Esophageal replacement in rat using porcine intestinal submucosa as a patch or a tube-shaped graft.

This study compares the efficacy of porcine intestinal submucosa (SIS) patch graft versus SIS-tube graft in esophageal replacement, using a novel esophageal regeneration model. Clinical function, as well as macroscopic and microscopic morphology were evaluated in both SIS-treated groups. We performed semi-circumferential esophageal excision followed by repair of the defect using either a SIS-patch graft (group I) or segmental esophageal excision followed by a SIS-tube interposition graft (group II) in rats. The 28-day survival rate was significantly different between the SIS-treated groups (100% in group I vs. 0% in group II). Unlike the rats in group II, which died within the first postoperative month due to esophageal dysfunction, all surviving animals in group I resumed a normal solid diet within a few days after surgery, without signs of esophageal dysfunction and gained weight. Barium swallow studies showed no evidence of fistula, significant stenosis or diverticula. No hematological or serum biochemistry abnormalities were found. By day 150 the SIS patch was replaced by esophageal-derived tissues. In the rat model, a patch graft technique using SIS appeared to induce esophageal regrowth and provided an initial and long-term satisfactory function, while a tube-shaped graft technique using SIS was unsuccessful.

Water enema computed tomography (WE-CT) in the local staging of low colorectal neoplasms: comparison with transrectal ultrasound.

BACKGROUND: To determine the accuracy of computed tomography performed with a water enema application (WE-CT) in the local staging of low colorectal neoplasms and to compare the results with those of transrectal ultrasonography (TRUS). METHODS: Forty patients with low colorectal tumors were evaluated prospectively by CT with the simultaneous administration of a lukewarm rectal enema (0.5-1.5 L). Thin slices (5 mm) and intravenous application of iodinated contrast media were routinely used. TRUS was performed in 18 patients. Tumor size, location, and staging according to the TNM classification of the UICC were registered. Tumors were classified as < T3 (T1 or T2) or as T3 or T4. For staging peritumoral lymph node metastases on WE-CT, two criteria of positivity were tested: N+ if at least one peritumoral node > or 5 mm in diameter was seen (reading A); N+ if at least one peritumoral node > or = 5 mm or three peritumoral nodes < 5 mm were identified (reading B). RESULTS: For the tumor staging, WE-CT showed a sensitivity of 90%, a specificity of 73%, a positive predictive value (PPV) of 90%, a negative predictive value (NPV) of 73%, and an accuracy of 85%. For TRUS, the results were sensitivity of 73%, specificity of 29%, PPV of 62%, NPV of 40%, and an accuracy of 39%. Concerning nodal staging with WE-CT, results were superior when reading A was used: sensitivity = 84%, specificity = 83%, PPV = 73%, NPV = 91%, and accuracy = 84%. TRUS showed a sensitivity of 29%, specificity of 100%, PPV of 100%, NPV of 67%, and an accuracy of 71%. CONCLUSION: WE-CT is a reliable technique for the local staging of low colorectal tumors that can be superior to TRUS. For diagnosis of peritumoral metastatic lymph nodes on WE-CT, the 5-mm diameter cutoff value is the most appropriate size criterion.

Preservative-free lidocaine 1% anterior chamber irrigation as an adjunct to topical anesthesia.

PURPOSE: To evaluate the effect on the central corneal endothelium of anterior chamber irrigation with preservative-free lidocaine 1% as an adjunct to topical anesthesia during phacoemulsification. SETTING: Department of Ophthalmology, Hospital Capuchos, Lisbon, Portugal. METHODS: This prospective, randomized controlled study comprised 59 eyes. Thirty-one eyes had phacoemulsification (in-the-bag cracking technique) under topical anesthesia with anterior chamber irrigation by preservative-free lidocaine 1%. Twenty-eight eyes having the same procedure but with local-regional anesthesia served as the control group. All eyes had preoperative and postoperative specular microscopy and computer-assisted morphometry. A Student's t-test was used for between-group comparison of the following parameters: patient age, central corneal endothelial cell loss, mean endothelial cell size variation, and phacoemulsification ultrasound time Follow-up was 4 weeks. RESULTS: The between-group differences in mean patient age and ultrasound time were not significant. The differences between groups in the endothelial cell parameters were also not significant. Mean postoperative endothelial cell loss was 3.59% +/- 2.79 (SD) in the topical anesthesia group and 4.37 +/- 2.00% in the control group. Mean variation in cell size was 3.71 +/- 1.57% and 3.79 +/- 1.07%, respectively. CONCLUSION: Intracameral infusion of preservative-free lidocaine 1% had no effect on the corneal endothelial cell loss rate or mean cell size variation in this short-term assessment.