Mind the gap - Small bowel obstruction due to preperitoneal herniation following laparoscopic inguinal hernia repair - A case report.

INTRODUCTION AND IMPORTANCE: Inguinal hernia repair is a very frequent operation in general and visceral surgery worldwide. The laparo-endoscopic approaches such as TAPP have gained increasing acceptance among specialists and many consider them as standard of care due to perioperative safety and excellent postoperative results. Knowledge of specific complications after minimally invasive inguinal hernia surgery, however, is important for the successful management of these patients. CASE PRESENTATION: We herein present the case of a 75-year-old female patient who electively underwent laparoscopic repair of combined inguinal and femoral hernia. During the postoperative course a small bowel obstruction occurred requiring emergency re-laparoscopy revealing a preperitoneal herniation of small bowel through a peritoneal defect. CLINICAL DISCUSSION: Small bowel obstruction due to preperitoneal herniation of small bowel through a peritoneal defect after laparoscopic hernia repair is extremely rare. In such cases, emergency laparoscopic revision is necessary to avoid bowel ischaemia. Adequate closure of the peritoneum during the primary procedure along with the necessary attention to detail seems mandatory to avoid preperitoneal herniation after TAPP. CONCLUSION: Inadequate peritoneal closure after TAPP may lead to preperitoneal herniation of the small bowel leading to postoperative intestinal obstruction. All hernia surgeons should be aware of this rare, but potentially life-threatening complication and should close all peritoneal defects with greatest care and accuracy.

Ordering CT pulmonary angiography to exclude pulmonary embolism: defense versus evidence in the emergency room.

PURPOSE: To identify reasons for ordering computed tomography pulmonary angiography (CTPA), to identify the frequency of reasons for CTPA reflecting defensive behavior and evidence-based behavior, and to identify the impact of defensive medicine and of training about diagnosing pulmonary embolism (PE) on positive results of CTPA. METHODS: Physicians in the emergency department of a tertiary care hospital completed a questionnaire before CTPA after being trained about diagnosing PE and completing questionnaires. RESULTS: Nine hundred patients received a CTPA during 3 years. For 328 CTPAs performed during the 1-year study period, 140 (43 %) questionnaires were completed. The most frequent reasons for ordering a CTPA were to confirm/rule out PE (93 %), elevated D-dimers (66 %), fear of missing PE (55 %), and Wells/simplified revised Geneva score (53 %). A positive answer for "fear of missing PE" was inversely associated with positive CTPA (OR 0.36, 95 % CI 0.14-0.92, p = 0.033), and "Wells/simplified revised Geneva score" was associated with positive CTPA (OR 3.28, 95 % CI 1.24-8.68, p = 0.017). The proportion of positive CTPA was higher if a questionnaire was completed, compared to the 2-year comparison period (26.4 vs. 14.5 %, OR 2.12, 95 % CI 1.36-3.29, p < 0.001). The proportion of positive CTPA was non-significantly higher during the study period than during the comparison period (19.2 vs. 14.5 %, OR 1.40, 95 % CI 0.98-2.0, p = 0.067). CONCLUSION: Reasons for CTPA reflecting defensive behavior-such as "fear of missing PE"-were frequent, and were associated with a decreased odds of positive CTPA. Defensive behavior might be modifiable by training in using guidelines.

Effect of Q-angle on patellar positioning and thickness of knee articular cartilages.

