Individual distribution of muscle hypertrophy among hamstring muscle heads: Adding muscle volume where you need is not so simple

PURPOSE

The aim of this study was to determine whether a 9-week resistance training program based on high load (HL) versus low load combined with blood flow restriction (LL-BFR) induced a similar (i) distribution of muscle hypertrophy among hamstring heads (semimembranosus, SM; semitendinosus, ST; and biceps femoris long head, BF) and (ii) magnitude of tendon hypertrophy of ST, using a parallel randomized controlled trial.

METHODS

A total of 45 participants were randomly allocated to one of three groups: HL, LL-BFR, and control (CON). Both HL and LL-BFR performed a 9-week resistance training program composed of seated leg curl and stiff-leg deadlift exercises. Freehand 3D ultrasound was used to assess the changes in muscle and tendon volume.

RESULTS

The increase in ST volume was greater in HL (26.5 ± 25.5%) compared to CON (p = 0.004). No difference was found between CON and LL-BFR for the ST muscle volume (p = 0.627). The change in SM muscle volume was greater for LL-BFR (21.6 ± 27.8%) compared to CON (p = 0.025). No difference was found between HL and CON for the SM muscle volume (p = 0.178).There was no change in BF muscle volume in LL-BFR (14.0 ± 16.5%; p = 0.436) compared to CON group. No difference was found between HL and CON for the BF muscle volume (p = 1.0). Regarding ST tendon volume, we did not report an effect of training regimens (p = 0.411).

CONCLUSION

These results provide evidence that the HL program induced a selective hypertrophy of the ST while LL-BFR induced hypertrophy of SM. The magnitude of the selective hypertrophy observed within each group varied greatly between individuals. This finding suggests that it is very difficult to early determine the location of the hypertrophy among a muscle group.

Ways of preventing surgeon burnout

In surgical practice, numerous sources of stress (stressors) are unpredictable, two examples being daily workload and postoperative complications. They may help to explain surgeon burnout, of which the prevalence (34 to 53%) has been the subject of many studies. That said, even though assessments are legion, recommended solutions have been few and far between, especially insofar as by nature and training, surgeons are disinclined to interest themselves in burnout, which they are prone to consider as something experienced by "others". The objective of this attempt at clarification is to identify in the literature the strategies put forward in view of avoiding surgeon burnout, and to assess the impact of this phenomenon not only on the surgeon's professional and personal entourage, but also on patient safety. Prevention-based strategies, many of them focused on modifiable stressors, will be detailed.

Resectability of bilobar liver tumours after simultaneous portal and hepatic vein embolization versus portal vein embolization alone: meta-analysis

BACKGROUND

Many patients with bi-lobar liver tumours are not eligible for liver resection due to an insufficient future liver remnant (FLR). To reduce the risk of posthepatectomy liver failure and the primary cause of death, regenerative procedures intent to increase the FLR before surgery. The aim of this systematic review is to provide an overview of the available literature and outcomes on the effectiveness of simultaneous portal and hepatic vein embolization (PVE/HVE) versus portal vein embolization (PVE) alone.

METHODS

A systematic literature search was conducted in PubMed, Web of Science, and Embase up to September 2022. The primary outcome was resectability and the secondary outcome was the FLR volume increase.

RESULTS

Eight studies comparing PVE/HVE with PVE and six retrospective PVE/HVE case series were included. Pooled resectability within the comparative studies was 75 per cent in the PVE group (n = 252) versus 87 per cent in the PVE/HVE group (n = 166, OR 1.92 (95% c.i., 1.13-3.25)) favouring PVE/HVE (P = 0.015). After PVE, FLR hypertrophy between 12 per cent and 48 per cent (after a median of 21-30 days) was observed, whereas growth between 36 per cent and 67 per cent was reported after PVE/HVE (after a median of 17-31 days). In the comparative studies, 90-day primary cause of death was similar between groups (2.5 per cent after PVE versus 2.2 per cent after PVE/HVE), but a higher 90-day primary cause of death was reported in single-arm PVE/HVE cohort studies (6.9 per cent, 12 of 175 patients).

CONCLUSION

Based on moderate/weak evidence, PVE/HVE seems to increase resectability of bi-lobar liver tumours with a comparable safety profile. Additionally, PVE/HVE resulted in faster and more pronounced hypertrophy compared with PVE alone.

Laparoscopic versus open resection of intrahepatic cholangiocarcinoma: nationwide analysis

BACKGROUND

The relevance of laparoscopic resection of intrahepatic cholangiocarcinoma (ICC) remains debated. The aim of this study was to compare laparoscopic (LLR) and open (OLR) liver resection for ICC, with specific focus on textbook outcome and lymph node dissection (LND).

