection of the hand was stronger after an adaptive phase with visuo-motor feedback, and the painful stimuli did not weaken the perceptual experience. CONCLUSION: Observing a reflection of the hand in front of a mirror did not alter heat pain threshold nor tolerance when compared with a no-reflection condition, and altering the size of the reflection did not affect pain perception. Researchers and clinicians using visual feedback techniques may consider including an adaptive phase with visuo-motor feedback to facilitate embodiment of the viewed body part. SIGNIFICANCE: An adaptive phase with visuo-motor feedback enhances the perceptual experience of embodiment of a reflection of a hand and a painful stimulus does not weaken the experience. This should be considered when using visual feedback techniques for pain management.

Sportsmans Groin: The Inguinal Ligament and the Lloyd Technique.

Groin pain is a catch all phrase used to define a common set of symptoms that affect many individuals. It is a common condition affecting sportsmen and women (1, 2) and is often referred to as the sportsman groin (SG). Multiple surgical operations have been developed to treat these symptoms yet no definitive imaging modalities exist to diagnose or predict prognosis. This article aims to discuss the anatomy of the groin, suggest a biomechanical pathophysiology and outline a logical surgical solution to treat the underlying pathology. A systematic clinical and imaging approach with inguinal ligament and pubic specific MRI assessment, can result in accurate selection for intervention. Close correlation with clinical examination and imaging in series is recommended to avoid misinterpretation of chronic changes in athletes.

Right upper quadrant pain and raised alkaline phosphatase is not always a hepatobiliary problem.

Right upper quadrant pain is a common presenting complaint to the general and hepatobiliary surgical team. Differential diagnoses include gallstones, cholecystitis, liver and pancreatic pathology. A 64-year-old man presented to our general surgical unit with right upper quadrant pain and deranged liver function tests. He underwent ultrasonography several times as well as magnetic resonance cholangiopancreatography (MRCP) in pursuit of hepatobiliary pathology. However, it was the identification of an empyema on MRCP that led to computed tomography of the thorax and the eventual discovery of the cause of the pain: a paraspinal abscess causing T10/T11 discitis. Right upper quadrant pain and deranged liver function tests justify hepatobiliary investigation. Nevertheless, after several negative tests, the differential diagnoses should be broadened and referred pain considered.

A European survey on the aetiology, investigation and management of the "sportsman's groin".

INTRODUCTION: A sportsman's groin has no accepted definition or consensus on treatment. The aim of this study was to assess current opinion among a large body of European surgeons using an online survey. METHODS: An online questionnaire comprising 16 multiple-choice questions was sent by email to general surgeons in Europe. The survey was live from the 6th to 30th September 2011. RESULTS: In total 143 responses were received. One hundred and six respondents (74 %) expressed experience in managing this condition. The majority (91 %) managed <26 cases per year. Posterior wall weakness (53 %), pubic tendinitis (43 %), nerve entrapment (37 %) and conjoint tendon injury (36 %) were the commonest aetiological factors described. Preferred diagnostic investigations were ultrasound of the groin (44 %) and MRI of the pelvis (29 %). The most common initial treatment (91 % of respondents) was conservative measures (rest and analgesia) for a maximum of 6-month period. When surgery was undertaken, Lichtenstein repair (29 %), TEP (27 %), TAPP (20 %), and posterior wall repair (21 %) were the commonest procedures. The majority (95 %) of respondents would not offer bilateral surgery for those presenting with unilateral groin pain. CONCLUSIONS: Most European surgeons see <26 cases of "sportsman's groin" per year, which is in keeping with the low incidence of this condition. There remains wide variation in its investigation and management, which reflects the differences in opinion on its aetiology. The majority of surgeons agree that surgery is not the only treatment option available, but there is little consensus on the optimal management.

'Treatment of the sportsman's groin': British Hernia Society's 2014 position statement based on the Manchester Consensus Conference.