The purpose of the present study was to investigate whether an increased quadriceps angle (Q-angle) has an effect on patellar positioning and/or the thickness of the medial and lateral tibiofemoral and patellofemoral articular cartilage and menisci, in a group of young asymptomatic individuals. These individuals were detected in a previous study with a decreased anatomical cross-sectional area of the vastus medialis and lateralis as a result of an increased Q-angle. Patellar positioning and the thickness of the articular cartilages were determined in 19 asymptomatic male individuals with high Q-angle (HQ-angle) (18.5° ± 2.6°) using magnetic resonance imaging (MRI). Seventeen male counterparts with low Q-angle (10.1° ± 1.9°) were used for comparison. The position of the patella was determined by measuring the sulcus angle, the lateral patella tilt, the patella-lateral condyle index and the bisect offset (BSO) with the quadriceps relaxed. The BSO, was also measured with the quadriceps under maximum isometric voluntary contraction. The thickness of the articular cartilages of the lateral and medial femoral condyles, the tibial condyles, the patellar facets and the menisci were also measured. Our data revealed that healthy individuals with HQ-angle are unlikely to demonstrate any changes in the position of the patella and/or the thickness of the knee articular cartilages. The decreased anatomical area of the vastus medialis and an almost equally atrophied vastus lateralis, which was previously observed in this group of individuals may prevent in part the misalignment of the patella and early wear of the tibiofemoral and patellofemoral articular cartilages.

MR motility imaging in Crohn's disease improves lesion detection compared with standard MR imaging.

OBJECTIVE: To evaluate retrospectively in patients with Crohn's disease (CD) if magnetic resonance (MR) motility alterations correlate with CD typical lesions leading to an increased detection rate. METHODS: Forty patients with histologically proven CD underwent MR enterography (MRE), including coronal cine sequences (cine MRE), in addition to the standard CD MR protocol. Two blinded readings were performed with and without cine MRE. Locations presenting motility alterations on the cine sequences were analysed on standard MRE for CD-related lesions. This was compared with a second reading using the standard clinical MRE protocol alone. RESULTS: The number of lesions localised by cine MRE and identified on standard MRE compared with standard MRE alone were 35/24 for wall thickening (p = 0.002), 24/20 for stenoses (p = 0.05), 17/11 for wall layering (p = 0.02), 5/3 for mucosal ulcers (p = 0.02) and 21/17 for the comb sign (p = 0.05). Overall, cine MRE detected 35 more CD-specific findings than standard MRE alone (124/89; p = 0.007) and significantly more patients with CD-relevant MR findings (34/28; p = 0.03). CONCLUSION: CD lesions seem to be associated with motility changes and this leads to an increased lesion detection rate compared with standard-MRE imaging alone.

Enhancement of liver parenchyma after injection of hepatocyte-specific MRI contrast media: a comparison of gadoxetic acid and gadobenate dimeglumine.

PURPOSE: To compare enhancement of liver parenchyma in MR imaging after injection of hepatocyte-specific contrast media. MATERIALS AND METHODS: Patients (n = 295) with known/suspected focal liver lesions randomly received 0.025 mmol gadoxetic acid/kg body weight or 0.05 mmol gadobenate dimeglumine/kg body weight by means of bolus injection. MR imaging was performed before and immediately after injection, and in the delayed phase at approved time points (20 min after injection of gadoxetic acid and 40 min after injection of gadobenate dimeglumine). The relative liver enhancement for the overall population and a cirrhotic subgroup was compared in T1-weighted GRE sequences. An independent radiologist performed signal intensity measurements. Enhancement ratios were compared using confidence intervals (CIs). RESULTS: The relative liver enhancement in the overall population was superior with gadoxetic acid (57.24%) versus gadobenate dimeglumine (32.77%) in the delayed-imaging phase. The enhancement ratio between the contrast media was statistically significant at 1.75 (95% CI: 1.46-2.13). In the delayed phase, the enhancement of cirrhotic liver with gadoxetic acid (57.00%) was comparable to that in the overall population. Enhancement with gadobenate dimeglumine was inferior in cirrhotic liver parenchyma (26.85%). CONCLUSION: In the delayed, hepatocyte-specific phase, liver enhancement after injection of gadoxetic acid was superior to that obtained with gadobenate dimeglumine.

Pretransplant pulmonary hypertension and long-term allograft right ventricular function.

