Virtual CT colectomy by three-dimensional imaging using multidetector-row CT for laparoscopic colorectal surgery

Laparoscopic colorectal surgery has been attracting attention for its capacity to improve the quality of life (QOL) of patients. However, there are disadvantages to this approach, namely, it is difficult to obtain an image of the entire view of the operative field, and organs and lesions cannot be manipulated directly by the surgeon during surgery. For this reason, it takes a relatively large amount of time to ligate vessel, which can vary between patients. Furthermore, vessels and organs can be damaged during lymph nodes dissection under laparoscopic guidance, leading to heavy bleeding that prevents the surgeon from having access to a good view of the operative field. Then, to assess preoperatively the vascular anatomy, we carried out multiphase, contrast-enhanced examinations using multidetector-row CT (MDCT) on patients with colorectal cancer, and prepared the fused image of 3D images of arteries, veins, the colorectum, organs, and tumor. We called the utilization of 3D imaging virtual CT colectomy, which contributed to rapid and safe manipulation of the origins of the arteries and the veins, as well as lymph nodes dissection, without incurring injury to the involved arteries and veins.

Effect of saline pushing after contrast material injection in abdominal multidetector computed tomography with the use of different iodine concentrations

PURPOSE

To investigate whether saline pushing after contrast material improves hepatic vascular and parenchymal enhancement, and to determine whether this technique permits decreased contrast material concentration.

MATERIAL AND METHODS

120 patients who underwent hepatic multidetector computed tomography were divided randomly into four groups (Groups A-D): receiving 100 ml of contrast material (300 mgI/ml) only (A) or with 50 ml of saline solution (B); or 100 ml of contrast material (350 mgI/ml) only (C) or with 50 ml of saline solution (D). Computed tomography (CT) values of the aorta in the arterial phase, the portal vein in the portal venous inflow phase, and the liver in the hepatic phase were measured. Visualization of the hepatic artery and the portal vein by 3D CT angiography was evaluated as well.

RESULTS

Although the enhancement values of the aorta were not improved significantly with saline pushing, they continued at a high level to the latter slices with saline pushing. The enhancement value of the portal vein increased significantly and CT portography was improved with saline pushing. The enhancement value of the liver was not improved significantly using saline pushing. In a comparison between groups B and C, the enhancement values of the aorta and portal vein and the visualization of CT arteriography and portography were not statistically different.

CONCLUSION

The saline pushing technique can contribute to a decrease in contrast material concentration for 3D CT arteriography and portography.

[Three-dimensional CT angiography of the hepatic artery with multislice CT: differences in image quality according to scanning pitch]

Three-dimensional CT angiography was reconstructed from the hepatic artery using multislice CT, and the effect of pitch during scanning on the quality of obtained images was examined. We randomly divided patients into two groups, with images of one group scanned at helical pitch 3 and images of the other at helical pitch 5.5. CT angiography was reconstructed by a volume-rendering technique. Evaluation was done visually, taking the sharpness of images of branches of the hepatic artery as a measure. Three-dimensional imaging scanned at pitch 3 tended to be better than that scanned at pitch 5.5.

Assessment of extensive surgery for locally advanced lung cancer. Safety and efficacy of induction therapy

OBJECTIVE

Locally advanced lung cancer has a poor prognosis, despite extensive surgery conducted in an effort to improve survival. We evaluated the safety and efficacy of induction therapy prior to extensive surgery for locally advanced lung cancer.

METHODS

Primary resection for lung cancer was done in 549 consecutive patients divided into three groups; 446 undergoing standard pulmonary resection (no extensive surgery), 87 undergoing extensive surgery without induction therapy, and 16 undergoing surgery after induction therapy.

RESULTS

Morbidity was 23.5%, 28.6%, and 43.8%, respectively. The rate was significantly higher in the induction group compared with the no extensive surgery group (P < 0.05). Surgical mortality was 0.67%, 3.4%, and 6.3%, respectively. The difference was statistically significant between the no extensive surgery and extensive surgery groups (P < 0.02), and between the no extensive surgery and induction groups (P < 0.02). Hospital mortality was 2.2%, 9.2%, and 6.3%, respectively. The rates were significantly higher in the extensive surgery (P < 0.01) and induction (P < 0.05) groups compared to the no extensive surgery group. Five-year survival was 50.3% for the patients who received induction therapy, and 14.7% for the patients who did not receive induction therapy.