INTRODUCTION: The aim was to produce a multidisciplinary consensus to determine the current position on the nomenclature, definition, diagnosis, imaging modalities and management of Sportsman's groin (SG). METHODS: Experts in the diagnosis and management of SG were invited to participate in a consensus conference held by the British Hernia Society in Manchester, U.K. on 11-12 October 2012. Experts included a physiotherapist, a musculoskeletal radiologist and surgeons with a proven track record of expertise in this field. Presentations detailing scientific as well as outcome data from their own experiences were given. Records were made of the presentations with specific areas debated openly. RESULTS: The term 'inguinal disruption' (ID) was agreed as the preferred nomenclature with the term 'Sportsman's hernia' or 'groin' rejected, as no true hernia exists. There was an overwhelming agreement of opinion that there was abnormal tension in the groin, particularly around the inguinal ligament attachment. Other common findings included the possibility of external oblique disruption with consequent small tears noted as well as some oedema of the tissues. A multidisciplinary approach with tailored physiotherapy as the initial treatment was recommended with any surgery involving releasing the tension in the inguinal canal by various techniques and reinforcing it with a mesh or suture repair. A national registry should be developed for all athletes undergoing surgery. CONCLUSIONS: ID is a common condition where no true hernia exists. It should be managed through a multidisciplinary approach to ensure consistent standards and outcomes are achieved.

Can itch-related visual stimuli alone provoke a scratch response in healthy individuals?

BACKGROUND: The sensation of itch and the scratch response elicited by application of histamine are enhanced by itch-related visual cues in people with existing skin conditions and, to a lesser extent, in healthy controls. OBJECTIVES: We tested whether visual cues alone could generate feelings of itch and provoke a scratch response in healthy volunteers. A secondary aim was to assess whether the content of some pictures evoked these sensations more effectively. METHODS: Thirty participants viewed static images that were either itch-related (e.g. ants, fleas or skin conditions) or neutral (e.g. butterflies or healthy skin). These were further separated by picture type into 'skin contact' (e.g. ants crawling on the hand or a butterfly on a finger), 'skin response' (e.g. scratching an insect bite or washing the hands) or 'context only' (e.g. viewing midges or birds flying). RESULTS: The sensation of itch was successfully generated using itch-related pictures, with higher self-reports of itch in answer to the questions 'How itchy do you feel?' and 'How itchy do you think the person in the picture feels?', compared with viewing neutral pictures (P<0·001), and these measures correlated (P≤ 0·003). Participants also scratched themselves more when viewing itch-related pictures than when viewing neutral ones (P<0·001). The interaction with picture type was significant, with more scratching behaviour recorded when viewing pictures depicting others scratching (P=0·01). CONCLUSIONS: This study demonstrates the impact of visual cues in eliciting sensations of itch and provoking a scratch response, and may provide behavioural evidence linking contagious itch to the mirror neuron system.

Microwave ablation of the liver: a description of lesion evolution over time and an investigation of the heat sink effect.

AIM: Microwave ablation has been successfully used to treat unresectable liver tumours for many years. However, despite its widespread use, there seems to be a relative paucity of experimental data regarding lesion evolution and the effects of any surrounding vasculature on ablation morphology. The aim of this study was to investigate the principal pathological changes in the liver following microwave ablation, in particular the heat sink effect. In addition we carefully reviewed the available literature to provide an overview of all relevant pathological studies. METHODS: Microwave ablation was carried out on male rats at various distances from the hilum. Histological (H&E) and immunocytochemical (caspase 3) analyses of the lesion were performed at various time points; 0, 4, 24, 48  hours, 2 weeks and 1 month. A literature review was carried out using Medline, Embase and the Cochrane database to identify all relevant histological studies. RESULTS: The lesion underwent complete coagulative necrosis and was extremely regular at the ablation edge with no evidence of any influence from surrounding blood vessels at all time points. H&E and caspase 3 results were consistent and microwave caused little collateral damage outside the intended ablation zone. CONCLUSION: This study suggests that microwave ablation is extremely concise and is minimally affected by the heat sink effect. Comparative investigations with other treatment modalities are required.

Experimental application of electrolysis in the treatment of liver and pancreatic tumours: principles, preclinical and clinical observations and future perspectives.

BACKGROUND: Electrolytic ablation (EA) is a treatment that destroys tissues through electrochemical changes in the local microenvironment. This review examined studies using EA for the treatment of liver and pancreatic tumours, in order to define the characteristics that could endow the technique with specific advantages compared with other ablative modalities. METHODS: Literature search of all studies focusing on liver and pancreas EA. RESULTS: A specific advantage of EA is its safety even when conducted close to major vessels, while a disadvantage is the longer ablation times compared to more frequently employed techniques. Bimodal electric tissue ablation modality combines radiofrequency with EA and produced significant larger ablation zones compared to EA or radiofrequency alone, reducing the time required for ablation. Pancreatic EA has been investigated in experimental studies that confirmed similar advantages to those found with liver ablation, but has never been evaluated on patients. Furthermore, few clinical studies examined the results of liver EA in the short-term but there is no appropriate follow-up to confirm any survival advantage. CONCLUSIONS: EA is a safe technique with the potential to treat lesions close to major vessels. Specific clinical studies are required to confirm the technique's safety and eventually demonstrate a survival advantage.