BACKGROUND: Graft right ventricular (RV) function is compromised directly posttransplant, especially in heart transplantation (HTx) recipients with pretransplant pulmonary hypertension (PH). Graft RV size and systolic function, and the effect of the recipient's pulmonary haemodynamics on the graft extracellular matrix are not well characterised in the patients long-term after HTx. AIM: Comparison of RV size and systolic function in HTx recipients' long-term posttransplant stratified by the presence of pretransplant PH. METHODS: HTx survivors >or=2 years posttransplant were divided into group I without pretransplant PH (pulmonary vascular resistance, PVR <2.5 Wood units, n=37) and group II with PH (PVR >or=2.5 Wood units, n=16). RV size and systolic function were measured using cardiac magnetic resonance imaging (CMR). The collagen content was assessed in septal endomyocardial biopsies obtained at HTx and at study inclusion. RESULTS: Mean posttransplant follow-up was 5.2+/-2.9 years (group I) and 4.9+/-2.2 years (group II) (p=0.70). PVR was 1.5+/-0.6 vs 4.1+/-1.7 Wood units pretransplant (p<0.001), and 1.2+/-0.5 vs 1.3+/-0.5 Wood units at study inclusion (p=0.43). Allograft RV size and systolic function were similar in both groups (p always >or=0.07). Collagen content at transplantation and at follow-up were not different (p always >or=0.60). CONCLUSION: Posttransplant normalisation of pretransplant PH is associated with normal graft RV function long-term after HTx.

The role of the sinuses of Valsalva in aortic root flow dynamics and aortic root surgery: evaluation by magnetic resonance imaging.

BACKGROUND AND AIM OF THE STUDY: Combined replacement of the aortic valve and ascending aorta using a composite graft represents the standard treatment for dilated aortic root with concomitant structural damage of the aortic valve, especially when the aortic valve cannot be preserved. Unfortunately, hemodynamic changes associated with prosthetic replacement of the aortic root have not been fully elucidated. The study aim was to compare hemodynamics within the replaced aortic root using either a prosthetic vascular graft with bulges mimicking the sinuses of Valsalva and including a stented pericardial valve, or a straight xenopericardial conduit and a stentless porcine valve. METHODS: Between July 2004 and March 2006, a total of 35 patients (mean age 65.2 years: range: 32-80 years) was enrolled into the present study. Aortic root replacement was performed in nine patients with a Valsalva graft (Gelweave Valsalva; Vascutek, Renfrewshire, UK) including a stented pericardial valve, and in 19 patients with a xenopericardial conduit containing a stentless porcine valve. All patients underwent postoperative magnetic resonance imaging (MRI). A control group of seven patients allowed for comparison with native aortic root hemodynamics. RESULTS: Maximum flow-velocity above the aortic valve as one marker of compliance of the aortic root was slightly higher in patients with a Valsalva graft compared to native aortic roots (1.9 m/s versus 1.3 m/s, p = 0.001), but was significantly lower than in patients with the xenopericardial graft without neo-sinuses (1.3 m/s versus 2.4 m/s, p < 0.001). CONCLUSION: The pre-shaped bulges in the prosthetic Valsalva graft effectively mimic the native sinuses of Valsalva, improve compliance of the aortic root, and result in a more physiologic flow pattern, as demonstrated by postoperative MRI.

Quadriceps cross-sectional area changes in young healthy men with different magnitude of Q angle.

