Biomedical subjects

Y D Gu

Publications and source records attributed to Y D Gu.

At least 37 records · Page 2Linked to original sources

PubMed1996

Use of the phrenic nerve for brachial plexus reconstruction.

To examine the clinical effectiveness and safety of phrenic nerve neurotization for brachial plexus reconstruction, the authors retrospectively analyzed the surgically treated cases within the period between August 1970 and March 1990. There was a total of 180 patients who sustained brachial plexus injuries and had phrenic nerve transfer. The phrenic nerve was identified and traced distally to give the longest possible length and sectioned. The proximal stump was coapted to the distal segment of the musculocutaneous nerve, either directly or through a nerve graft. Sixty-five patients who were seen in followup for >2 years were studied. The time taken for the return of a muscle power rating of 3 (M3) in the biceps muscle ranged from 3 to 30 months; the average time was 9.5 months. Of the patients, 84.6% regained biceps power to M3 and greater strength. Only 1 patient had a transient respiratory problem after surgery. Pulmonary function tests showed decreased pulmonary capacities within 1 year of operation, improving toward 2 years. Thus, it is concluded that phrenic nerve neurotization can be accepted as a sound option for the restoration of biceps function in brachial plexus injury.

Adolescent↗

PubMed1996

Introduction of a modified Krukenberg operation.

A modified Krukenberg operation was used in 25 patients to reconstruct their limb function. We modified the operation as follows: (1) only pronator teres and supinator are preserved as motor muscles, (2) the flexor carpi ulnaris is included in the ulnar ray flap and the brachioradialis in the radial ray flap, and (3) the length of the forearm trunk is kept 12 to 15 cm. Having undergone strict postoperative training, 22 of 25 patients got excellent or good results.

Adolescent↗

PubMed1994

An experimental study of contralateral C7 root transfer with vascularized nerve grafting to treat brachial plexus root avulsion.

Experimental rat models of simulated brachial plexus injuries were devised to compare the effect of contralateral C7 root transfer with phrenic neurotization. The effect of vascularized nerve grafting (VNG) was also compared with the use of conventional nerve grafts (CNG) in the treatment of root avulsion of the brachial plexus. 160 rats were randomly divided into four groups of 40 each; contralateral C7 root transfer with a vascularized ulnar nerve graft (C7-VNG), contralateral C7 root transfer with conventional ulnar nerve grafting (C7-CNG), ipsilateral phrenic nerve transfer with a vascularized ulnar nerve graft (P-VNG) and ipsilateral phrenic nerve transfer with conventional ulnar nerve grafting (P-CNG). Electrophysiological and histological examinations and functional evaluation were performed at different post-operative intervals. C7 root transfer was found to be superior to phrenic nerve transfer and VNG superior to CNG. Severance of the C7 nerve root was not found to affect limb function on the healthy side.

Animals↗

PubMed1994

Distribution of the sensory endings of the C7 nerve root and its clinic significance.

50 patients with root avulsion of the brachial plexus have been treated with contralateral C7 root neurotization. Abnormal cutaneous sensation was found on the index finger in 37 cases (74%), on the middle finger in 29 cases (58%), on the thumb in 19 cases (38%), on the ring finger in ten cases (20%), and on the little finger in one case (2%). Seven patients had no abnormal cutaneous sensation. It is suggested that the area of skin innervated by C7 is centred on the index finger, together with the thumb and middle fingers.

Adolescent↗

PubMed1994

Electrophysiological changes after severance of the C7 nerve root.

Since 1986, contralateral C7 root transfer has been used to treat brachial plexus root avulsions in our hospital. We performed post-operative electrophysiological examinations of the healthy-side limb in the first 27 patients. Electromyography and nerve conduction studies on the healthy side demonstrated mild abnormalities only of individual limb muscles in a few cases. These changes mostly recovered during the follow-up period. In the measurement of radial nerve motor conduction, median nerve sensory conduction and somato-sensory evoked potentials, we found that the amplitude of the median nerve sensory conduction alone was slightly lower than that of the control group (p < 0.05). The results showed that severance of C7 caused no permanent functional damage to the upper limb.

