Extended rat-ear flap model: a new rodent model for studying the effects of vessel supercharging on flap viability

A new extended rat-ear flap model, with both an axial and a random component, is described. The flap is based on an axial supply by the posterior auricular artery and the posterior facial vein. The random portion, consisting of the rat dorsum, is capable of being supercharged at two separate sites-in the scapular and pelvic regions. There are several advantages to this composite flap. It is a combined axial and random flap. When used as a free flap, the viability of the axial portion serves as an indicator for anastomotic patency. The random portion allows for the investigation of the effects of pharmaceutical manipulation or surgical intervention, e.g., flap supercharging. The results indicate that the axial supply alone can cover approximately 50 percent of the extended rat-ear flap. Moreover, adding supercharging perforators to the random portion significantly increases the area of flap survival. Of interest, an axial vascular supply, coupled with more distal dorsal perforators (pelvic) than proximal (scapular) perforators, may increase survival for the so-called "watershed" area in the middle of the random portion of the flap. Additionally, this study also investigated the relative importance of arterial supply vs. venous drainage, using the extended rat-ear flap model. The flap was either supercharged with both the perforators of the scapular and pelvic arteries, or both scapular and pelvic veins. The results of the study suggests that augmenting venous drainage provides statistically significant improvement (87 percent vs. 51.6 percent) in increasing flap survival, when compared to augmenting the arterial supply. Arterial supercharging provided no improvement in flap survival, when compared to no supercharging (axial vessels + arterial supercharging, 51.6 percent vs. axial vessels alone, 49.9 percent). The results also suggest that providing adequate venous outflow is more important than providing additional arterial blood, and that impaired venous outflow may contribute to some cases of flap failure. However, it should be kept in mind that the best flap survival occurs with both arterial and and venous supercharging.     

In vitro preprogramming of marrow stromal cells for myocardial regeneration

BACKGROUND: We have previously reported that marrow stromal stem cells (MSCs), when implanted into myocardium, can undergo milieu-dependent differentiation to express phenotypes similar to the cells in the immediate microenvironment. We tested the hypothesis that by in vitro preprogramming of MSCs, we may be able to guide their differentiation to express a therapeutically desirable phenotype that is different from those in their microenvironment. METHODS: MSCs were isolated from isogenic Lewis rats, culture expanded, and labeled with beta-gal using retrovirus carrying the lac-Z gene. A subset of the transfected MSCs was then treated with 5-aza-2'deoxycytidine (5-aza). Three weeks after the left ventricles were cryoinjured, either 5-aza-pretreated (n = 10) or untreated (n = 8) MSCs were injected into the myocardial scar. The hearts were harvested 4 to 8 weeks later and stained immunohistochemically for phenotypic markers. RESULTS: The labeled MSCs within the scars that were 5-aza pretreated appeared to be morphologically distinct from the untreated ones. The treated cells (8/10 rats) appeared more myotube-like, with elongated nuclei, linearly aligned with one another, and stained positive for the cardiomyocyte-specific marker troponin I-C. Untreated MSCs (5/8 rats), in contrast, were poorly differentiated, and some appeared to express other phenotypes seen in the scar tissue. CONCLUSIONS: Our findings indicate that in cellular cardiomyoplasty using MSCs, one may select different strategies to achieve specific therapeutic goals. By milieu-dependent differentiation, unmodified MSCs may augment myocardial angiogenesis and myogenesis, whereas converting scar into myogenic tissue may be facilitated by preprogramming of MSCs before implantation.     