Knee pain and dysfunction have been often associated with an ineffective pull of the patella by the vastus medialis (VM) relative to the vastus lateralis (VL), particularly in individuals with knee joint malalignment. Such changes in muscular behavior may be attributed to muscle inhibition and/or atrophy that precedes the onset of symptoms. The aim of this study was to investigate possible effects of knee joint malalignment, indicated by a high quadriceps (Q) angle (HQ angle >15 degrees ), on the anatomic cross-sectional area (aCSA) of the entire quadriceps and its individual parts, in a group of 17 young asymptomatic men compared with a group of 19 asymptomatic individuals with low Q angle (LQ angle <15 degrees ). The aCSA of the entire quadriceps (TQ), VM, VL, vastus intermedius (VI), rectus femoris (RF), and patellar tendon (PT) were measured during static and dynamic magnetic resonance imaging (MRI) with the quadriceps relaxed and under contraction, respectively. A statistically significant lower aCSA was obtained in the HQ angle group, compared with the LQ angle group, for the TQ, VL, and VI in both static (TQ = 9.9%, VL = 12.9%, and VI = 9.1%; P < 0.05) and dynamic imaging (TQ = 10.7%, P < 0.001; VL = 13.4%, P < 0.01; and VI = 9.8%, P < 0.05) and the aCSA of the VM in dynamic MRI (11.9%; P < 0.01). The muscle atrophy obtained in the HQ angle group may be the result of a protective mechanism that inhibits and progressively adapts muscle behavior to reduce abnormal loading and wear of joint structures.

Inhibition of mTOR in combination with doxorubicin in an experimental model of hepatocellular carcinoma.

BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) is resistant to chemotherapy. We reported that sirolimus, an mTOR inhibitor, has antiangiogenic properties in HCC. Since antiangiogenic therapy may enhance chemotherapy effects, we tested the antitumorigenic properties of sirolimus combined with doxorubicin in experimental HCC. METHODS: Morris Hepatoma (MH) cells were implanted into livers of syngeneic rats. Animals were assigned to sirolimus, pegylated liposomal doxorubicin, both combined or control groups. Tumoral growth was followed by MRI. Antiangiogenic effects were assessed by CD31 immunostaining and capillary tube formation assays. Cell proliferation was monitored in vitro by thymidine incorporation. Expression of p21 and phosphorylated MAPKAP kinase-2 was quantified by immunoblotting. RESULTS: Animals treated with the combination developed smaller tumors with decreased tumor microvessel density compared to animals that received monotherapies. In vitro, inhibition of mTOR further impaired capillary formation in the presence of doxorubicin. Doxorubicin reduced endothelial cell proliferation; inhibition of mTOR accentuated this effect. Doxorubicin stimulated p21 expression and the phosphorylation of MAPKAP kinase-2 in endothelial cells. Addition of mTOR inhibitor down-regulated p21, but did not decrease MAPKAP kinase-2 phosphorylation. CONCLUSIONS: Sirolimus has additive antitumoral and antiangiogenic effects when administered with doxorubicin. These findings offer a rationale for combining mTOR inhibitors with chemotherapy in HCC treatment.

Pelvic radiography in ATLS algorithms: A diminishing role?

BACKGROUND: Pelvic x-ray is a routine part of the primary survey of polytraumatized patients according to Advanced Trauma Life Support (ATLS) guidelines. However, pelvic CT is the gold standard imaging technique in the diagnosis of pelvic fractures. This study was conducted to confirm the safety of a modified ATLS algorithm omitting pelvic x-ray in hemodynamically stable polytraumatized patients with clinically stable pelvis in favour of later pelvic examination by CT scan. METHODS: We conducted a retrospective analysis of all polytraumatized patients in our emergency room between 01.07.2004 and 31.01.2006. Inclusion criteria were blunt abdominal trauma, initial hemodynamic stability and a stable pelvis on clinical examination. We excluded patients requiring immediate intervention because of hemodynamic instability. RESULTS: We reviewed the records of n = 452 polytraumatized patients, of which n = 91 fulfilled inclusion criteria (56% male, mean age = 45 years). The mechanism of trauma included 43% road traffic accidents, 47% falls. In 68/91 (75%) patients, both a pelvic x-ray and a CT examination were performed; the remainder had only pelvic CT. In 6/68 (9%) patients, pelvic fracture was diagnosed by pelvic x-ray. None of these 6 patients was found having a false positive pelvic x-ray, i.e. there was no fracture on pelvic CT scan. In 3/68 (4%) cases a fracture was missed in the pelvic x-ray, but confirmed on CT (false negative on x-ray). None of the diagnosed fractures needed an immediate therapeutic intervention. 5 (56%) were classified type A fractures, and another 4 (44%) B 2.1 in computed tomography (AO classification). One A 2.1 fracture was found in a clinically stable patient who only received CT scan (1/23). CONCLUSION: While pelvic x-ray is an integral part of ATLS assessment, this retrospective study suggests that in hemodynamically stable patients with clinically stable pevis, its sensitivity is only 67% and it may safely be omitted in favor of a pelvic CT examination if such is planned in adjunct assessment and available. The results support the safety and utility of our modified ATLS algorithm. A randomized controlled trial using the algorithm can safely be conducted to confirm the results.