The effects of radiofrequency ablation on the hepatic parenchyma: histological bases for tumor recurrences.

BACKGROUND: This review examines histological modifications obtained after liver radiofrequency ablation (RFA). METHODS: A literature search has been undertaken for all pre-clinical and clinical studies involving RFA and in which ablation zones have been excised for a complete histological examination. RESULTS: Two main histological areas are present, a central zone of coagulative necrosis and a peripheral rim of congestion and extravasation. Both corresponded to specific microscopic characteristics that evolved over time and that are influenced by the proximity of patent vessels and the liver perfusion status. Viable cells are not present in the central zone but have been described in the ischemic peripheral rim where they survive the ischemia and inflammation process. These correspond in clinical studies to residual viable tumor cells that lead to failure of the procedure. CONCLUSIONS: Histological changes following RFA are complex and interactions take place at both a cellular and tissue level. Changes in the peripheral zone must be considered in future studies in order to extend the volume of reliable tumor destruction and increase the effectiveness of the procedure.

Cryotherapy of the liver: a histological review.

INTRODUCTION: Cryotherapy has been largely used in the past for palliation of unresectable liver tumors, but high local recurrence rates and peculiar systemic complications have determined its progressive abandonment. This review analyzes the histological changes produced to provide the basis for the local recurrences. MATERIALS AND METHODS: A detailed literature search was performed on studies focusing on liver cryotherapy. Included were only those that described the histological characteristics in detail. RESULTS: A total of 22 studies were found, one clinical and the others in-vivo animal studies. Similar to other ablative techniques, cryotherapy produces a lesion which is composed by a central zone of coagulative necrosis surrounded with a transitional inflammatory zone. The lesion's dimensions and morphology are influenced by numerous factors including the probe temperature, diameter, the duration of freezing time, fast cooling rate, slow thawing rate, the number of freezing cycles and the inflow occlusion (Pringle maneuver). The temporal evolution is consistent across studies and leads to a progressive inflammatory invasion of the necrosis with definitive fibrotic substitution. CONCLUSIONS: Lesions obtained after cryotherapy seem similar and behave as those obtained after other techniques of liver ablation. However, controversial areas still exist and include the optimum number of freeze thaw cycles, the place of inflow occlusion, the potential corrupting effects of intra-lesional or proximal blood vessels on ablation morphology. The influence of these factors on the local recurrences are still not fully understood.

Microwave ablation for unresectable hepatic tumours: clinical results using a novel microwave probe and generator.

BACKGROUND: Microwave ablation is an in situ method of tumour destruction used to treat patients with unresectable liver tumours. A new microwave generator and probe, designed to deliver high energy into solid tumours quickly has been developed at our institution. We report the results of its use in patients with unresectable liver tumours treated by a single surgeon in a single institution. METHODS: Thirty-one patients with 89 unresectable liver tumours were recruited into the study and underwent microwave ablation in a single procedure. RESULTS: There were no post-operative complications. At a median of 24 months post ablation, 15 patients were alive with 7 patients disease free. At a median of 26 months, 8 patients were alive with tumour recurrence but only 1 with local recurrence. The remaining 7 patients with recurrence were found to have new disease at locations remote from the ablation site. Fourteen patients died of disease progression at a median survival of 15 months, with only 1 patient with local and remote tumour recurrence. Of the total numbers of tumours treated (n=89), a local tumour recurrence rate of 2% was observed. Overall median survival was 29 months with 3 year survival of 40%. DISCUSSION: Microwave tissue ablation using this novel generator and probe has a low local recurrence and complication rate. Overall survival is comparable to alternative ablation modalities and its ability to treat, even large tumours, with a single insertion of the probe makes it an extremely attractive treatment option.

Liver ablation techniques: a review.