METHODS

Patients undergoing LLR or OLR for ICC were included from two French, nationwide hepatopancreatobiliary surveys undertaken between 2000 and 2017. Patients with negative margins, and without transfusion, severe complications, prolonged hospital stay, readmission or death were considered to have a textbook outcome. Patients who achieved both a textbook outcome and LND were deemed to have an adjusted textbook outcome. OLR and LLR were compared after propensity score matching.

RESULTS

In total, 548 patients with ICC (127 LLR, 421 OLR) were included. Textbook-outcome and LND completion rates were 22.1 and 48.2 per cent respectively. LLR was independently associated with a decreased rate of LND (odds ratio 0.37, 95 per cent c.i. 0.20 to 0.69). After matching, 109 patients remained in each group. LLR was associated with a decreased rate of transfusion (7.3 versus 21.1 per cent; P = 0.001) and shorter hospital stay (median 7 versus 14 days; P = 0.001), but lower rate of LND (33.9 versus 73.4 per cent; P = 0.001). Patients who underwent LLR had lower rate of adjusted TO completion than patients who had OLR (6.5 versus 17.4 per cent; P = 0.012).

CONCLUSION

The laparoscopic approach did not substantially improve quality of care of patients with resectable ICC.

Impact of cirrhosis in patients undergoing laparoscopic liver resection in a nationwide multicentre survey

BACKGROUND

The aim was to analyse the impact of cirrhosis on short-term outcomes after laparoscopic liver resection (LLR) in a multicentre national cohort study.

METHODS

This retrospective study included all patients undergoing LLR in 27 centres between 2000 and 2017. Cirrhosis was defined as F4 fibrosis on pathological examination. Short-term outcomes of patients with and without liver cirrhosis were compared after propensity score matching by centre volume, demographic and tumour characteristics, and extent of resection.

RESULTS

Among 3150 patients included, LLR was performed in 774 patients with (24·6 per cent) and 2376 (75·4 per cent) without cirrhosis. Severe complication and mortality rates in patients with cirrhosis were 10·6 and 2·6 per cent respectively. Posthepatectomy liver failure (PHLF) developed in 3·6 per cent of patients with cirrhosis and was the major cause of death (11 of 20 patients). After matching, patients with cirrhosis tended to have higher rates of severe complications (odds ratio (OR) 1·74, 95 per cent c.i. 0·92 to 3·41; P = 0·096) and PHLF (OR 7·13, 0·91 to 323·10; P = 0·068) than those without cirrhosis. They also had a higher risk of death (OR 5·13, 1·08 to 48·61; P = 0·039). Rates of cardiorespiratory complications (P = 0·338), bile leakage (P = 0·286) and reoperation (P = 0·352) were similar in the two groups. Patients with cirrhosis had a longer hospital stay than those without (11 versus 8 days; P = 0·018). Centre expertise was an independent protective factor against PHLF in patients with cirrhosis (OR 0·33, 0·14 to 0·76; P = 0·010).

CONCLUSION

Underlying cirrhosis remains an independent risk factor for impaired outcomes in patients undergoing LLR, even in expert centres.

Original Study: Transjugular Intrahepatic Portosystemic Shunt as a Bridge to Abdominal Surgery in Cirrhotic Patients

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS) has been suggested to reduce portal hypertension-associated complications in cirrhotic patients undergoing abdominal surgery. The aim of this study was to compare postoperative outcome in cirrhotic patients with and without specific preoperative TIPS placement, following elective extrahepatic abdominal surgery.

METHODS

Patients were retrospectively included from 2005 to 2016 in four centers. Patients who underwent preoperative TIPS (n = 66) were compared to cirrhotic control patients without TIPS (n = 68). Postoperative outcome was analyzed using propensity score with inverse probability of treatment weighting analysis.

RESULTS

Overall, colorectal surgery accounted for 54% of all surgical procedure. TIPS patients had a higher initial Child-Pugh score (6[5-12] vs. 6[5-9], p = 0.043) and received more beta-blockers (65% vs. 22%, p < 0.001). In TIPS group, 56 (85%) patients managed to undergo planned surgery. Preoperative TIPS was associated with less postoperative ascites (hazard ratio = 0.330 [0.140-0.780]). Severe postoperative complications (Clavien-Dindo > 2) and 90-day mortality were similar between TIPS and no-TIPS groups (18% vs. 23%, p = 0.392, and 7.5% vs. 7.8%, p = 0.644, respectively).

CONCLUSIONS

Preoperative TIPS placement yielded an 85% operability rate with satisfying postoperative outcomes. No significant differences were found between TIPS and no-TIPS groups in terms of severe postoperative complications and mortality, although TIPS patients probably had worse initial portal hypertension.