Adolescent↗

PubMed1994

[Distal blood pressure changes after ligation of the femoral artery or vein in the rat].

In the rat, immediately after ligation of the femoral artery below the profundus branch, the intraluminal pressure at the distal part dropped from 15.80kPa to 4.82kPa, and continued to decrease even after seven days. For the femoral vein, the distal intraluminal pressure rose from 0.67kPa to 3.91kPa in one minute. After one hour it dropped slowly and reached 1.25kPa after 24 hours. After seven days it was 0.74kPa. The author consider that it is unsuitable for the distal cut end of an artery or a vein to be used as the feeding vessel in microvascular free tissue transfer, because lowered blood pressure might result in inadequate tissue perfusion. When a big artery of limb was injured, it should be repaired no matter whether the collateral branch can maintain the distal circulation of the limb or not.

Animals↗

PubMed1994

[Microsurgical treatment of bone and joint defects of hand].

From 1972 to 1990 seven kinds of microsurgical operations were used for treatment of bone and joint defects of hand. Among these cases 23 survived and 1 failed. The patients were followed up for 2-20 years. The functional results were good in 77.4%. The improved surgical procedures: (1) Use dorsalis pedis artery as the single pedicle to provide double vascular supply for double joint graft from one toe. (2) Change the fixing position of metatarsal to increase the degree of motion of the joint. The operative indications and the factors related to the survival and function are discussed.

Adolescent↗

PubMed1994

[Cigarette smoking and circulatory crisis in tissue transfer].

Circulatory crisis occurred in 2 cases of toe-to-hand transfer and 1 case of musculocutaneous free flap after smoking. Two of them failed and 1 survived after exceeding anti-spasm and anti-thrombosis treatment. Experimental studies showed harmful influences of cigarette smoking on endothelial healing process at the vascular anastomosis site, which was covered by endothelial cells in 16%-32% and platelet in 8%-10% of the smoking group 5-10 days after operation, but in 75%-100% and 0% of the normal group. The mechanism and characteristics of circulatory crisis caused by cigarette smoking are discussed.

Adult↗

PubMed1994

Entrapment of posterior interosseous nerve of forearm. Report of 25 cases.

Of the 25 cases of entrapment, or compression syndrome of the posterior interosseous nerve of the forearm reported, 23 were treated surgically. The compressing or entrapping factors found during the operations consisted of 14 sites in tendinous tissues, 12 in vessels, 6 in scar adhesions, and 3 unclear. Of 11 cases each had 2 or more compression sites. 19 patients underwent local decompression. And 4 cases had membranous and degenerated nerves resection and end-to-end anastomoses. Hypertrophy and inflammation appeared to be the main pathological changes in 10 cases. The causes and pathology are discussed and the early diagnosis and treatment emphasized.

Adolescent↗

PubMed1993

Clinical and experimental studies of cigarette smoking in microvascular tissue transfers.

Circulatory crisis, attributed to cigarette smoking, in three microvascular cases (two toe transfers, one musculocutaneous flap) is reported. After anticoagulation and antispasm treatment only one transfer survived. Coordinated experimental studies in the rat demonstrated that cigarette smoking delayed anastomotic healing. Five days after anastomoses were performed, endothelial cells completely covered the sutures in the experimental smoking group in only 16-19% of sutures, while the control group had a 75% coverage rate. Mechanisms and characteristics of circulatory crisis caused by cigarette smoking are discussed.

Adult↗

PubMed1993

Toe-to-hand transfer: an analysis of 14 failed cases.

Fourteen failed cases of 325 patients who had undergone the operation of toe-to-hand transfer to reconstruct the thumb and/or the finger are reported. Five key factors were related to the survival of the transferred toe: two sets of arterial blood supply in the case of an arterial anomaly, the resection of diseased vascular segments, the observation of capillary blood refill for the judgment of circulatory crisis, and the prevention and treatment of a hypercoagulable state.