Abdominal magnetic resonance imaging in small rodents using a clinical 1.5 T MR scanner.

Because of superior soft-tissue contrast compared to other imaging techniques, non-invasive abdominal magnetic resonance imaging (MRI) is ideal for monitoring organ regeneration, tissue repair, cancer stage, and treatment effects in a wide variety of experimental animal models. Currently, sophisticated MR protocols, including technically demanding procedures for motion artefact compensation, achieve an MRI resolution limit of < 100 microm under ideal conditions. However, such a high spatial resolution is not required for most experimental rodent studies. This article describes both a detailed imaging protocol for MR data acquisition in a ubiquitously and commercially available 1.5 T MR unit and 3-dimensional volumetry of organs, tissue components, or tumors. Future developments in MR technology will allow in vivo investigation of physiological and pathological processes at the cellular and even the molecular levels. Experimental MRI is crucial for non-invasive monitoring of a broad range of biological processes and will further our general understanding of physiology and disease.

Vascular remodeling and antitumoral effects of mTOR inhibition in a rat model of hepatocellular carcinoma.

BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) is amenable to only few treatments. Inhibitors of the kinase mTOR are a new class of immunosuppressors already in use after liver transplantation. Their antiproliferative and antiangiogenic properties suggest that these drugs could be considered to treat HCC. We investigated the antitumoral effects of mTOR inhibition in a HCC model. METHODS: Hepatoma cells were implanted into livers of syngeneic rats. Animals were treated with the mTOR inhibitor sirolimus for 4 weeks. Tumor growth was monitored by MR imaging. Antiangiogenic effects were assessed in vivo by microvessel density and corrosion casts and in vitro by cell proliferation, tube formation and aortic ring assays. RESULTS: Treated rats had significantly longer survival and developed smaller tumors, fewer extrahepatic metastases and less ascites than controls. Sirolimus decreased intratumoral microvessel density resulting in extensive necrosis. Endothelial cell proliferation was inhibited at lower drug concentrations than hepatoma cells. Tube formation and vascular sprouting of aortic rings were significantly impaired by mTOR inhibition. Casts revealed that in tumors treated with sirolimus vascular sprouting was absent, whereas intussusception was observed. CONCLUSIONS: mTOR inhibition significantly reduces HCC growth and improves survival primarily via antiangiogenic effects. Inhibitors of mTOR may have a role in HCC treatment.

Stent grafting of acute hepatic artery bleeding following pancreatic head resection.

The purpose of this study was to report the potential of hepatic artery stent grafting in cases of acute hemorrhage of the gastroduodenal artery stump following pancreatic head resection. Five consecutive male patients were treated because of acute, life-threatening massive bleeding. Instead of re-operation, emergency angiography, with the potential of endovascular treatment, was performed. Because of bleeding from the hepatic artery, a stent graft (with the over-the-wire or monorail technique) was implanted to control the hemorrhage by preserving patency of the artery. The outcome was evaluated. In all cases, the hepatic artery stent grafting was successfully performed, and the bleeding was immediately stopped. Clinically, immediately after the procedure, there was an obvious improvement in the general patient condition. There were no immediate procedure-related complications. Completion angiography (n=5) demonstrated control of the hemorrhage and patency of the hepatic artery and the stent graft. Although all patients recovered hemodynamically, three individuals died 2 to 10 days after the procedure. The remaining two patients survived, without the need for re-operation. Transluminal stent graft placement in the hepatic artery is a safe and technically feasible solution to control life-threatening bleeding of the gastroduodenal artery stump.