Autologous dental pulp mesenchymal stem cells for inferior third molar post-extraction socket healing: A split-mouth randomised clinical trial

Background

Since the discovery of adult mesenchymal stem cells extensive research has been conducted to determine their mechanisms of differentiation and effectiveness in cell therapy and regenerative medicine.

Material and Methods

To assess the efficacy of autologous dental pulp mesenchymal stem cells delivered in a collagen matrix for post-extraction socket healing, a single-centre, double-blind, randomised, split-mouth, controlled clinical trial was performed. Both impacted mandibular third molars were extracted from 32 patients. Dental pulp was collected and dissociated; the resulting cell suspension, obtained by centrifugation, was incorporated into a resorbable collagen matrix and implanted in 32 experimental post-extraction sockets. Collagen matrices alone were implanted in 32 contralateral, control post-extraction sockets. Two neuroradiologists independently assessed the extent of bone repair at 6 months after the extractions. Computed tomography (CT, Philips Brilliance) and an advanced display platform (IntelliSpace Portal) was used to record extraction socket density, expressed as Hounsfield units (HU) and height (mm) of the distal interdental bone septum of the second molar. Measurements at 6 months post-extraction were compared with measurements obtained immediately after extraction. Data were analysed with the statistical program STATA 14.

Results

Two patients dropped out of the study. The final sample consisted of 22 women and 8 men (mean age, 23 years; range: 18–30 years). Clinical, radiological, and surgical characteristics of impacted third molars of the control and experimental groups were homogeneous. Measurements obtained by the two neuroradiologists showed agreement. No significant differences were found in the extent of bone repair during analyses of density (p=0.4203 neuroradiologist 1; p=0.2525 neuroradiologist 2) or interdental septum height (p=0.2280 neuroradiologist 1; p=0.4784 neuroradiologist 2).

Conclusions

In our clinical trial, we were unable to demonstrate that autologous dental pulp mesenchymal stem cells reduce socket bone resorption after inferior third molar extraction.

Key words:Clinical trial, autologous, pulpal stem cells, extraction socket healing.

Can we refine the management of blunt liver trauma?

AIM

To describe the management of blunt liver injury and to study the potential relation between delayed complications, type of trauma mechanisms and liver lesions.

PATIENTS AND METHODS

This is a retrospective single center study including 116 consecutive patients admitted with blunt liver injury between 2007 and 2015.

RESULTS

Initial CT-scan identified an active bleeding in 33 (28%) patients. AAST (American Association for the Surgery of Trauma) grade was 1 to 3 in 82 (71%) patients and equal to 5 in 15 (13%) patients. Eighty (69%) patients had NOM, with a success rate of 96%. Other abdominal organ lesions were associated to invasive initial management. A follow-up CT-scan was useful to detect hepatic and extra-hepatic complications (46 complications in 80 patients), even without clinical or biological abnormalities. Subsequent hepatic complications such as bleeding, pseudo aneurysms, biloma and biliary peritonitis developed in 15 patients and were associated with the severity of blunt liver injury according to AAST classification (3.7±1.0 vs. 3.0±1.1, P=0.010). Total biliary complications occurred in 13 patients and were significantly more frequently observed in patients with injury of central segments 1, 4 and 9 (69% vs. 36%, P=0.033).

CONCLUSIONS

Non-operative management is possible in most blunt liver injury with a success rate of 96%. A systematic CT-scan should be advocated during follow-up, especially when AAST grade is equal or superior to 3. Biliary complications should be suspected when lesions involve segments 1, 4 and 9.

Efficacy of amoxicillin and amoxicillin/clavulanic acid in the prevention of infection and dry socket after third molar extraction. A systematic review and meta-analysis

Background

Prophylactic use of amoxicillin and amoxicillin/clavulanic acid, although controversial, is common in routine clinical practice in third molar surgery.

Material and Methods

Our objective was to assess the efficacy of prophylactic amoxicillin with or without clavulanic acid in reducing the incidence of dry socket and/or infection after third molar extraction. We conducted a systematic review and meta-analysis consulting electronic databases and references in retrieved articles. We included double-blind placebo-controlled randomized clinical trials published up to June 2015 investigating the efficacy of amoxicillin with or without clavulanic acid on the incidence of the aforementioned conditions after third molar extraction. Relative risks (RRs) were estimated with a generic inverse-variance approach and a random effect model using Stata/IC 13 and Review Manager Version 5.2. Stratified analysis was performed by antibiotic type.