BACKGROUND: Ablation techniques for unresectable liver carcinomas have evolved immensely since their introduction. Results of studies involving these techniques are restricted to reports of patient case series, which are often not presented in a standardised manner. This review aims to summarise the major studies in ablation technologies and present them in a way that may make comparison between the major modalities easier. METHODS: All major databases (Medline, Cochrane, Embase and Pubmed) were searched for studies using microwave, radiofrequency or cryoablation to treat unresectable liver tumours. Only studies with at least 30 patients and 3-year follow-up were included. Complication, recurrence and survival rates of all studies are summarised and presented. RESULTS AND CONCLUSION: It is difficult to compare ablation modalities, as probe design and energy sources have evolved rapidly over the last decade. Ablation offers an invaluable palliative option and in some cases it may offer rates of cure approaching that of surgical resection with lower morbidity and mortality. Perhaps the time has come, therefore, for prospective large-scale randomised control trials to take place comparing ablation modalities to each other and surgical resection.

A fuller understanding of pancreatic neuroendocrine tumours combined with aggressive management improves outcome.

BACKGROUND: Neuroendocrine tumours of the pancreas (PNETs) represent 1-2% of all pancreatic tumours. The terms 'islet cell tumours' and 'carcinoids' of the pancreas should be avoided. The aim of this review is to offer an overview of the history and diagnosis of PNETs followed by a discussion of the available treatment options. METHODS: A search on PubMed using the keywords 'neuroendocrine', 'pancreas' and 'carcinoid' was performed to identify relevant literature over the last 30 years. RESULTS: The introduction of a revised classification of neuroendocrine tumours by the World Health Organisation (WHO) in 2000 significantly changed our understanding of and approach to the management of these tumours. Advances in laboratory and radiological techniques have also led to an increased detection of PNETs. Surgery remains the only treatment that offers a chance of cure with increasing number of non-surgical options serving as beneficial adjuncts. The better understanding of the behaviours of PNETs together with improvements in tumour localisation has resulted in a more aggressive management strategy with a concomitant improvement in symptom palliation and a prolongation of survival. CONCLUSION: Due to their complex nature and the wide range of therapeutic options, the involvement of specialists from all necessary disciplines in a multidisciplinary team setting is vital to provide optimal treatment of this disease.

Prediction of mortality in acute pancreatitis: a systematic review of the published evidence.

OBJECTIVE: In this review, we focus on studies that examined such prognostic indices in relation to predicting a fatal outcome from pancreatitis. SUMMARY BACKGROUND DATA: Acute pancreatitis (AP) is a common emergency, and early identification of high-risk patients can be difficult. For this reason, a plethora of different prognostic variables and scoring systems have been assessed to see if they can reliably predict the severity of pancreatitis and/or subsequent mortality. METHODS: All studies that focused on AP, including retrospective series and prospective trials, were retrieved and analysed for factors that could influence mortality. Articles that analysed factors influencing the severity of the disease or the manifestation of disease-related complications were excluded. RESULTS: 58 articles meeting the inclusion criteria were identified. Among the various factors investigated, APACHE II seemed to have the highest positive predictive value (69%). However, most prognostic variables and scores showed high negative predictive values but suboptimal values for positive predictive power. CONCLUSIONS: Despite the proliferation of scoring systems for grading AP, none are ideal for the prediction of mortality. With the exception of the APACHE II, the other scores and indexes do not have a high degree of sensitivity, specificity and predictive values.

Cytokine response to ischemia/reperfusion injury in an ex vivo perfused porcine liver model.

BACKGROUND: We evaluated the degree of inflammatory response after ischemia/reperfusion injury by an extracorporeal normothermic autologous hemoperfusion of porcine livers. MATERIALS AND METHODS: Livers explanted from 7 pigs were perfused extracorporeally at 39 degrees C with autologous blood. Serum samples were obtained hourly until 6 hours from the beginning of reperfusion and assayed for 9 different cytokines. RESULTS: Significant elevations in interleukin 6 (IL-6) and IL-8 were noted following reperfusion (P < .001), with both demonstrating an increase which followed a sigmoid curve; other cytokines that were assessed showed no significant change. CONCLUSIONS: The ex vivo model excludes the liver from the influence of external systemic factors such as hormones, the autonomic nervous system, and other regulatory molecules produced elsewhere in the body, allowing the response to the ischemia/reperfusion injury to be studied in isolation and in considerable detail. Although this study examined a relatively short period, the increases in only IL-6 and IL-8 suggested that these are important molecules in the early phase after reperfusion.