CONCLUSIONS

Survival differences between the induction and non induction groups were not significant, but some patients with T3 or T4 disease may benefit from induction therapy. The high morbidity of induction treatment should be recognized, and strict candidate selection and careful postoperative care used to help prevent increased mortality.

[Intrapulmonary laceration revealed by computed tomography in a patient with pneumomediastinum]

An 18-year-old man had bronchial asthma and a pneumomediastinum. A computed tomographic scan of the chest revealed the pneumomediastinum, intrapulmonary laceration of the S1b, and a small amount of air in the perivascular space from V1a to V1. Increased pressure in intrapulmonary airways may have resulted in ruptured S1b alveoli and air leakage into the interstitium between the surrounding secondary lobules. The air may have moved along the perivascular space (pulmonary vein) toward the hilum, and eventually into the mediastinum. We know of no previous report of pneumomediastinum in which images of intrapulmonary lesions are presented. In this case computed tomography revealed the mechanism by which the pneumomediastinum probably developed.

[Clinical considerations from sixteen cases with mediastinal malignant lymphoma]

Sixteen cases with mediastinal malignant lymphoma were treated in our department and a correlation made between the prognosis and other factors: first symptom, maximum diameter of the tumor, type of operation, pathological subtype, clinical stage. First symptom and compressed or invasive symptom with mediastinal mass were not related to prognosis. The cases with bulky tumor over 10 cm in diameter showed a tendency toward poorer prognosis. Complete or incomplete resection did not have significant effect. The cases of Hodgkin's disease had relatively good prognosis. Classification of clinical stage (Ann Arbor classification) did not show significant correlation with prognosis and may be inadequate for staging of mediastinal malignant lymphoma. Surgical treatment may be adapted for mediastinal Hodgkin's disease and early stages of thymic malignant lymphoma.

[A case of hamartoma originated from the chest wall]

Hamartoma originated from the chest wall is rare. All reported cases are infant's ones. A 16-year-old man was admitted to our hospital because of chest pain and abnormal shadow in routine chest X-ray film. Thoracotomy was performed under the diagnosis of pulmonary sequestration in the left apical region. However, the operation revealed a tumor originated from the chest wall, which was diagnosed hamartoma by histological examination. Re-operation was required because of hemothorax caused by residual tumor. Second and third ribs were resected with residual tumor. There is no evidence of recurrence one year after the second operation.

[A high concentration of itraconazole in an aspergilloma]

A 66-year-old woman was given 100 mg/day of itraconazole for eight months to treat pulmonary aspergillosis with an aspergilloma. The amount of purulent sputum decreased, but open drainage was done because the fever continued and because no improvement was seen on the chest X-ray film. No aspergillus was cultured from the surgical specimen, but fungi were observed microscopically. The concentration of itraconazole in plasma was 249 ng/ml. The concentrations in specimens of the lung and of the aspergilloma obtained by thoracotomy were 81 ng/g and 837 ng/g, respectively. The high concentration in the aspergilloma had made the fungus inactive. The itraconazole concentration may have been very high for three reasons: (1) the concentration increased in purulent fluid, (2) itraconazole easily entered the aspergilloma through the root at the cavity wall, and (3) itraconazole dissolved in lipid derived from destroyed fungus.

Combined dose ratios of dopamine and dobutamine and right ventricular performance after cardiac surgery