Results

We included 10 papers in the qualitative review and in the quantitative synthesis (1997 extractions: 1072 in experimental groups and 925 in controls, with 27 and 74 events of dry socket and/or infection, respectively). The overall RR was 0.350 (p< 0.001; 95% CI 0.214 to 0.574). We found no evidence of heterogeneity (I2=0%, p=0.470). The number needed to treat was 18 (95% CI 13 to 29). Five studies reported adverse reactions (RR=1.188, 95% CI 0.658 to 2.146, p =0.567). The RRs were 0.563 for amoxicillin (95% CI 0.295 to 1.08, p=0.082) and 0.215 for amoxicillin/clavulanic acid (95% CI 0.117 to 0.395, p<0.001).

Conclusions

Prophylactic use of amoxicillin does not significantly reduce the risk of infection and/or dry socket after third molar extraction. With amoxicillin/clavulanic acid, the risk decreases significantly. Nevertheless, considering the number needed to treat, low prevalence of infection, potential adverse reactions to antibiotics and lack of serious complications in placebo groups, the routine prescription of amoxicillin with or without clavulanic acid is not justified.

Key words:Meta-analysis, amoxicillin, infection, removal, dry socket, third molar.

Medical complications following splenectomy

Splenectomy is attended by medical complications, principally infectious and thromboembolic; the frequency of complications varies with the conditions that led to splenectomy (hematologic splenectomy, trauma, presence of portal hypertension). Most infectious complications are caused by encapsulated bacteria (Meningococcus, Pneumococcus, Hemophilus). These occur mainly in children and somewhat less commonly in adults within the first two years following splenectomy. Post-splenectomy infections are potentially severe with overwhelming post-splenectomy infection (OPSI) and this justifies preventive measures (prophylactic antibiotics, appropriate immunizations, patient education) and demands prompt antibiotic management with third-generation cephalosporins for any post-splenectomy fever. Thromboembolic complications can involve both the caval system (deep-vein thrombophlebitis, pulmonary embolism) and the portal system. Portal vein thrombosis occurs more commonly in patients with myeloproliferative disease and cirrhosis. No thromboembolic prophylaxis is recommended apart from perioperative low molecular weight heparin. However, some authors choose to prescribe a short course of anti-platelet medication if the post-splenectomy patient develops significant thrombocytosis. Thrombosis of the portal or caval venous system requires prolonged warfarin anticoagulation for 3 to 6 months. Finally, some studies have suggested an increase in the long-term incidence of cancer in splenectomized patients.

Modified Appleby procedure for borderline resectable/locally advanced distal pancreatic adenocarcinoma: A major procedure for selected patients

BACKGROUND

In distal pancreatic ductal adenocarcinoma (PDAC), distal pancreatectomy with en bloc splenectomy and celiac axis resection (DP-CAR) can allow curative resection in case of tumor extension to celiac axis.

METHODS

From 2008 to 2013, of 102 patients with localized distal PDAC, 7 patients with celiac axis involvement were planned to undergo DP-CAR with curative intent. All patients received neoadjuvant treatment followed by preoperative coil embolization to enlarge collateral arterial pathways, except if a replaced right hepatic artery arising from superior mesenteric artery was present and sufficient for the blood supply. We herein analyzed indications, technique and outcomes of DP-CAR.

RESULTS

After neoadjuvant treatment and arterial embolization, two patients experienced tumor progression and were not operated while five underwent DP-CAR. No patient required arterial reconstruction. Postoperative mortality was nil, but morbidity was 100%, mainly represented by pancreatic fistula. Postoperatively, there was a complete pain relief but chronic diarrhea was observed in all patients. Resections were R0 in three patients. One operated patient was alive and disease free at 60 months whereas median overall survival of patients who underwent resection was 24 months.

CONCLUSIONS

DP-CAR for borderline resectable/locally advanced distal PDAC is associated with high morbidity and mixed long-term functional results. Neoadjuvant treatment may prevent from unnecessary surgery for patients with progressive disease and may facilitate resection with acceptable long-term survival.

Risk factors and consequences of conversion in laparoscopic major liver resection

BACKGROUND

Although recent reports have suggested potential benefits of the laparoscopic approach in patients requiring major hepatectomy, it remains unclear whether conversion to open surgery could offset these advantages. This study aimed to determine the risk factors for and postoperative consequences of conversion in patients undergoing laparoscopic major hepatectomy (LMH).

METHODS

Data for all patients undergoing LMH between 2000 and 2013 at two tertiary referral centres were reviewed retrospectively. Risk factors for conversion were determined using multivariable analysis. After propensity score matching, the outcomes of patients who underwent conversion were compared with those of matched patients undergoing laparoscopic hepatectomy who did not have conversion, operated on at the same centres, and also with matched patients operated on at another tertiary centre during the same period by an open laparotomy approach.