Gamma knife radiosurgery for intracranial mature teratoma--long-term results and review of literature

BACKGROUND: The purpose of this report is to present long-term outcomes of gamma knife radiosurgery for intracranial mature teratoma after debulking surgery. METHODS: Three patients with intracranial mature teratoma had initial target volumes of 5.4, 18.7, and 5.1 cm(3), respectively, and were treated by gamma knife radiosurgery between 1993 and 2004. Marginal doses of 17, 12.5, and 13.5 Gy, respectively, were delivered to the tumors at isodose levels of 50%, 50%, and 62%, respectively. The first patient received radiosurgery after surgical removal and conventional radiotherapy. The second patient received similar management, including surgery and radiotherapy, with tumor recurrence. Two additional operations and subsequent radiosurgery were performed on this patient. Based on the favorable results of the first 2 patients, we performed radiosurgery instead of conventional radiotherapy after subtotal surgical removal in the last patient. By reviewing literatures concerning the therapeutic modalities and the long-term results of our 3 patients, we discuss the role of radiosurgery in treating intracranial mature teratoma. RESULTS: A follow-up period of 121, 89, and 31 months, respectively, demonstrated tumor volume reduction rates of 70%, 89%, and 48%, respectively. No evidence of further tumor progression and no radiosurgery-related complication or morbidity was noted. The school performances of the affected children are all above average. CONCLUSIONS: Gamma knife radiosurgery provides a safe and effective alternative as the adjuvant treatment of intracranial mature teratoma after surgical debulking. Previous conventional radiotherapy does not alter final tumor control. Radiosurgery should be considered when residual tumor growth continues with no related symptoms or evaluations of tumor markers during follow-up.     

Experience in the use of the long Gamma nail for 16 femoral shaft fracture that have occurred following initial Asian Pacific Gamma nail fixation for pertrochanteric fractures

From January 1993 to September 2002, 931 patients suffered from intertrochanteric fracture and subrochanteric fracture received open reduction and internal fixation with APGN in our institute. Among these patients, 16 patients (1.7%) developed a femoral shaft fracture after the initial fixation with APGN. Removal of the APGN, closed reduction and fixation with long Gamma nail (LGN) was performed in all the 16 patients. The patients were followed for 12-60 months (average, 39.8 months). The union time of fracture was 12-24 weeks (average, 18.5 weeks) for femoral shaft fractures and 12-20 weeks (average, 16 weeks) for peritrochanteric fractures. Two early complications were noted, including one superficial (6%) infection and one deep (6%) infection. Two malunions (12.5%) developed with no definite functional impairment. The functional results using the Harris hip score were good to excellent. In conclusion, closed reduction and internal fixation with a LGN is very effective in the management of a femoral shaft fracture, a complication of a previous APGN that had been initially used for stabilisation of a pertrochanteric fracture.     

A comparison of feasibility and safety of percutaneous fluoroscopic guided thoracic pedicle screws between Europeans and Asians: is there any difference?

Purpose

To directly compare the safety of fluoroscopic guided percutaneous thoracic pedicle screw placement between Caucasians and Asians.

Methods

This was a retrospective computerized tomography (CT) evaluation study of 880 fluoroscopic guided percutaneous pedicle screws. 440 screws were inserted in 73 European patients and 440 screws were inserted in 75 Asian patients. Screw perforations were classified into Grade 0: no violation; Grade 1: <2 mm perforation; Grade 2: 2–4 mm perforation; and Grade 3: >4 mm perforation. For anterior perforations, the pedicle perforations were classified into Grade 0: no violation, Grade 1: <4 mm perforation; Grade 2: 4–6 mm perforation; and Grade 3: >6 mm perforation.

Results

The inter-rater reliability was adequate with a kappa value of 0.83. The mean age of the study group was 58.3 ± 15.6 years. The indications for surgery were tumor (70.3 %), infection (18.2 %), trauma (6.8 %), osteoporotic fracture (2.7 %) and degenerative diseases (2.0 %). The overall screw perforation rate was 9.7 %, in Europeans 9.1 % and in Asians 10.2 % (p > 0.05). Grade 1 perforation rate was 8.4 %, Grade 2 was 1.2 % and Grade 3 was 0.1 % with no difference in the grade of perforations between Europeans and Asians (p > 0.05). The perforation rate was the highest in T1 (33.3 %), followed by T6 (14.5 %) and T4 (14.0 %). Majority of perforations occurred medially (43.5 %), followed by laterally (25.9 %), and anteriorly (23.5 %). There was no statistical significant difference (p > 0.05) in the perforation rates between right-sided pedicle screws and left-sided pedicle screws (R: 10.0 %, L: 9.3 %).

