Kumiko Tanuma

Anatomical bases for paravertebral an esthetic block: fluid communication between the thoracic and lumbar paravertebral regions

Summary An injection of a local anesthetics in the paravertebral region produces an analgesic field on the same side of the body, a paravertebral block. One point in question about this block is whether the local anesthetic spreads from the thoracic to the lumbar level of the paravertebral region. The purpose of this study was to find how the anesthetic fluid traveled to the lumbar paravertebral region, if at all. Twelve cadavers were used in this study. 15 ml of crimson dye was injected into the paravertebral region at the 11th thoracic level. The viscerae were removed so that we could examine the dye spread. While the crimson dye spread in the endothoracic fascia posterior to the parietal pleura, it also spread downward in the fascia mostly along the splanchnic nerves. At the upper surface of the diaphragm the dye spread laterally in the fascia, and entered the abdominal cavity through the medial and lateral arcuate ligaments. In the abdominal cavity, the dye was found to have spread so widely in the transversalis fascia that the subcostal, iliohypogastric, ilioinguinal, genitofemoral, lateral femoral cutaneous and femoral nerves were involved. We concluded that the dye in the thoracic paravertebral region can enter the abdominal cavity through the medial and lateral arcuate ligaments. This study explained possible fluid communication between the thoracic and lumbar paravertebral regions and confirmed our former clinical observations. The result is important for the future clinical application of paravertebral anesthesia.

Clinical and vascular anatomical study of distally based sural flap.

Methods:The distally based sural flap has been useful for reconstruction of the distal third portion of the lower leg. We retrospectively review in this report the clinical outcomes. Moreover, we studied the vascular anatomy surrounding the sural nerve using preserved cadavers. Twenty-eight consecutive cases of distally based sural flap transfer were reviewed retrospectively. All flaps were harvested with the deep fascia and lesser saphenous vein, but the sural nerve was excluded in all cases to prevent paresthesia. The sural nerve can be easily detached from the flap by meticulous dissection from the deep fascia without causing significant bleeding. In the vascular anatomic study, barium was injected through the femoral artery after elevating the flap in 20 legs of preserved cadavers. Subsequently, tissue specimens were harvested from the upper, middle, and lower sites of the flap for histologic analyses. Results:Clinically, 22 of 28 flaps survived completely. Distal partial necrosis was observed in 5 flaps, and total necrosis was observed in 1 flap. Causes of total or partial necrosis have been suggested to be dependent on flap shape, pedicle length, and complicating diseases. Anatomic angiography revealed that small extrinsic vessels around the sural nerve and the lesser saphenous vein are important, especially in distally-based sural flap transfer; those around the sural nerve seem to have the most important impact on flap survival. The sural nerve has fewer intrinsic vessels than the extrinsic vessels of the sural nerve and lesser saphenous vein. Conclusion:The distally based sural flap was useful for reconstruction of the distal third portion of the lower leg. Moreover, these clinical and anatomic findings suggest that the sural nerve can be preserved to prevent surgically induced paresthesia.

Variations of the bilateral testicular veins: embryological and clinical considerations

Variations of the bilateral testicular veins were observed during routine dissection of the posterior abdominal wall in a 77-year-old male Japanese cadaver. The right testicular vein consisted of the lateral and medial testicular veins. The right lateral testicular vein drained into the right renal vein. The right medial testicular vein accompanied the right testicular artery to ascend obliquely and drained into the left aspect of the inferior vena cava. The left testicular vein was composed of the lateral, middle and medial testicular veins. Three left testicular veins accompanied the left testicular artery to course cranially and then finally drained into the left renal vein.

Nerve fiber analysis for the lingual nerve of the human adult subjects

The neuro-motor control of the human tongue musculature had not been investigated in detail. This study identified first that the lingual nerve should play the neuro-motor control of some lingual muscles. Six en bloc samples (12 sides), including the tissues from the skull base to the hyoid bone, and three whole tongues were obtained from adult human cadavers. The former samples were used for the study of nerve fiber analysis of the lingual nerve with the aid of binocular stereomicroscope, and the latter samples were used for histological study by serial section method. On nerve fiber analysis of the lingual nerve from the trigeminal ganglion to the tongue musculature, we found that the motor- root of the trigeminal nerve gave off its supply to the lingual nerve and traveled into the lingual nerve, and branched to the superior and the inferior longitudinal muscles. On histological study, it was revealed that in the anterior part of the tongue the superior and the inferior longitudinal muscles surrounded the other lingual musculature and combined with the sub-mucosal connective tissues closely like the cutaneous muscle, for example, the facial muscles. The lingual nerve entered the inner side of the space between the genioglossus and the inferior longitudinal muscles with the lingual artery. These findings suggested that the superior and the inferior longitudinal muscles should be innervated by the motor fibers traveled into the lingual nerve from the motor root of the trigeminal nerve, and do not originate from the myotome originating in occipital somites but branchial muscles.

Anatomical considerations of endothoracic dwelling catheter

We previously reported a case of catheter placement in the endothoracic fascia. Repreated administration through the catheter resulted in steady unilateral anesthesia. To investigate this anesthetic mechanism, we investigated how the anesthetic agent spread in the fascia of two cadavers. We found that the endothoracic fascia is so loose that dye injected in the cadavers spread both longitudinally and laterally in the paravertebral region. In the case of catheter placement in the endothoracic fascia we previously reported [1,2], a 22-year-old woman was brought to the operating room for an appendectomy. We elected to proceed with epidural anesthesia for this surgical operation. With the patient in the lateral position, a 17-G Tuohy needle was inserted at the Tl1-12 interspace through the paramedian approach. The skin was punctured 3 cm lateral from the median line. We found a loss of resistance-to-saline when the needle was inserted about 8cm. A 20-G open-tip Teflon epidural catheter (Abbott, North Chicago, IL, USA) was threaded through the needle. The catheter tip was 4 cm left in what was originally presumed to be epidural space. No blood or other fluid could be aspirated through the catheter. Twelve ml of 2% mepivacaine was administered through this catheter. The analgesic examination 10 min after the deposition showed left hemiparesis from T4 to L3. A subsequent X-ray and computed tomography (CT) scan were performed which revealed

Clinical reappraisal of the segmental pectoralis major turn-over flap for coverage of the local mediastinal wound.

The viability of a long and narrow pectoralis major turn-over flap based on one intercostal muscle perforator was supported by the result of our cadaveric injection study. This flap preserves the muscular strength and aesthetic contour of the anterior axillary line, and is attractive for reconstruction of the mid-sternum.