RESULTS

Conversion was needed in 30 (13·5 per cent) of the 223 patients undergoing LMH. The most frequent reasons for conversion were bleeding and failure to progress, in 14 (47 per cent) and nine (30 per cent) patients respectively. On multivariable analysis, risk factors for conversion were patient age above 75 years (hazard ratio (HR) 7·72, 95 per cent c.i. 1·67 to 35·70; P = 0·009), diabetes (HR 4·51, 1·16 to 17·57; P = 0·030), body mass index (BMI) above 28 kg/m(2) (HR 6·41, 1·56 to 26·37; P = 0·010), tumour diameter greater than 10 cm (HR 8·91, 1·57 to 50·79; P = 0·014) and biliary reconstruction (HR 13·99, 1·82 to 238·13; P = 0·048). After propensity score matching, the complication rate in patients who had conversion was higher than in patients who did not (75 versus 47·3 per cent respectively; P = 0·038), but was not significantly different from the rate in patients treated by planned laparotomy (79 versus 67·9 per cent respectively; P = 0·438).

CONCLUSION

Conversion during LMH should be anticipated in patients with raised BMI, large lesions and biliary reconstruction. Conversion does not lead to increased morbidity compared with planned laparotomy.

Pyogenic liver abscess: an unusual cause

A 60-year-old female patient was referred for a massive pyogenic liver abscess that had been initially treated with percutaneous drainage and antibiotics. CT-scan showed a foreign body in the hepatic pedicle, adjacent to the right portal vein: a fishbone. After 6 weeks of medical management with antibiotics, the foreign body was removed laparoscopically. The presence of a foreign body should be sought in cases of pyogenic liver abscess, especially if no other intra-abdominal cause has been found or if the abscess fails to resolve with medical treatment alone.

Hepatic angiomyolipoma: what management?

An 80-year-old woman was referred for the surgical treatment of a 110-mm right hepatic tumor. The biopsy revealed an adenoma, and a right hepatectomy was performed. Histopathology indicated a major fat component with epitheliod cells, immunoreactivity for HMB45, Melan A, and smooth muscle actin, describing a hepatic epithelioid angiomyolipoma (AML). The AML belongs to the group of tumors with a Perivascular Epithelioid Cell differentiation. Its diagnosis is based on imaging and biopsy, and therefore might be difficult. Hepatic AML are mainly benign tumors; however, some tend to behave in a malignant manner. In case of histological proof, close clinical and radiological monitoring can be proposed if its size is less than 5 cm and no pejorative histological features are found. Nevertheless, follow-up is still required if resection is performed in search of recurrence or metastatic spread.

Minimal portal vein stenosis is a promising preconditioning in living donor liver transplantation in porcine model

BACKGROUND & AIMS

The main hindrance in promoting living donor liver transplantation remains the morbi-mortality risk for the donor. Considering the opposed remodeling influence of portal and hepatic artery flows, our working hypothesis was to identify a lobar portal vein stenosis capable of inducing a contralateral liver mass compensatory enlargement, without the downstream ipsilateral atrophic response.

METHODS

Twenty-four pigs entered this study. Six of them were used to establish hemodynamic changes following a progressive left portal vein (LPV) stenosis, in blood flow, pressure and vessel diameter of the LPV, main portal vein and hepatic artery. Sixteen pigs were divided into 4 groups: sham operated animals, 20% LPV stenosis, 50% LPV stenosis, and 100% LPV stenosis. Daily liver biopsies were collected until post-operative day 5 to investigate liver regeneration and atrophy (Ki67, STAT3, LC3, and activated caspase 3) according to the degree of LPV stenosis. Finally, changes in liver volumetry after 20% LPVS were investigated.

RESULTS

A 20% LPV stenosis led to dilatation of the hepatic artery and a subsequent four-fold increase in hepatic arterial flow. Concomitantly, liver regeneration was triggered in the non-ligated lobe and the cell proliferation peak, 5 days after surgery, was comparable to that obtained after total LPV ligation. Moreover, 20% LPV stenosis preconditioning did not induce left liver atrophy contrary to 50 and 100% LPV stenosis.

CONCLUSIONS

A 20% LPV stenosis seems to be the adequate preconditioning to get the remnant liver of living donor ready to take on graft harvesting without atrophy of the future graft.