Adult↗

PubMed1993

The significance of venous drainage in free flap transfer.

A skin flap in the anterior abdominal wall of the S-D rat was designed so that it was supplied by the superficial epigastric branch of the femoral artery on the right side. Venous drainage was effected through one of five designs: (1) the superficial epigastric vein on the same side, (2) the lateral abdominal vein on the same side, (3) the lateral abdominal vein on the opposite side, (4) the superficial epigastric vein on the opposite side, or (5) a combination of the latter three. Seventy-seven rats were available for final analysis. The surviving percentage area of the flap was found to improve with increased venous drainage and when the arterial blood had to traverse the flap to reach the diagonally situated draining vein. The use of venae commitante as the draining vein is not satisfactory.

Abdominal Muscles↗

PubMed1993

Circulatory crisis caused by cigarette smoking in tissue transfer. Clinical and experimental studies.

Cigarette smoking-induced circulatory crisis occurred in two patients receiving toe transfer and one patient having musculocutaneous flap. After anticoagulation and antispasm treatment, one survived and two failed. Experimental studies demonstrated that cigarette smoking is harmful to the healing of endothelia at the anastomotic site of vessels. Five days after operation, the complete recovery rate of the endothelium over sutures of anastomotic sites was 16%-19% in smoking groups, but 75% in the control group. The mechanism and characteristics of circulatory crisis caused by cigarette smoking are discussed.

Adult↗

PubMed1993

Free toe transfer for thumb and finger reconstruction in 300 cases.

From 1966 to 1989, we performed free toe transfer for thumb and finger reconstruction in 300 patients, with 286 survivals and 14 failures, a total survival rate of 95.55 percent. Follow-up for 2 to 23 years showed that movement and sensation of the reconstructed thumbs and fingers were satisfactory in all of the 286 cases. The optimal indications for the operation were defect of the thumb at the plane of the metacarpophalangeal joint and defects of the second to fifth fingers. Besides atraumatic isolation of the second toe and sophisticated microsurgical suturing technique, special attention was paid to intraoperative vascular variations, to providing the double arterial blood supply system if necessary, and to the identification and management of postoperative circulatory crisis.

Adult↗

PubMed1992

Experimental study of free toe replantation in rats.

A rat model for free second toe replantation, free hallux-to-thumb transplantation, and combined free hallux-to-thumb transplantation and free second-toe-to-index transfer is described. Experimental devices, operative methods, and the keys to success are discussed.

Animals↗

PubMed1992

A comparison of arterial and venous flaps.

The survival rate and elastic properties of the anterior abdominal skin flap in Sprague-Dawley rats were studied in three groups of animals. In group 1 where the flaps were supplied by a normal artery, arterial flaps (1A) had better survival rate and elastic properties than venous flaps (1B). In group 2, where the flaps were supplied by an artery with diminished perfusion pressure, the arterial flaps (2A) still had slightly better results than venous flaps (2B). However, in group 3 where the flaps were supplied by a vein, venous flaps (3B) had better results than arterial flaps (3A).

Abdomen↗

PubMed1992

Seventh cervical nerve root transfer from the contralateral healthy side for treatment of brachial plexus root avulsion.

Cervical root nerve transfer from the contralateral side has been used for the treatment of brachial plexus root avulsion in 49 patients. Resection of C7 root from the healthy side has produced no long-term symptoms or signs. Nine patients with ten recipient nerves have been followed up for more than two years and seven have obtained a functional recovery. This operation offers a new approach for the treatment of brachial plexus root avulsion.

Adolescent↗

PubMed1992

Vessel pathology and its clinical significance in toe transfer.

One hundred cases of toe transfer were subjected to histopathologic vessel examination. Results indicated that vascular injuries are crucially responsible for perioperative and postoperative crisis. A thorough resection of the abnormal vessel segment can prevent circulatory crisis and elevate the survival rate.

Blood Vessels↗