Inhibition of hepatic tumor cell proliferation in vitro and tumor growth in vivo by taltobulin, a synthetic analogue of the tripeptide hemiasterlin.

AIM: To investigate the inhibitory effects of taltobulin (HTI-286), a synthetic analogue of natural hemiasterlin derived from marine sponges, on hepatic tumor growth in vitro and in vivo. METHODS: The potential anti-proliferative effects of HTI-286 on different hepatic tumor cell lines in vitro and in vivo were examined. RESULTS: HTI-286 significantly inhibited proliferation of all three hepatic tumor cell lines (mean IC50 = 2 nmol/L +/- 1 nmol/L) in vitro. Interestingly, no decrease in viable primary human hepatocytes (PHH) was detected under HTI-286 exposure. Moreover, intravenous administration of HTI-286 significantly inhibited tumor growth in vivo (rat allograft model). CONCLUSION: HTI-286 might be considered a potent promising drug in treatment of liver malignancies. HTI-286 is currently undergoing clinical evaluation in cancer patients.

The role of contrast-enhanced spiral CT imaging versus chest X-rays in surgical therapeutic concepts and thoracic aortic injury: a 29-year Swiss retrospective analysis of aortic surgery.

BACKGROUND: Blunt chest trauma accounts for 90% of chest trauma in the civilian population in Europe and the United States and causes 20% of trauma-related deaths. Missed aortic injuries can rupture and lead to subsequent death of the patient. MATERIALS AND METHODS: This retrospective study compared two different imaging strategies, chest X-rays compared to additional contrast-enhanced spiral CT imaging, in patients suffering from blunt thoracic trauma. The study also questioned whether the additional information obtained from CT scans changed further surgical therapeutic concepts or the decision for immediate surgery. RESULTS: Between 1971 and 2001, 39 patients were detected with thoracic trauma and aortic lesions. Of the 28 patients who underwent initial CT scanning, 12 (31%) had an emergency thoracotomy (sternotomy) performed on them, which the other 16 did not require. In four (10%) of these 16 patients, the aorta was stabilised and a possible leak was covered with endovascular stenting. In another eight (21%) of them, the concomitant injuries were initially treated and, following regular check-ups, an elective repair of the aortic lesion was performed after a number of months. In four (10%) patients with intramural haematomas or minor leakage, no intervention was necessary. Eleven (28%) patients did not have a chest CT scan on admission and the diagnosis of a contained aortic rupture was missed. They were readmitted to the hospital between four months and 29 years after the initial accident with symptomatic posttraumatic pseudo-aneurysm of the thoracic aorta. CONCLUSIONS: We believe that helical CT evaluation of the mediastinum should be performed in all patients who undergo blunt thoracic trauma, irrespective of chest radiographic findings. Missed diagnoses can occur after angiography or ultrasound alone, and false-positive diagnoses can also be made. Following the current literature, we therefore recommend a primary routine chest CT scan in all patients with a history of motor vehicle accident (MVA) at a speed of more than 16 km/h (unrestrained) or 48 km/h (restrained). Furthermore, we recommend a CT scan even if the height fallen was as little as seven metres.

Combined femoral and obturator neuropathy caused by synovial cyst of the hip.

A 57-year-old man with a history of severe degenerative lumbar spine disease presented with painful proximal weakness of the right leg. Clinical examination suggested a femoral and obturator neuropathy with a palpable mass in the right groin. Magnetic resonance (MR) imaging disclosed a large synovial cyst of the underlying hip joint in the extrapelvic part of the iliopsoas and external obturator muscles, with femoral and obturator nerve compression. This case highlights the importance of detailed clinical examination in patients with multiple joint disease, the need for considering space-occupying cysts of degenerated joints as a potential cause of nerve damage in unusual locations, and the value of multiplanar MR imaging for proper diagnosis in such situations. Muscle Nerve, 2005.