Long-term consequences of bile duct injury after cholecystectomy

Late complications arising after bile duct injury (BDI) include biliary strictures, hepatic atrophy, cholangitis and intra-hepatic lithiasis. Later, fibrosis or even secondary biliary cirrhosis and portal hypertension can develop, enhanced by prolonged biliary obstruction associated with recurrent cholangitis. Secondary biliary cirrhosis resulting in associated hepatic failure or digestive tract bleeding due to portal hypertension is a substantial risk factor for morbidity and mortality after bile duct repair. Parameters that determine the management of late complications of BDI include the type of biliary injury, associated vascular injury, hepatic atrophy, the presence of intra-hepatic strictures or lithiasis, repetitive infectious complications, the quality of underlying parenchyma (fibrosis, secondary biliary cirrhosis) and the presence of portal hypertension. Endoscopic drainage is indicated for patients with uncontrolled acute sepsis, patients at high operative risk, patients with cirrhosis who are not eligible for liver transplantation and patients who have previously undergone several attempts at repair. Roux-en-Y hepaticojejunostomy, whether de novo or as an iterative repair, is the technique of reference for post-cholecystectomy BDI. Hepatic resection is indicated in only rare instances, mainly in case of extended hilar stricture, multiple stone retention in one sector of the liver or in patients for whom the repair is deemed technically difficult. Liver transplantation is indicated only in exceptional circumstances, when secondary biliary cirrhosis is associated with liver failure and portal hypertension.

[The use of temporary implants in prosthetic dentistry]

Temporary implants can offer a worthwhile contribution to a patient's comfort during the integration of conventional implants or during the maturation of bone grafts. Although temporary implants are not intended for osseointegration, survival rates are sufficiently high for them to be functional during several months. Fixed prostheses which are attached to temporary implants perform better than removable prostheses which more quickly lead to the loosening and loss of these temporary implants.

Crackling versus continuumlike dynamics in brittle failure

We study how the loading rate, specimen geometry, and microstructural texture select the dynamics of a crack moving through an heterogeneous elastic material in the quasistatic approximation. We find a transition, fully controlled by two dimensionless variables, between dynamics ruled by continuum fracture mechanics and crackling dynamics. Selection of the latter by the loading, microstructure, and specimen parameters is formulated in terms of scaling laws on the power spectrum of crack velocity. This analysis defines the experimental conditions required to observe crackling in fracture. Beyond failure problems, the results extend to a variety of situations described by models of the same universality class, e.g., the dynamics in wetting or of domain walls in amorphous ferromagnets.

Fabrication of CdZnTe Strip Detectors for Large Area Arrays

A CdZnTe strip detector large area array (∼ 60 cm2 with 36 detectors) with capabilities for high resolution imaging and spectroscopy has been built as a prototype for a space flight gamma ray burst instrument. The detector array also has applications in nuclear medical imaging. Two dimensional orthogonal strip detectors with 100 μm pitch have been fabricated and tested. Details for the array design, fabrication and evaluation of the detectors will be presented.

Performance of Prototype Segmented CdZnTe Arrays

The Burst and All Sky Imaging Survey (BASIS) is a proposed mission to provide ∼3 arc second locations of approximately 90 Gamma-Ray Bursts (GRBs) per year. The BASIS coded aperture imaging system requires a segmented detector plane able to detect the interaction position of (10 - 150 keV) photons to less than 100 μm. To develop prototype detector arrays with such fine position resolution we have fabricated many 15 mm × 15 mm × 2 mm 100 μm pitch CdZnTe strip detectors. We have assembled these fine pitch CdZnTe strip detectors into prototype 2 × 2 and 6 × 6 element arrays read out by ASIC electronics. The assembly and electronics readout of the 6 × 6 flight prototype array will be discussed, and preliminary data illustrating the uniformity and efficiency of the array will be presented.

Liver resection after downstaging hepatocellular carcinoma with sorafenib

Background. Sorafenib is a molecular-targeted therapy used in palliative treatment of advanced hepatocellular carcinoma in Child A patients. Aims. To address the question of sorafenib as neoadjuvant treatment. Methods. We describe the cases of 2 patients who had surgery after sorafenib. Results. The patients had a large hepatocellular carcinoma in the right liver with venous neoplastic thrombi (1 in the right portal branch, 1 in the right hepatic vein). After 9 months of sorafenib, reassessment showed that tumours had decreased in size with a necrotic component. A right hepatectomy with thrombectomy was performed, and histopathology showed 35% to 60% necrosis. One patient had a recurrence after 6 months and had another liver resection; they are both recurrence-free since then. Conclusion. Sorafenib can downstage hepatocellular carcinoma and thus could represent a bridge to surgery. It may be possible to select patients in good general condition with partial regression of the tumour with sorafenib for a treatment in a curative intent.

