It is good of you to show interest in the Polish twin's separation report. It was intended to announce this happy story of compassion and international cooperation creating a better future for these twins. The modern name of this phenomenon is “conjoint twins”. There are many types of conjoint twins and I refer you the following references [₂,₃,₄] There is no similarity between any twins except generally from site of connection let it be the head, the thorax, and the pelvis. There would be also parasitic organs like another head without body or third leg or half a body. That's why most of these conditions would be incompatible with life. Those who reach medical attention are the lucky few. Ethically it would be better to separate these twins so they can lead respectable productive lifes.

'Siamese twins' are like the famous twins Eng and Chang, born in 1811 to a hard-working peasant family. The twins were discovered in 1824 by Robert Hunter, then living on the river in Bangkok. “His eye was caught by a strange object moving through the water,” says one account by the American missionary Dan Beach Bradley. “It was a creature that appeared to have two heads, four arms and four legs, all of which were moving in perfect harmony. As Mr. Hunter watched, the object climbed into a nearby boat, and to his amazement he realized that he had been looking at two small boys who were joined together at the chest”. [₅] Hunter saw the commercial possibilities of exhibiting Eng and Chang and eventually persuaded both their mother and the Thai authorities to let them be taken abroad. They left on April 1, 1829 and never returned to their native land Siam.

Over the next 45 years, the boys traveled extensively appearing before enthusiastic crowds under various management, including that of the great showman P.T. Barnum. During this time they learned to speak and write English fluently and generally impressed all who met them with their charm and intelligence not to mention the extraordinary coordination with which they performed athletic tricks. Medical studies were made and several proposals were made to sever the thick band of flesh that joined them, but these were never attempted because of the unknown dangers involved.

Figure 1

The twins eventually became American citizens and, settling on North Carolina, married two sisters, Sarah and Adelaide Yates. The unconventional marriages were, by all accounts, happy; Chang and Adelaide had ten children in all, while Eng and Sarah had twelve. They lived in separate houses, a mile apart, and for 25 years alternated between the two, with the twins spending three days at each.

On January 16, 1874 at Mt. Airy house, Chang died because he had been drinking heavily and his health became frail. The doctor found a blood clot in his brain. Eng also died 3 hours later because he was shocked by the death of his brother. They were born together and they also died together at age of 63. They had a total of 21 children. Eng had 11 children, and Chang had 10 children. None of them were twins.

As far the technicalities of surgery: could they have gotten surgical separation? The simple answer is yes.

The bodies would be scanned to see if there is enough organs for each baby and if not what is needed to secure safe separations. There would be involvement of two surgical team for surgery and reconstruction of the body. There would be intraoperative monitoring and support of all body systems; cardiovascular respiratory excretory systems. There would be a neurologist who would monitor the course of nerves so they would be preservation of the function. The Polish twins took over than ten hours of separation. A medical case report cannot be given here except after institutional and family consent.

I hope that these slight details about this operation would satisfy your interest.
Thank you for sharing this information and best regards