The effect of combined administration of different dose ratios of dobutamine (DB) and dopamine (DA) (DB/DA ratio of 1:1; 1.5:0.5; 2:0; 0.5:1.5; and 0:2), with the added dose kept constant (10 micrograms/kg/min-20 micrograms/kg/min), on right ventricular function (measured by the thermal washout method with the aid of a rapid-response thermistor) was determined in ten patients after cardiac surgery (between 12 and 24 h after surgery). The following values represent the mean +/- SD of DB only and of the DB/DA-equal combination vs DA only. The DB/DA-equal or DB-dominant combination increased the right ventricular ejection fraction vs DA only (0.39 +/- 0.12 [p less than 0.01] and 0.37 +/- 0.11 [p less than 0.05], respectively, vs 0.32 +/- 0.12) and the stroke volume index (43 +/- 12 ml/m2 [p less than 0.01] and 41 +/- 15 ml/m2, respectively, vs 38 +/- 14 ml/m2) and decreased right ventricular end-diastolic pressure (RVEDP) (10 +/- 4 mm Hg [p less than 0.01] and 11 +/- 4 mm Hg [p less than 0.05], respectively, vs 13 +/- 5 mm Hg) and pulmonary capillary wedge pressure (10 +/- 4 mm Hg [p less than 0.01] and 12 +/- 5 mm Hg [p less than 0.05], respectively, vs 14 +/- 6 mm Hg) to the same degree as DB alone. The DB/DA-equal or DB-dominant combination did not induce tachycardia (heart rate, 105 +/- 11 [p less than 0.05] and 95 +/- 14 beats per minute, respectively, vs 90 +/- 17 beats per minute) or have any effect on the right ventricular end-diastolic volume index (RVEDVI) (115 +/- 30 ml/m2 and 117 +/- 33 ml/m2, respectively, vs 127 +/- 42 ml/m2). Moreover, the diastolic parameters of the right ventricle (the ratio of RVEDVI/RVEDP: 15 +/- 8 [p less than 0.05] and 13 +/- 7, ml/mm Hg/m2, respectively, 11 +/- 5 ml/mm Hg/m2) decreased as the ratio of DA increased. This change in the diastolic properties of the right ventricle might have been caused by release of norepinephrine in the myocardium by DA or by improved coronary perfusion with DB. The DB/DA-equal and DB-dominant combinations were superior to DB or DA alone and to the DA-dominant combination in obtaining enhanced right ventricular performance.

Effects of injection site on the accuracy of thermal washout right ventricular ejection fraction measurements in clinical and model investigations

The purpose of this investigation was to improve the accuracy of measurement of thermal right ventricular ejection fraction (RVEF) using the modified Swan-Ganz catheter. Three serial ejection fractions (EFs) (EF1, 2, 3) and the mean were calculated, based on Holt's theory. RVEFs were compared between right ventricular (RV) and atrial (RA) injection in ten intensive care unit (ICU) patients using a modified catheter having RV and RA orifices (15 cm and 30 cm from the distal end, respectively), and paired duplicate (two patients) or triplicate (eight patients) measurements were performed. To determine what factors interfere with RVEF, a model heart (with diastolic volume of 150 ml) was constructed, in which model injection of cold water to the direct inflow tract (RA), to the direct mixing chamber (RV), or through the catheter running in the inflow tract were compared. When EFs were compared between RV and RA injection, those for the former were greater (RV vs RA in EF1 and EFmean: 0.46 +/- 0.15 vs 0.23 +/- 0.11 in EF1, and 0.45 +/- 0.13 vs 0.28 +/- 0.11 in EFmean, mean +/- SD, p less than 0.01). When the serial EFs were compared in each injection type, in the RV injection EF3 was the smallest as was EF1 in the RA injection. The same phenomenon was observed in the model as in the patients, and moreover when cold water was injected in RA through a catheter running through the circuit, EFs were greatly underestimated (EF1 = 0.29 +/- 0.02 at preset EF = 0.4). We conclude that these phenomena were caused by sluggish movement of the cold indicator from RA to RV when injected into RA, and by interference with the cooled cardiac chamber and catheter. Consequently, the first or second EFs obtained from RV injection might be closest to the actual values because of the least interference with those factors.

[Analysis of factors influencing the accuracy of ejection fraction measurement based on the thermal washout technic--investigation in a model heart]

Evaluation of ejection fraction and ventricular volume is more difficult in the right side of the heart than in the left side. Thermal washout method in the right ventricle with the aid of a rapid response thermistor made it possible in the clinical practice, but its accuracy is uncertain. We attempted to elucidate what factors could influence the accuracy of the measurement of the right ventricular ejection fractions in a model circuit and artificial heart equipped with two one-way valves. Findings are as follow: 1) By ventricular injection of the cold water it is possible to evaluate the ejection fractions more accurately than by atrial injection. The latter technique measured the ejection fraction 8.4% lower than the actual values. 2) The first ejection fraction measured will be the most accurate among the serially obtained ejection fractions using a thermal washout curve. 3) When the ejection fraction is high, the ejection fractions calculated from the later part of a thermal washout curve will be falsely low. 4) When the cold water is injected through the catheter running in the circuit, the effect of the catheter cooling could not be neglected and ejection fraction will be measured falsely low. The temperature change is so small in the later part of the descending limb of the thermal washout curve, that the effect of catheter cooling and ventricular cooling will be exaggerated and the calculation of the temperature change will be measured falsely high. This seems to be the cause of our findings in this research.(ABSTRACT TRUNCATED AT 250 WORDS)