Comparison of pancreaticoduodenal transplants (PDT) and duct-ligated pancreas transplant (DLPT) were performed using syngeneic and allogeneic studies in rats. Both DLPT and PDT allogeneic grafts showed mild rejection. DLPT groups showed disorganized pathology and acini replaced by fat. Eventually, massive fibrosis was seen in the Islets of Langerhans, as well as rejection cellular infiltrates. In both PDT groups, normal histology was observed in the same period. Thus the effect of duct occlusion is highly detrimental for the grafts.

This study was conducted by consecutively transplanting spleens, which had gonads implanted previously. A total of 84 cases for infantile testicles and 106 cases for ovarian follicles were performed. In the case of ovarian implants, the results were determined by the total number of follicle implants. A modified spleen transplantation technique called double implantation of ovarian follicles was applied to increase the amount of the implants. In this technique, an extra spleen is implanted into the potential donor so that the ovarian follicles can be implanted to two different spleens, doubling the amount of implants. Through consecutive spleen transplantation, we observed the results beyond a typical rat's life span. In many of these cases, we found more aggressive forms of malignant tumor, seminoma and dysgerminoma. We present the results and discuss possible pathogenic mechanisms of tumor formation.

We examined the results after implantation of ovarian follicles by various modes in a total of 82 cases. One or five ovarian follicles were implanted into spleens in castrated female rats. In 20 cases among these, each five follicles were implanted into native and transplanted spleens after spleen transplantation (double implantation of the ovary). Through consecutive spleen transplantation, we observed the results beyond the rat's life span for a limited period. In many cases, we found a more aggressive form of malignant tumor, i.e., dysgerminoma. We present the results and discuss the modes of implantations and possible pathogenetic mechanisms of tumor formation. © 2003 Wiley‐Liss, Inc. MICROSURGERY 23:450–453 2003

Two needles were designed in order to revascularize an ischemic myocardium in the event of left coronary artery occlusion. This study was conducted by performing the Lee modified Fox‐Montorsi heart‐lung transplant on 25 San Diego Microsurgical Institute‐bred Sprague Dawley rats that were subjected to left coronary artery ligation in each case. Of these 25 rats, a straight‐porous (SP) needling procedure was applied to 9 heterotopically transplanted rat hearts, and a distinct horseshoe (HS)‐shaped needle application was performed on the remaining 16 heterotopically transplanted rat hearts. This report represents an acute study on the efficiency of these two needles to transmit oxygen‐rich blood from the left ventricle into the ischemic myocardium. Doppler readings for male vs. female transplants showed that the control peak (PK) and mean (MN) kHz values are on the average of 0.20 kHz higher in males than in females. However, control heart rate values in both sexes are approximately equal. Ligation of the left coronary artery caused a dramatic decrease of PK and MN kHz values in both sexes, while heart rate showed no significant decrease from the original control values in response to ischemia. Application of the SP needle showed only a slight return of PK and MN values in both sexes, but heart rate values increased to levels higher than the original control values. The HS needling procedure was able to recover approximately 80% of the control PK and MN kHz values in both sexes. Thus, these data indicate that the HS needle can successfully transmit left ventricular blood into the myocardium. © 2003 Wiley‐Liss, Inc. MICROSURGERY 23:443–449 2003

It is well‐known that 30% of the remaining liver mass, following partial hepatectomy, regenerates to full original mass within 2 weeks in rats. In order to carry the transplanted rat liver to repeated transplantation, a technique of combining 30% of the liver with the pancreaticoduodenum and spleen transplantation is performed in this consecutive organ transplantation study. Our laboratory observed several 37‐month‐old transplanted rats by carrying through 2–3 generations, and histological disclosure were made. Because the partial liver transplants did not regenerate after the transplantation with other splanchnic organs, this technique is not so difficult though subsequent surgical maneuvers are needed and the liver histology proved entirely normal in every aspect when followed beyond the rat's life span of 24 months. © 2003 Wiley‐Liss, Inc. MICROSURGERY 23:440–442 2003

Seventy-seven Lewis adult rats received autologous testicular implants in the spleen. These spleens were retransplanted in a consecutive transplant fashion as we described earlier. Some were observed as long as 26 to 27 months. Although earlier splenic-testicular transplants showed benign granulosa cell tumors, some of the long-term follow-ups showed a seminoma-like transformation.

This report details mouse-to-rat testicular transplantation with immediate revascularization. Donor preparation involved grafting a long segment of aorta and inferior vena cava (IVC) containing the testicular artery and vein. The graft aorta and IVC were anastomosed to the rat aorta and IVC, respectively. Vasovasostomy was completed and the scrotal epithelia were anastomosed to draw the graft toward the host scrotal sac. Twenty-nine of 53 transplants were determined to be viable. Histologically, 6- to 18-hr-old grafts displayed moderate to minimal polymorphonuclear neutrophil (PMN) infiltrates. Ischemia set in somewhere between 18-24 hr postoperatively. Beyond 24 hr the grafts displayed progressive infiltration of PMN and perivascular and intertubular lymphocytes, disorganization of the germinal epithelium, and cessation of spermatogenesis.