Ruptured liver cell adenoma in man: great fortune in misfortune

Liver cell adenoma is mostly known as a tumour affecting women with long-term use of contraceptive hormones. Its incidence in men is very low, and particularly few cases of acute complications are related in the literature. We report the case of a 44-year-old man presenting with a life-threatening rupture of a hepatic tumour, successfully treated in emergency with primary endovascular embolization, followed by hepatectomy, once stabilized. The pathological findings were fortunately consistent with the diagnosis of liver-cell adenoma. To our knowledge, it is the first case reported in a man treated by a combined interventional radiological and surgical approach.

[Abdominal cystic tumor revealing lymphangioleiomyomatosis]

We report the case of a 39 year-old woman with many years of intermittent abdominal pain who was found to have cystic masses evocative of cystic lymphangioma involving the posterior mediastinal and retroperitoneum. Worsening abdominal pain led to a recommendation for laparoscopic unroofing and decompression of the cysts. During the postoperative period, hemorrhagic shock required reintervention with excision of the tumoral mass. Pathologic examination revealed lymphangioleiomyomatosis (LAM). On the 15th postoperative day, the patient developed a chylopneumothorax which required prolonged chest tube drainage. The presence of multiple polycystic lesions in the pulmonary parenchyma supported the diagnosis of diffuse LAM with primary extrapulmonary presentation. This diagnosis should be considered preoperatively since it modifies the treatment: a complete excision of the cystic lesions seems to be necessary in order to prevent bleeding and lymphatic extravasation.

A short γ-ray burst apparently associated with an elliptical galaxy at redshift z = 0.225

Gamma-ray bursts (GRBs) come in two classes: long (> 2 s), soft-spectrum bursts and short, hard events. Most progress has been made on understanding the long GRBs, which are typically observed at high redshift (z approximately 1) and found in subluminous star-forming host galaxies. They are likely to be produced in core-collapse explosions of massive stars. In contrast, no short GRB had been accurately (< 10'') and rapidly (minutes) located. Here we report the detection of the X-ray afterglow from--and the localization of--the short burst GRB 050509B. Its position on the sky is near a luminous, non-star-forming elliptical galaxy at a redshift of 0.225, which is the location one would expect if the origin of this GRB is through the merger of neutron-star or black-hole binaries. The X-ray afterglow was weak and faded below the detection limit within a few hours; no optical afterglow was detected to stringent limits, explaining the past difficulty in localizing short GRBs.

A giant γ-ray flare from the magnetar SGR 1806–20

Two classes of rotating neutron stars-soft gamma-ray repeaters (SGRs) and anomalous X-ray pulsars-are magnetars, whose X-ray emission is powered by a very strong magnetic field (B approximately 10(15) G). SGRs occasionally become 'active', producing many short X-ray bursts. Extremely rarely, an SGR emits a giant flare with a total energy about a thousand times higher than in a typical burst. Here we report that SGR 1806-20 emitted a giant flare on 27 December 2004. The total (isotropic) flare energy is 2 x 10(46) erg, which is about a hundred times higher than the other two previously observed giant flares. The energy release probably occurred during a catastrophic reconfiguration of the neutron star's magnetic field. If the event had occurred at a larger distance, but within 40 megaparsecs, it would have resembled a short, hard gamma-ray burst, suggesting that flares from extragalactic SGRs may form a subclass of such bursts.

Sentinel Node Biopsy in Head and Neck Cancer: Preliminary Results of a Multicenter Trial

BACKGROUND

The aim was to determine the reliability and reproducibility of sentinel node biopsy (SNB) as a staging tool in head and neck squamous cell carcinoma (HNSCC) for T1/2 clinically N0 patients by means of a standardized technique.

METHODS

Between June 1998 and June 2002, 227 SNB procedures have been performed in HNSCC cases at six centers. One hundred thirty-four T1/2 tumors of the oral cavity/oropharynx in clinically N0 patients were investigated with preoperative lymphoscintigraphy (LSG), intraoperative use of blue dye/gamma probe, and pathological evaluation with step serial sectioning and immunohistochemistry, with a follow-up of at least 12 months. In 79 cases SNB alone was used to stage the neck carcinoma, and in 55 cases SNB was used in combination with an elective neck dissection (END).

RESULTS

In 125/134 cases (93%) a sentinel node was identified. Of 59 positive nodes, 57 were identified with the intraoperative gamma probe and 44 with blue dye. Upstaging of disease occurred in 42/125 cases (34%): with hematoxylin-eosin in 32/125 (26%) and with additional pathological staging in 10/93 (11%). The sensitivity of the technique with a mean follow-up of 24 months was 42/45 (93%). The identification of SNB for floor of mouth (FOM) tumors was 37/43 (86%), compared with 88/91 (97%) for other tumors. The sensitivity for FOM tumors was 12/15 (80%), compared with 30/30 (100%) for other tumor groups.