The inguinal release procedure for groin pain: initial experience in 73 sportsmen/women.

OBJECTIVE: To assess the impact of the laparoscopic inguinal release procedure with mesh reinforcement on athletes with groin pain. DESIGN: Prospective cohort study. SETTING: Private sector. PATIENTS: Professional and amateur sportsmen/women undergoing the inguinal release for groin pain. MAIN OUTCOME MEASUREMENTS: Change in patient's symptoms, functional limitation and time to resuming sporting activity following surgery. RESULTS: 73 sportsmen/women underwent laparoscopic inguinal release in the study period, 37 (51%) of whom were professionals. 95% were male with a median age of 30 years. Following operation, patients returned to light training at a median of 1 week, full training at 3 weeks (professionals-2 weeks) and playing competitively at 4 weeks (professionals-3 weeks). 74% considered themselves match-fit by 4 weeks (84% of professionals). Following surgery, there was a highly significant improvement in frequency of pain, severity of pain and functional limitation in both the whole cohort and professional group. 88% reported a return to full fitness at follow-up, with 73% reporting complete absence of symptoms. 97% of the cohort thought the operation had improved their symptoms. CONCLUSIONS: This study shows that the laparoscopic inguinal release procedure may be effective in the treatment of a subgroup of athletes with groin pain.

A comparative histological evaluation of the ablations produced by microwave, cryotherapy and radiofrequency in the liver.

AIMS: Complete tumour cell death is necessary for any ablative technique to be successful. Microwave tissue ablation (MTA), radiofrequency (RF) and cryotherapy (CT) are three methods of destroying liver tumours in situ. Unlike MTA, RF and CT rely on conduction of the thermal insult for their cytotoxicity, potentially affecting lesion uniformity. The aim of this study was to compare the uniformity of demarcation of lesions induced by MTA, RF and CT in the rat liver. METHODS: Twenty-one rats were assigned to each of the three ablative modalities. RESULTS: All specimens exhibited macroscopically well-demarcated lesions. Microscopically, the most clearly delineated lesions were induced by MTA with no intra-lesional viable hepatocytes or peri-vascular survival. All vessels and bile ducts had undergone complete necrosis. CT specimens showed more prominent inflammation at the lesion edge than MTA and peri-vascular hepatocyte survival within the ablated volumes. RF showed hepatocyte survival in the ablated area and conspicuous peri-vascular hepatocyte survival with evidence of a very irregular lesion edge. Cell viability was only assessed with H&E staining and not immunocytochemically. CONCLUSION: Unlike RF and CT, MTA induced microscopically well-demarcated lesions, with no intralesional hepatocyte survival. Intralesional cell survival in RF and CT may be due to the relatively prolonged treatment times needed, allowing thermal energy to dissipate via blood flow. This is known as the heat sink effect and may contribute to the high local recurrence rates following treatment of larger tumours with RF and CT.

Surgical treatment of combined hepatic and pulmonary colorectal cancer metastases.

AIMS: Surgical resection of combined hepatic and pulmonary metastases remains controversial in light of limited supportive evidence. This study aimed to audit our initial experience with this aggressive surgical strategy. METHODS: Between 1997 and 2006 we assessed 19 patients with colorectal cancer metastases for combined liver and lung metastasectomy, of whom 16 patients underwent surgery. We retrospectively reviewed perioperative and survival data. RESULTS: Synchronous liver metastases were present in three out of 16 patients at time of diagnosis of the primary tumour, and one out of 16 patients had synchronous lung and liver metastases with the primary tumour. Of those 12 patients who developed metachronous metastases five patients developed liver metastases first, one patient developed pulmonary metastases first, and six patients developed synchronous liver and lung metastases. Thirty nine operations were performed on 16 patients. The median hospital stay was 5.5 (2-10) days for the pulmonary and 7 (1-23) days for the hepatic resections. There were no in-hospital deaths. Chemotherapy was given to five patients prior to metastasectomy and nine received adjuvant chemotherapy following metastasectomy. Median survival from diagnosis of metastatic disease was 44 months (8-87 months). Estimated 1-year survival from diagnosis of metastatic disease was 94%, estimated 5-year survival was 20%. CONCLUSION: We believe an aggressive but selective surgical approach to combined hepatic and pulmonary colorectal metastases is justified by limited resource requirements and encouraging survival.