Conclusions

There were no statistical significant differences in the overall perforation rates, grades of perforations, direction of perforations for implantation of percutaneous thoracic pedicle screws insertion using fluoroscopic guidance between Europeans and Asians. The safety profile for this technique was comparable to the current reported perforation rates for conventional open pedicle screw technique.

     

Geriatric hemodialysis rehabilitation care

The 2 objectives of this review are to provide background information about functional status in older dialysis patients and to discuss the utility of geriatric dialysis rehabilitation. We performed a literature search using PubMed and MedLine. All relevant texts were reviewed for information on functional status and disability in the renal population and in the general population. Data pertaining to geriatric rehabilitation and geriatric dialysis rehabilitation were also reviewed. We show how disability and functional limitations are more prevalent in populations with advanced stages of chronic kidney disease (CKD) compared with those with only mild stages of CKD. We describe data showing that dedicated geriatric dialysis rehabilitation units, using interdisciplinary care models, result in more than 70% of patients meeting their rehabilitation goals and being successfully discharged home. Nephrologists increasingly will be faced with problems arising from functional decline. We conclude by offering suggestions for future changes that may help to stem the rising tide of dialysis disability.     

Effect of preoperative concurrent chemoradiotherapy in locally advanced low rectal cancer after radical resection surgery

To evaluate the outcome of patients with locally advanced low rectal adenocarcinoma who required preoperative concurrent chemoradiotherapy (CCRT), a total of 22 patients underwent preoperative CCRT and radical resection for locally advanced low rectal adenocarcinoma. Patients received concurrent chemotherapy with high-dose 5-fluorouracil (5-FU) in continuous infusion and leucovorin and preoperative radiation with a mean dose of 50.4 Gy (range, 45-50.4 Gy). Radical resection surgery was performed 6 weeks after treatment. Fifty-five percent of patients achieved tumor downstaging, and 14% patients. showed pathological complete remission. No severe hematological and gastrointestinal toxicity of preoperative CCRT was noted. Sphincter-saving rate was 82%, and there were no deaths related to preoperative CCRT and surgery. Overall, 3-year survival rate was 69%, and a rate of locoregional recurrence was 13.6%. This study shows that many patients with locally advanced rectal cancer can be operated on with sphincter-saving radical resection surgery under good local control after preoperative concurrent chemoradiotherapy, which induces tumor downstaging.     

The aggressiveness of urinary tract urothelial carcinoma increases with the severity of chronic kidney disease

OBJECTIVE

To assess, in a retrospective cohort, urinary tract urothelial carcinoma (UT‐UC) in patients with various stages of chronic kidney disease (CKD) and their clinicopathological features, as patients with end‐stage renal disease (ESRD) have a higher incidence of UT‐UC, but the relationship between early stages of CKD and characteristics of UT‐UC are less well known.

PATIENTS AND METHODS

The study included 267 patients with pathologically confirmed UT‐UC from January 1994 to December 2006; all had a physical examination (blood pressure), and measurements of laboratory data (serum creatinine, serum haemoglobin) and pathological data. The glomerular filtration rate (GFR) was calculated using the Modification of Diet in Renal Disease equation. Patients were divided into three groups by individual GFR (mL/min), i.e. >60 (no/mild CKD), 30–60 (CKD stage 3) and <30 (CKD stage 4/5).

RESULTS

The CKD stages included 81 (30.3%) patients with none/mild CKD, 121 (45.3%) with CKD stage 3 and 65 (24.3%) with CKD stage 4/5. There was a significant and parallel increase in the frequency of UT‐UC as CKD severity increased from none/mild CKD to stage 3 (11% vs 55%), and from CKD stage 3 to 4/5 (55% vs 71%; P < 0.05). Pathologically, the frequency of high‐grade and high T stage UT‐UC in patients with CKD stage 3 (90% and 35%, respectively) and CKD stage 4/5 (91% and 29%, respectively) were significantly greater than in the group with none/mild CKD (P < 0.001). Advanced age and more distant metastasis were independent risk factors for patient survival.

CONCLUSION

The aggressiveness of UT‐UC increased with the severity of CKD, and this might have important clinical consequences.