CONCLUSION

SNB can be successfully applied to early T1/2 tumors of the oral cavity/oropharynx in a standardized fashion by centers worldwide. For the majority of these tumors the SNB technique can be used alone as a staging tool.

Microchemical transformation of bioactive glass particles of narrow size range, a 0-24 months study

Previous studies demonstrated the capacity of bioactive glass particles of narrow size range (300-355 microm, Biogran) to stimulate bone tissue formation without contact with pre-existing bone tissue. Chemical interactions between the bioactive glass and the surrounding tissue fluids caused the glass transformation. This study quantifies the time-dependent transformation process. Particles were implanted in the jaws of beagle dogs and resected after 1, 2, 3, 6, 12 and 24 months. Microchemical analysis was performed using a scanning electron microscope equipped with an energy dispersive X-ray analysis system. After one month, Na-ions were leached out and the particles transformed into two layers. In the center, a Si-rich gel was found on the outer surface, a Ca- and P-rich shell. After two months, the concentration levels of the outer Ca- and P-rich shell remained. In the center the Si-concentration decreased and the Ca and P concentration increased. After three months, Si disappeared completely from the center of the particle, while the Ca and P concentration increased. At one and two years, the Ca and P concentrations in the transformed particles equalled those of bone tissue, turning the transformed particle into a chemical equivalent of the bone mineral phase.

Identification of the atomic structure of the fivefold surface of an icosahedral Al-Pd-Mn quasicrystal: helium diffraction and scanning tunneling microscopy studies

High resolution He diffraction and scanning tunneling microscopy images of the fivefold surface of a single-grain i-AlPdMn quasicrystal are obtained showing an almost perfect quasicrystal order. Observed configurations can be identified within the framework of polyhedral models. The terrace terminations are found to be Al-rich planes and successions of step heights agree with distances between dense Al planes in the model. This shows the ability of recent 6D polyhedral models to describe real quasicrystalline atomic configurations.

Temporomandibular arthroscopy: a retrospective clinical study (1995-1999) of 61 cases

OBJECTIVES

A study was made of the internal derangements of the temporomandibular joint (TMJ) in order to: (a) determine the coincidence between the preoperative clinical diagnosis and imaging findings and the intraoperative arthroscopic observations, (b) establish the efficacy of arthroscopic treatment, and (c) evaluate the complications of the procedure.

DESIGN

A descriptive and retrospective clinical study (1995-1999) of 61 TMJ arthroscopies was design.

RESULTS

Coincidence was recorded between the clinical diagnosis and arthroscopic findings in 66.6% of cases, and the imaging diagnostic observations (magnetic resonance imaging) in 71.6%. The surgical outcome in terms of movement range was considered excellent (aperture > 40 mm) in 19 patients (42.2%), good (30-40 mm) in 19 (42.2%), and poor (< 30 mm) in 7 patients (15.6%). Postoperative pain assessment was in turn excellent (absence of pain) in 27 patients (60%), good (significant pain remission) in 9 (20%) and poor (persistent or increased pain) in 9 patients (20%). There were 7 complications and all healed without sequelae.

CONCLUSIONS

The global results indicate an excellent or good movement range in 84.2%, with either no postoperative pain or only minimum pain in 81.4% of cases. Consequently, if arthroscopy is used for a precise indication in an adequate patient, it can improve the quality of life of individuals with TMJ pathology in situations where conservative procedures have failed.

Knee joint arthroplasty in a patient with haemophilia A and high inhibitor titre using recombinant factor VIIa (NovoSeven): a new case report and review of the literature

Elective orthopaedic surgery is regularly withheld from patients with haemophilia and high inhibitor titre despite the presence of severe arthropathy and urgent medical need. A knee joint arthroplasty was performed in a patient with severe haemophilia A and a high inhibitor titre using recombinant factor VIIa (rFVIIa) as the sole coagulation factor. There was no abnormal bleeding during surgery although an increased blood loss through surgical drains did occur during the first 6 h postoperatively. Rehabilitation was started on day 1 and continued for 3 months. Walking commenced on day 4. After 1 year of follow-up, the clinical outcome of surgery was considered excellent with no pain, knee mobility at 0-5-90 degrees, and an International Knee Society score of 95/100. No rFVIIa-associated side-effects or thrombotic complications were reported. In conclusion, knee joint arthroplasty is now an option for haemophilia patients with a high inhibitor titre. An international review of all available data on elective orthopaedic surgery in inhibitor patients is required so that the optimal treatment regime can be defined and the short- and long-term risk-benefit ratio of surgery compared to that of noninhibitor patients.