Previous studies have suggested that hepatic arterial flow in heterotopic partial liver transplants is necessary to ensure graft survival and regenerative capacity. This report presents findings in a syngeneic rat strain (Lewis) that partial liver transplants can be successfully heterotopically transplanted in the long term with the only inflow coming from the portal vein. When the host liver undergoes a nearly complete resection at 3–4 weeks, the transplanted liver regenerates to maintain the health of the host. Moderate to massive hepatocellular necrosis occurs in the first 3 months postoperatively, with recovery by 4–5 months. Liver transplants 8–10 months postoperatively appear architecturally normal. No host liver tissues were found to be regenerating after subtotal host liver resection. We conclude that portal vein reconstruction without hepatic arterial inflow can sustain a partial liver transplant in the long term, replacing the function of the host liver. © 1999 Wiley-Liss, Inc. MICROSURGERY 19:78–82 1999

A total of 847 inbred Lewis rats of mixed sex were used in this pancreaticoduodenal (Pd) donor aging study. Pd grafts were taken from 9- to 12-month-old donors and transplanted into 3-month-old recipients (thus, the first generation Pd graft, or 1 Pd). After 9 to 12 months, the same Pd grafts were again harvested and transplanted into 3-month-old rats (thus the 2 Pd generation). This cycle was repeated to obtain the 3, 4, and 5 Pd series. Sequential transplantation was able to extend the Pd grafts' mean survival time to 32 months for fourteen 4 Pd grafts, and to 39.2 months for four 5 Pd grafts (the longest lived graft survived for 42 months). The pancreas and duodenal sections of the grafts remained normal throughout the entire study. However, the aortic sections of the grafts (which were harvested to include the superior mesenteric and celiac arteries) all exhibited moderate to massive atherosclerotic changes by the 5 Pd mean survival age of 39.2 months. Such histological changes commenced even before 21 months of Pd graft age in some animals, gradually progressing to dilation of the aorta (and subsequent narrowing of aortic tributaries), as well as formation of an eggshell-like inner membrane shielding the aortic intima, by 42 months. Such atherosclerotic changes precluded transplantations beyond the 5 Pd series.

A total of 847 inbred Lewis rats of mixed sex were used in this pancreaticoduodenal (Pd) donor aging study. Pd grafts were taken from 9- to 12-month-old donors and transplanted into 3-month-old recipients (thus, the first generation Pd graft, or 1 Pd). After 9 to 12 months, the same Pd grafts were again harvested and transplanted into 3-month-old rats (thus the 2 Pd generation). This cycle was repeated to obtain the 3, 4, and 5 Pd series. Sequential transplantation was able to extend the Pd grafts' mean survival time to 32 months for fourteen 4 Pd grafts, and to 39.2 months for four 5 Pd grafts (the longest lived graft survived for 42 months). The pancreas and duodenal sections of the grafts remained normal throughout the entire study. However, the aortic sections of the grafts (which were harvested to include the superior mesenteric and celiac arteries) all exhibited moderate to massive atherosclerotic changes by the 5 Pd mean survival age of 39.2 months. Such histological changes commenced even before 21 months of Pd graft age in some animals, gradually progressing to dilation of the aorta (and subsequent narrowing of aortic tributaries), as well as formation of an eggshell-like inner membrane shielding the aortic intima, by 42 months. Such atherosclerotic changes precluded transplantations beyond the 5 Pd series.

A historical review of the literature concerning replantation and transplantation of reproductive organs has included studies from this laboratory, using rats, over the past 25 years. From the basic observation of ischemic and traumatic injury due to the transplantation, syngeneic testicle transplants, resulting in a partner's impregnation and histological restoration of the testicles, led to human testicular transplantation. As to the ovarian transplants, granulosa‐theca cell tumors may transform into malignancies if followed for a prolonged period as intrasplenic ovaries, and high doses (15 to 20 mg/kg b.w.) of azathioprine can produce such malignant tumors in a shorter period. By caval‐portal shunt, ovarian hormones enter directly into the portal blood stream and no typical granulosa‐theca cell tumors were produced, owing to the fact that the liver cannot degrade all the hormones secreted by both ovaries. While en‐bloc vagino‐utero‐ovarian transplantation in the rat is possible, no impregnation has been yet achieved. Finally, it is hypothesized that those who have acquired microsurgical techniques and have a full understanding of the anatomy of the reproductive system will not only be able to perform replantation of the penis, but also will be capable of allogeneic transplantation of genital organs, whether ethically approved or not, and sooner than one may think. In such cases a penile part may be obtained at a sex‐change surgery or from a cadaveric donor, similar to other vital organ transplantation practices. © 1995 Wiley‐Liss, Inc.

A technical update on rat kidney transplantation is given. In this study, the bladder-bladder union was made using silk, polyglycolic acid (Dexon), polyglactin (Vicryl), and chromic catgut. The propensity of these sutures to form vesical calculi was investigated in both first and second generation transplants. The results of our study indicate that there is no significant difference (P greater than 0.01) in their calculogenic ability. Special problems attendant with first and second generation kidney transplants are described. The concept and technique of second generation kidney transplants are also described.

Forty‐five Sprague‐Dawley rats were divided into four groups. The first two groups were subjected to primary epineural anastomoses, with and without tension. In the remaining two groups, sciatic nerve defects were produced and femoral cable grafts were then performed with and without making an epineural sheath defect on the edge of the recipient nerves. Five functional evaluation criteria (sensation, push‐off, fanning of claws, cubital ulcer, and leg atrophy) were used along with histological findings. It has been found that the recovery of sensation was the least in the tension group, as was other functional recovery. Animals with epineural and fascicular sutures ranked highest in functional recovery while cable grafts followed at 4th, 10th, and 12th week of observation.