Use of a mechanical thrombectomy device to recanalize a subacutely occluded aortohepatic bypass after orthotopic liver transplantation.

PURPOSE: To report the use of a rotational thrombectomy device for recanalization of a thrombosed hepatic artery bypass graft in an orthotopic liver transplant (OLT). CASE REPORT: Six months after a second OLT in a 52-year-old man, an iliac conduit used for an aortohepatic bypass became occluded, interrupting arterial supply to the liver transplant. The 8-F Straub Rotarex system was used to successfully remove clot from the bypass graft, avoiding embolization to the hepatic arteries. The recanalized conduit has remained patent for 1 year with the patient on an anticoagulation regimen. CONCLUSIONS: The Rotarex thrombectomy system may be considered an alternative to other percutaneous interventions for the treatment of occluded bypass conduits supplying a liver transplant.

Estimation of central venous pressure by ultrasound.

INTRODUCTION: Increasing blood volume and cardiac output is one of the most commonly needed intervention in the primary care of traumatized and severely ill patients. Although cardiac filling pressures have severe limitations in assessing the preload, central venous pressure (CVP) is the invasive measure most frequently used in clinical practice for the assessment of volume status and cardiac preload. We combined ultrasound and tissue pressure measurement for non-invasive jugular and brachial venous pressure estimation. MATERIALS AND METHODS: CVP was measured invasively and non-invasively using the new technique in 32 critically ill patients. In six volunteers, increasing PEEP was used for the assessment of changes in non-invasive CVP. RESULTS: Non-invasive CVP increased linearly with increasing PEEP, independent of the investigator. Median (range) coefficient of variation (CV) for five consecutive measurements performed by three investigators in volunteers was 15% (6-31%), 14% (4-31%), and 21% (8-42%). Absolute differences between the average non-invasive CVP between investigators was 1.7 cm H2O (0.4-6.6 cm H2O), and the inter-examiner CVP was high (182%, 40-415%). In patients, invasive CVP was 10 mmHg (5-18 mmHg), and the corresponding non-invasive venous pressures were 8 mmHg (3-14 mmHg, basilic vein, p<0.01) and 6 mmHg (3-13 mmHg, jugular vein, p<0.01). The coefficients of variation were 4% (<1%-64%, invasive CVP), 22% (5%-51%, non-invasive basilic vein pressure), and 17% (7%-34%, non-invasive jugular vein pressure). CONCLUSION: Ultrasound-based, non-invasive measurement of venous pressure provides a relatively easy method rapid estimation of changes in CVP, although absolute values may differ substantially from invasive CVP and between different investigators.

Magnetic resonance imaging provides accurate and precise volume determination of the regenerating mouse liver.

Direct and repetitive noninvasive determination of the time course and the strain-specific hepatic regenerative capacity after partial hepatectomy can extend our knowledge about the basic mechanisms of liver regeneration and repair. The aim of this study was to develop a magnetic resonance (MR)-based volumetric procedure to measure the hepatic volume in the regenerating mouse liver. In Balb-C mice (n = 14), varying amounts of liver tissue were resected and MR imaging was performed 24 hours later in a 1.5 Tesla Magnet Unit. Three dimensional (3D) T1- (volumetric interpolated breath-hold examination [VIBE] sequence) and T2-weighted images were acquired with continuous 1-mm thin slices. Animals with and without intravenous administration of paramagnetic contrast agents were compared. Immediately after MR examination, mice were euthanized and livers were weighted. The liver volume was determined on MR images using Cavalieri's method and linear regression analysis was performed from the data obtained. Correlation coefficients between the liver volume measured by MR and the liver weight were 0.98 (T1) and 0.94 (T2) in the group without paramagnetic contrast injection and 0.70 (T1) and 0.96 (T2) after paramagnetic contrast application. We conclude that MR-based liver volumetry allows precise liver volume measurement during hepatic regeneration after partial hepatectomy in mice and can be a valuable tool with regard to experimental hepatology.